2-channel Dolby Digital Recording Panasonic DVD recorders can record Dolby Digital programme material as two channel stereo.
2K 2K is a picture format. Usually it refers to 1536 lines with 2048 pixels and describes a 4 x 3 aspect ratio picture. This is not a television format but
35mm film is often scanned to this resolution for use as 'digital film' for effects work and, increasingly, grading, cutting and mastering. For publishing
in television, a 16:9 (1080 x 1920), and a 4 x 3 aspect ratio window can be selected from the 2K material for HD and SD distribution. The format is
also suitable to support high quality transfers back to film or for D-cinema exhibition.
2-pass See multipass.
2-way Most loudspeakers have two drive units. The tweeter is the smaller unit and handles higher frequencies while the larger woofer is for mid to
lower frequencies. The electronic circuitry inside the speaker features a crossover. This sends the signals from an amplifier to the appropriate drive
unit - in a 2-way speaker, high frequency signals are sent to the tweeter and lower ones to the woofer. 3-way speakers also exist and you may come
across speakers that have more than two drive units in each cabinets. But note, that these speakers can only be described as 3-way if their
crossovers filter and send signals three ways
2.25 MHzThis is the lowest common multiple of the 525/59.94 and 625/50 television line frequencies, being 15.734265 kHz and 15.625 kHz
respectively. Although seldom mentioned, its importance is great as it is the basis for all digital component sampling frequencies both at SD and HD.
2:3 pull downConverting 24 frames-per-second of motion picture film and 24P video, onto television using 60 fields or frames-per-second refresh
rate - such as 525/60i, 1080/60i and 720/60p requires the 24 frames to be mathematically converted to 60 fields or frames. 3:2 refers to three and
then two of the television's 60 fields or frames being mapped to two consecutive film frames. The sequence repeats every 1/6th of second, after four
24 frames-per-second frames and 10 television frames at 60p, or 10 fields at 60i.The visual effect of 3:2 pull down is a juddering movement - as
three, then two frame/fields are assigned to the same 1/24-second original time interval. American viewers hardly notice the effect however it is
evident to many viewers in 50Hz countries e.g. UK, Australia.Ideally 3:2 pull down should be confined for display purposes but otherwise should be
avoided. For example, standards conversion from, say 525/60 to 625/50, starting out with 3:2 pull down material will cause excessive motion
artefacts at the output. For animated graphics it is impossible to work directly from 3:2 material for reference as most of the 60 Hz interlaced frames
(pairs of fields) are made up fields from two different 24 Hz frames. 3:2 can also be regarded as inefficient as there is 'unnecessary' repeating of
material (fields). DVDs for the 525/60i (NTSC) market hold motion picture material stored at 24 fps and the 3:2 operation is executed in the player. In
addition, if 3:2 pull down material were recorded or broadcast, its motion artefacts would cause MPEG compression to be less efficient, requiring
more data bandwidth or lowering the quality of the compressed image.
2.35:1 Known as Cinemascope, this is the widest aspect ratio commonly used by movie-makers
3:2 Pull-down What telecines must do to produce 60Hz field rate video. This means taking one film frame at 24fps(24Hz) and reproducing the frame
twice, followed by taking the subsequent frame and reproducing it three times. (12 frames doubled = 24, 12 frames tripled = 36 totalling 60). The
resulting motion artefacts can prove disagreeable. 3:2 Pulldown Recognition or 3:2 Inverse Telecine: Film is usually recorded at 24 frames per
second. NTSC video (North America) is 30 frames (60 fields) per second. In order to get smooth motion, the film frames are broken into video fields
in a 3-2-3 sequence. 3 fields for the first film frame, 2 fields for the second film frame, and so on. If a line doubler doesn't compensate for the extra
field during playback on a progressive-scan display, the image will have noticeable motion artifacts. A line doubler with 3:2 pulldown recognition or
3:2 inverse telecine can see this sequence in the signal and correct for it by making sure the last field in the first frame isn't mixed with the first field
of the second frame.
3D RGB Frame Noise Reduction In this noise reduction system, a separate circuit is used for each of the three RGB colors. Suppressing noise
particularly at low illumination levels, these circuits allow bright, detailed recording even in dim lighting.
3ivX Video format based on MPEG-4 video standard with certain modifications. 3ivX can be compared pretty easily to DivX ;-) format, but in this
comparision 3ivX unfortunately loses in quality (at least currently, 10/2001). 3ivX is pretty popular format among Apple MacIntosh users, because of
its extensive support for Mac. In other hand, Windows users have stayed away from this format because in its original format, 3ivX had to be stored
in QuickTime file structure instead of AVI file structure -- most of the Windows-based video editing tools don't support QuickTime, but either AVI or
ASF instead.
4:2:2 Decoding Description not yet available
4:3: Aspect ratio of the NTSC TV screen, with "4" unit width corresponding to "3" unit height, proportionally, regardless of the actual size of the
screen. 4:3 - Aspect ratio with "4" unit width corresponding to "3" unit height, proportionally, regardless of the actual size of the screen. The format
used for most standard televisions.
5.1 AUDIO or AC3: The Dolby Digital audio standard selected for DTV. This system consists of six audio channels: Left, Center, Right, Left Rear,
Right Rear, and subwoofer. For the time being, only high end HDTV programs will utilize Dolby Digital audio. 5.1 Surround Sound - Form of
surround sound in which five speakers are positioned around the viewer/listener, while the sub-woofer (the .1) is placed in front.
8-VSB: Eight discreet amplitude level, "vestigial side-band" broadcast transmission technology. VSB is an analog modulation technique used to
reduce the amount of spectrum needed to transmit information through cable TV, or over-the-air broadcasts used in the NTSC (analog) standard. 8VSB is the U.S. ATSC digital television transmission standard.
12 degree DDR DMD A new development of the Texas Instruments digital light processing (DLP) engine which greatly increases contrast ratio.
13.5 MHzSampling frequency used in the 601 digital coding of SDTV video. The frequency was chosen to be a whole multiple of the 525 and 625line TV system frequencies and was high to most accurately represent the 5.5 MHz of luminance information present in SD images. Digital sampling
of most HD uses 74.25 MHz, which is 5.5 times 13.5 MHz.ITU-R BT.601
16:9: Aspect ratio of widescreen DTV formats for all HDTV and some SDTV (Standard Definition) video. "16" unit width corresponds to "9" unit
height, proportionally, regardless of the actual size of the screen. 16:9 - Aspect ratio of widescreen DTV formats for all HDTV and some SDTV
(Standard Definition) video. "16" unit width corresponds to "9" unit height, proportionally, regardless of the actual size of the screen
24P Means 24 frames per second progressive scan images, emulating the traditional way film images were captured It can refer to the HDTV picture
format with 1080 lines and 1920 pixels per line (1080 x 1920/24P) however it is also used at SDTV at 480 and 576 lines with 720 pixels per line. 24p
SDTV is often used as an offline for an HD 24P edit, or to create a pan-and-scan version of an HD down conversion.
100Hz Super Digital ScanA conventional PAL analogue TV set emits a signal at a frequency of 50 frames per second - 50Hz. Our eyes are
sensitive to this frequency and at times a 50Hz picture appears to flicker. 100Hz technology digitally creates a replica of each frame and inserts it
after the one before. This significantly reduces flicker. But it still does not produce a completely smooth picture (especially with fast motion video).
Panasonic has therefore enhanced standard 100Hz technology with Advanced 100Hz Super Digital Scan and other unique picture enhancing
features such as Acuity.
601 Refers to the ITU (old CCIR) recommendation for the colour difference component of digital video and defines 4:2:2 sampling at 13.5MHz with
720 active lines. It was chosen to work with both 525/50 and 625/60 using multiples of 2.25MHz, the lowest common sampling pattern.
720i One of the resolution specs used in the HDTV. 720i stands for resolution of 1280x720 pixels and the magic little 'i' means that the video is in
interlaced format. Other common HDTV resolutions are 1080i and 720p.
720p One of the resolution specs used in the HDTV. 720p stands for resolution of 1280x720 pixels and the magic little 'p' means that the video is in
progressive format. Other common HDTV resolutions are 1080i and 720i.
1080i 1080 lines, interlace scan. 1080i does not indicate the frame rate which can be 25, 29.97 or 30 Hz and is defined by SMPTE and ITU (ITUR.BT 709). This is the very widely used format which is defined as 1080 lines, 1920 pixels per line, interlace scan. 1080i One of the resolution specs
used in the HDTV. 1080i stands for resolution of 1920x1080 pixels and the magic little 'i' means that the video is being interlaced. Other common
HDTV resolutions are 720i and 720p.
1080P1080 x 1920 pixels scanned progressively. Frame rates can be similar to those for 1080i (25, 29.97 and 30 Hz) as well as 23.976, 24, 50,
59.94 and 60 Hz.
A
AAC Advanced Audio Compression coding provides high quality compressed digital music files in the SD formatAAC AAC stands for two things:
either MPEG-2 Advanced Audio Coding or MPEG-4 Advanced Audio Coding and as its full name suggests, it is either an MPEG-2 or MPEG-4-based
audio format. The MPEG-2 version of the format is also often called as MPEG-2 NBC as in Non-backwards compatible, but the correct name that
should be used, is the AAC. The NBC name comes from the fact that unlike older MPEG audio encoding methods, it is not backwards compatible
(for example, MP3 is backwards compatible to MP2) to older MPEG audio formats.
MPEG-2 AAC produces better audio quality than MP3 using
less physical space for the files and MPEG-4 AAC produces better quality and smaller files than MPEG-2 AAC.
ABA Australian Broadcasting Authority
ABR Average Bitrrate is basically just one form of Variable Bitrate where the encoder tries to maintain specific average bitrate for the file so that
the actual size of the resulting file could be estimated more easily. To achieve a situation where you tell the encoder that you wish to use a specific
ABR and that the encoder would actually do exactly that requires usage of multi-pass encoding technology. As there aren't currently any audio
encoders available that can use multi-pass encoding, true respect-the-ABR-I-want-to type of encoding is possible only with video encoding. On the
other hand, ABR can also simply state the average bitrate of a VBR encoded video or audio clip.
Absorption: Reduction of acoustical energy usually by converting it into heat via friction using soft, fibrous materials.
AC-3 5.1 Channel Digital Audio Compression SystemAC3: Audio Codec 3. This was the original and more technical name for Dolby Digital.
Replaced by marketing mavens when they realized that Dolby's name was not in the title. Some RF modulated, 5.1-encoded laser discs were
labeled as AC3. Later versions were labeled as Dolby Digital. AC3 See Dolby Digital. AC3 - See Dolby Digital.
ACA Australian Communications Authority
Academy Curve: An intentional roll-off in a theatrical system's playback response above ~2kHz (to -18dB at 8kHz) to minimize noise in mono optical
tracks. Some (many) transfers to home video of mono movies have neglected to add the Academy filter during transfer, giving many old movies a
screechy sound they were never intended to have. A few home processors have an Academy filter option, making them a must for old-movie buffs.
Has been used since 1938.
ACATS Advisory Committee on Advanced Television Systems (USA)
Access Channels US term for dedicated 'public service' channels set aside by cable companies for non-discriminatory access to the network by
the public, government agencies, or educational institutions.
Access Network The local loop or last mile of a carrier network which reaches the customer's premises, also referred to as the local drop in the
US.
Access Node (AN) Part of the Access Network which performs some or all of the following: Modulating forward data onto the Access Network
Demodulating return-path data Enforcing the MAC protocol for access onto the Access Network Separating or classifying traffic prior to multiplexing
onto the Transport Network;such as differentiating traffic that is subject to QoS guarantees from traffic that receives best-effort support. Enforcing
signaling Handling passive operations, such as splitting and filtering.
Accounting Separation Regulatory requirement for dominant companies (usually telcos) to operate separate accounts for different activities to
avoid unfair cross subsidies (EG telephony, Internet access and video offering).
Active Power circuitry containing transistors, such as amplifiers, power supplies or converters.
ACI Adjacent Channel Interference
Acoustic Suspension: A sealed speaker enclosure that uses the air trapped in the cabinet as a reinforcing spring to help control the motion of the
woofer(s).
Active: Powered. An active cross-over is electrically powered and divides the line-level signal prior to amplification. An active speaker includes an
active crossover and built-in amplifier.
Active Matrix: Term used to describe LCD Displays which have micro-transistors that "open" and "close" each pixel. Active Matrix Each pixel has
an individual controller which allowing the brightness and colour of every pixel to affect the overall picture.
Active Matrix TFT: A common type of LCD used in laptops, cameras, and LCD projection panels that were produced in the late 1980s to early
1990s. A typical active matrix TFT display is a single panel of LCD glass that controls all three primary colors. TFT displays are noted for their quick
response time and their ability to display full motion video and animations without image ghosting.
Active Speaker All speakers need amplification. Most speakers are passive so they need to be driven by an external amplifier. An active speaker
has a built-in amplifier and therefore does not need to be driven by an external one. Many subwoofers designed for home cinema use tend to be
active.
AcutanceThe measure of a lens performance or of picture quality in terms of sharpness of the transition across the boundary between the images of
light and dark areas
Acuity Core TV picture quality is determined by factors such as edge delineation, gradation and signal-to-noise ratio. Creating super-high-quality
pictures requires precise control over these factors. Panasonic's Acuity Core TV technology does this. It is the world's first platform that provides full
10-bit processing of all video signals in real time, from input all the way through to output. The new Acuity function combines a range of technologies
including increased horizontal and vertical resolution, a new 3D Comb Filter and improved Motion Compensation.
A/D Analog to Digital
Addressable Able to signal from the headend or hub so that only the particular specified subscriber's receiving equipment is affected, enabling
changes in the subscriber's level of service for premium channels/PPV etc.
ADSL Asymmetric Digital Subscriber Line. A method of enhancing the bandwidth of twisted pair copper cable to speeds of more than 500 Kbps —
often 2Mbps, the minimum to deliver video — and up to 6Mbps. Although two way, as the name suggests the data transfer is uneven, with more
bandwidth downstream. Also see xDSL.
Advanced Artificial Intelligence Keeps contrast levels high, whilst maintaining focus and detail levels.
Advanced Dynamic Sharpness Controls sharpness in selected areas.
Advanced Progressive Scan Instead of the standard field by field interlace method this system displays all active lines at once as a complete
frame. The result is a picture that is superbly sharp and clear.
Advanced Simple Profile is one of the video encoding layers of MPEG-4.
It is best understood as an addition to MPEG-4's Simple Profile video encoding. ASP adds the following technologies over SP, but is otherwise
exactly like SP: B-frames, ¼ pel motion compensation, extra quantization tables and global motion compensation.
Advanced VSS Advanced Virtual Surround Sound creates a surround sound effect by simulating surround channel sounds using only 2 front
speakers. The advanced section creates a wider range from left to right. This effect does not work on karaoke discs
Ariel plant
Generally US - cable suspended in the air on telephone or electric utility poles. Not usually allowed in Europe.
AFC Automatic Frequency Control
AGC Automatic Gain Control
Algorithm: A formula or set of steps used to simplify, modify, or predict data. Complex algorithms are used to selectively reduce (compress) the high
digital audio and video data rates. Algorithms are formulated to selectively reduce the data rate without affecting picture quality.
Aliasing: Defects or distortion in a television picture or audio. Defects are typically seen as jagged edges on diagonal lines and twinkling or
brightening. In digital video, aliasing is caused by insufficient sampling or poor filtering of the digital video. Aliasing Aliasing is a problem associated
with interlaced video sources and affects sharp lines and edges during camera movement. Interlaced images are made up of two fields which make
up each frame. The first field contains the odd numbered scan lines (1,3,5,7,9 etc.), the second field contains the even lines. In a panning where a
given object is moving on the screen, it will have moved a small distance between field one and field two in effect meaning that the field one "half"
object will be slightly out of line with the field two "half" object which causes the object to appear to shimmer. As soon as motion stops, the problem
disappears. Depending on specific symptoms this is sometime known as "combing" of "twittering".
ALIS ALIS Method (Alternate Lighting of Surfaces Method) High definition and high brightness is realized by displaying 1024 scanning lines with
same 512 lines of scanning electrodes as conventional system, by discharging alternately the spaces between the display electrodes and the
scanning display electrodes not being used in the conventional system.
Alternative access provider A telecommunications provider, other than the local telephone company, that provides a connection between a
customer's premises to a point of presence of the long distance carrier.
AM: Amplitude modulated.
Ambient Light The level of lighting in a room (such as daylight, artificial lighting etc.) present in a room other than the light emitted by the projector.
The higher the ambient light level the brighter the projector needs to be to give a viewable image.
Amplifier A component that increases the gain or level of an audio signal. Amplifier A device the boosts the strength of an electronic signal. In a
cable system, amplifiers are spaced at regular intervals throughout the system to keep signals picture-perfect regardless of how far your live from the
headend.
Amplitude Modulation The process of impressing information on a radio-frequency signal by varying its amplitude. Generally amplitude
modulation is due for the purpose of relaying messages by voices, television, facsimile or other modes.
Analogue: Compared to digital formats, analog is the older form of electronic signal transmission. Analog is transmitted in frequency, while digital
signals are transmitted in codes Analogue A way of storing data using electrical signals. An analogue TV tuner uses radio frequencies which are
susceptible to interference. Digital components - such as TVs, radios, recorders, video players, etc, use digital signals which are less prone to
interference and offer enhanced quality, ease of use and greater versatility. ANALOGUE: The first system used to broadcast Channel 8. Analog
television uses a series of wavelengths to represent picture elements. DTV uses data consisting of 1s and 0s to represent that same information.
Analogue broadcasting
Conventional broadcasting in which the picture, sound and other information is transmitted as a continuous wave form which is a direct
representation of the source material.
Analogue (data transmission) Signals in the form of continuously variable physical quantities.
Analogue Device A devise that operates with variables represented by continuously measured quantities such as voltages, resistances, rotations
and pressures.
Analogue Signal A signal that is solely dependent of magnitude to express the information content.
Analogue -To-DigitalA device that converts a signal whose input is information in analogue form and whose output is the same information in digital
form.
Anamorphic: Process that horizontally condenses (squeezes) a 16:9 image into a 4:3 space, preserving 25 percent more vertical resolution than
letterboxing into the 4:3 space. For the signal to appear with correct geometry, the display must either horizontally expand or vertically squish the
image. Used on about two or three promotional laser discs and many DVDs. Also called Enhanced for Widescreen or Enhanced for 16:9.
Anamorphic Watch a wide aspect ratio on a conventional 4:3 TV set and you either get big black bars across the top and bottom or the film is
'panned and scanned' so that you only get the central part of the image filling the screen. Either way, you're not getting the whole picture. Most
movies on DVD are presented in their original aspect ratio and a widescreen TV is the first step in getting to see the whole image. But because the
picture is not an exact fit for the screen's 16:9 shape, you may still get black bars at the top and bottom of the screen. A DVD with an anamorphic
widescreen picture gives enhanced quality and digitally squeezes the sides of the picture forcing it upwards and downwards to fill the screen. A
widescreen TV then decodes the anamorphic code and a 1.85:1 picture fits perfectly onto a widescreen. An anamorphic 2.35:1 transfer will still
have those black bars, but they'll be much smaller. Anamorphic filming technique was developed to make widescreen movies using 4:3 film. An
anamorphic lens distorts the image picked up by the camera before it reaches the film. By using a similar lens when projecting the film back on
screen, the correct, intended aspect ratio is restored. Similar technique is used to store 16:9 video material at 4:3 aspect ratios. Anamorphic 16:9
video is common in DVD movies and DVB broadcasts. When movies with an aspect ratio above 1.80:1 (1.78:1 to be exact) are converted to
anamorphic widescreen format, they need to be letterboxed to maintain a correct aspect ratio without cropping. For a visual, easy to understand
explanation of anamorphic video, please see the World's Easiest Explanation of Anamorphic 16:9 WidescreenEnhancement in DVDs.
Anamorphic Lens: An anamorphic lens is a lens that has different optical magnification along mutually perpendicular radii. This provides the ability
to project a source image of one aspect ratio, such as 4:3, into a different aspect ratio, such as 16:9, by using different magnifications for the
horizontal and the vertical dimensions of the projected image.
Anamorphic Widescreen: Video that has been enhanced for use on widescreen televisions. Sometimes the configuration for a regular TV results in
artifact, but an anamorphic widescreen is still a better picture than VHS or laserdisc. Also referred to as "16 x 9 enhanced" or "widescreen."
ANSI American National Standards Institute.
ANSI Contrast: Contrast is the ratio between white and black. The larger the contrast ratio the greater the ability of a projector to show subtle color
details and tolerate extraneous room light. There are two methods used by the projection industry: 1) Full On/Off contrast measures the ratio of the
light output of an all white image (full on) and the light output of an all black (full off) image. 2) ANSI contrast is measured with a pattern of 16
alternating black and white rectangles. The average light output from the white rectangles is divided by the average light output of the black
rectangles to determine the ANSI contrast ratio. When comparing the contrast ratio of projectors make sure you are comparing the same type of
contrast. Full On/Off contrast will always be a larger number than ANSI contrast for the same projector.
ANSI Lumens Brightness measured in "candles". A measurement of brightness is taken across several areas of the light source and an average
taken to give the ANSI lumens.ANSI Lumens: A standard for measuring light output, used for comparing projectors. Unfortunately, there are enough
variables, that the eye will often disagree radically with the ANSI rating. At best, ANSI lumens do fairly well comparing "apples" to "apples". If
however one projector uses Halogen lamps and another metal-halide, the halogen projector will seem noticeably dimmer even if the two units rate
the same. Other variables, including type of LCD technology (active matrix TFT, Poly-Si, passive), type of overall technology (LCD vs.DLP vs. CRT),
contrast ratios, etc. all effect the end result.
Antenna An structure or devise used to receiving or transmitting electromagnetic waves.
Antenna Array A group of identical antennas arranged and interconnected for achieving greater directivity (gain) or beam shaping.
Antenna Stack Antenna tower with multiple antennas and supports.
Apparatus licence A licence authorising the use of a radiocommunications transmitter within the Broadcasting Services Bands (See ABA 12).
Aperture Working much like the pupil of the eye, the movement of the lens' internal aperture blades closes or opens the aperture to adjust the
amount of light passing through the lens. The value inscribed on the aperture ring of the lens (F1.4, F2, F2.8, etc.) represents the size of the aperture
and is called the "aperture value" or "f-stop." As this value increases, the aperture narrows, or is "closed," and as it decreases, the aperture widens,
or is "opened." Apeture The diameter of hole behind a lens through which light is allowed to pass. Measured in f-stops, the larger the value, the
more light can get through the lens. The pay off is in reduced depth of field. Aperture: In television optics, it is the effective diameter of the lens that
controls the amount of light reaching the photoconductive or photo emitting image pickup sensor.
Aperture Correction : Compensation for the loss in sharpness of detail because of the finite dimensions of the image elements or the dot-pitch of
the monitor.
Archive: Off-line storage of video/audio onto back-up tapes, floppy disks, optical disks, etc.
Arcing Aspect ratio conversions
Artifact: Something in a video picture that was not originally there. For example, on some DVDs you may see "pixelization," or computerized blocks
of color or black space. This is a result of poor DVD mastering, poor compression or if your player or TV has been set wrong. Consult your
equipment manuals to remedy the latter. ARTIFACTS: Imperfections in the DTV signal, known as "glitches" in analog television. The most common
artifacts are small black or white blocks in the picture, called "pixilation", or pops and clicks in the audio. Artifacts: Undesirable elements or defects
in a video picture. Most common in digital are macroblocks, which resemble pixelation of the video image, and pops and clicks in audio.
ASCII: American Standard Code for Information Interchange. A standard code for transmitting data, consisting of 128 letters, numerals, symbols,
and special codes, each of which is represented by a unique binary number. An ASCII word typically is 8 bits of binary data.
ASF Advanced Streaming Format. Microsoft's new audio/video format, meant specifically for streaming purposes. It doesn't specify how the video
or audio should be encoded, but instead just specifies the structure of the video/audio stream. This means that ASF files can be encoded with
basically any audio/video codec and would still be in ASF format. Many times ASF is confused with Microsoft's implementation of MPEG-4 video
format, because most of the ASF streams are encoded using this technology.
a-Si: "Amorphous Silicon"
Aspect Ratio: The width to height ratio of an image on a TV. Aspect Ratio The ratio of width to height of a display or screen. The most common are
4:3 or 1.33:1 and 16:9 or 1.78:1. Aspect Ratio: The ratio of image width to image height. Common motion-picture ratios are 1.85:1 and 2.35:1.
Television screens are usually 1.33:1 (also known as 4:3), which is similar to the Academy standard for films in the '50s. HDTV is 1.78:1, or 16:9.
When widescreen movies (films with aspect ratios wider than 1.33:1) are displayed on 1.33:1 televisions, the image must be letterboxed,
anamorphically squeezed, or panned-and-scanned to fit the screen. Aspect Ratio Describes the shape of a screen: a box that is 16cm wide and 9cm
high is therefore 16:9. Movies are shot in a particular ratio for particular types of screens. There are four main aspect ratios: 4:3 the shape of a
conventional TV and used by older films 16:9 widescreen: a compromise between 4:3 and the wider formats used by film makers 1.85:1 letterbox:
the most commonly used picture format 2.35:1 Cinemascope: The widest of the most common ratios and also expensive. Used for the ultimate
widescreen experience. Aspect Ratio: The most popular aspect ratio is 4:3 (4 by 3). Early television and computer video formats are in a 4:3 aspect
ratio, which means that the width of the image is 4/3 times the height. Examples: A 15 inch monitor is 12 inches wide by 9 inches high (9 x 4/3 =
12). A resolution of 640x480 is a 4:3 format (480 x 4/3 = 640). Other formats are 5:4 used by the 1280x1024 SXGA resolution, 16:9 is used by
HDTV, and 3:2 for 35mm slides. Aspect ratio
The aspect ratio to the ratio of the width of the screen to the height. The two relevant digital TV formats are 16:9 (widescreen) or 4:3 (the current
screen ratio). ASPECT RATIO: The ratio between the width and height of the television screen. There are two main aspect ratios used in DTV.
16:9 (16 units of width to 9 units of height) is the aspect ratio used for all high definition and widescreen standard definition digital broadcasts. When
programs recorded in the 16:9 format are broadcast on a traditional 4:3 analog television, they have black bars at the top and bottom of the screen.
This is called a "letter box."
4:3 (4 units of width to 3 units of height) is the aspect ratio used in today's analog television sets. When programs recorded in a 16:9 format are seen
on a 16:9 unit, the black bars filling the screen on either side of the picture are called "side bars". They can also be called "Windowshades" or a
"Pillarbox". An easy way to compare 4:3 to 16:9 is to think of 4:3 as 12:9. Aspect Ratio: The ratio of a television picture width to height. In NTSC
video, the standard is 4:3. In HDTV and SDTV widescreen video, it is 16:9. Aspect ratio Easiest way to explain aspect ratio is to say that it means
the ratio between the width of the picture and the height of the picture. Normal TV's aspect ratio is 4:3 (1.33:1), HDTV's aspect ratio is 16:9 (1.85:1)
and CinemaScope movies' aspect ratio is 2.35:1. Aspect Ratio - The ratio of a television picture width to height. In NTSC video, the standard is 4:3.
In HDTV and SDTV widescreen video, it is 16:9.
ASPI Advanced SCSI Programming Interface is an old high-level interface written for accessing data stored on SCSI devices. It was developed by
Adaptec, and welcomed by developers frustrated with complexity of the SCSI hardware layer. ASPI layer is also used to control ATAPI CD-ROM
devices connected to an ATA (IDE) bus.
Asynchronous: Lacking synchronization. In video, a signal is asynchronous when its timing differs from that of the system reference signal.
Asynchronous transfer mode (ATM) The transfer mode in which the information is organised into cells. It is asynchronous in the sense that the
recurrence of cells containing information from an individual user is not necessarily periodic.
ATA Rated Case: A case rated strong enough to be shipped by common carrier; freight lines, UPS, FedEx, etc. Most cases of this type are easily
recognized by their metal reinforced corners and handles. These cases are often referred to as "Anvil cases" bearing the name of one of the
manufacturers.
ATM cell A digital information block of fixed length (53 octets) identified by a label at the ATM layer.
ATSC: Advanced Television Systems Committee. Government-directed committee that developed our digital television transmission system. ATSC:
"Advanced Television Systems Committee." Formed to establish technical standards for U.S. advanced television systems. Also, the name given to
the 8-VSB transmission standard itself. ATSC and DVB
The acronyms for the US and European formal standards for digital television.
§ ATSC - Advanced Television Systems Committee (US)
§ DVB - Digital Video Broadcasting (Europe)The standards provide for a wide range of technical and other specifications for digital television
broadcasting. They may have similarities - for example, both use the same compression system for the video signal. The most significant difference
is in the modulation system adopted for the radiofrequency signal carrying the information. ATSC Advanced Television Systems Committee (USA)
Attenuate: To turn down, reduce, decrease the level of; the opposite of boost. Attenuation The decrease in amplitude of a signal between any two
points in a circuit. Usually expressed in decibels. Attenuation is the opposite of amplification.
ATV Advanced Television
Audio
Relating to sound or its reproduction; used in the transmission or reception of sound.
Audio D/A conversion CD and DVD players need to convert digital signals into analogue so that we can hear them. Panasonic DVD portables use
high quality converters for superb sound and they can feature a sample rate of up to 192kHz/24-bit. That means the player samples 24-bit chunks of
digital data 192,000 times before it delivers the optimum sound signal.
Audio In & Out Most projectors have several audio connectors allowing both sound output from the computer to be connected and external
amplifiers and speakers.
Authoring Authoring means, in video world, a process where already-encoded video files are transferred into a specific format that describes how
the data should be kept on storage media, such as CD or DVD. Most common use of the term is when speaking of DVD authoring, using a separate
DVD authoring software that allows users to create menus, chapter selections, etc to the disc's layout in addition to the actual video file(s) and
transfer this structure to filesystem that can then be burned to a DVD. Other authoring processes include VCD authoring and SVCD authoring. In
both processes, authors can create menus and chapter selections and various other tasks before the structure is ready for CD burning, pretty much
like in DVD authoring (just in more limited scale).
Auto Balance : A system for detecting errors in color balance in white and black areas of the picture and automatically adjusting the white and black
levels of both the red and blue signals as needed for correction.
Authoring Systems Authoring systems are software packages that allow a user with very little or no programming experience to develop interactive
multimedia packages to aid in training & education. Examples of authoring systems are Macromedia Authorware and Asymetrix ToolbookAVI "Audio
Video Interleave". AVI is the file extension and used for, and a reference to, a "Video for Windows" file.
Automatic Gain Control (AGC)
Automatic Slope Control (ASC)
Used to protect a device from optical overload while maintaining bandwidth and sensitivity performance.
Circuitry which permits amplifier response compensation for varying slope (tilt) at its input.
Available bit rate (ABR) An ATM layer service where the limiting ATM-layer transfer characteristics provided by the network may change
subsequent to connection established.
AVC Full description not available yet. Advanced Video Coding, also known as MPEG-4 part 10, or MPEG-4 AVC. The codec has been developed
in a joint ITU-T venture called Joint Video Team. It is also known as H.264.
AVI Audio Video Interleave. This is a container video format that specifies certain structure how the audio and video streams should be stored
within the file. AVI itself doesn't specify how it should be encoded (just like the streaming format ASF), so the audio/video can be stored in very
various ways. Most commonly used video codecs that use AVI structure are M-JPEG and DivX ;-). AVI contains code called FourCC which tells what
codec it is encoded with.
A-Weighting: Measurement based roughly on the uneven frequency sensitivity of the human ear. The influences of low and high frequencies are
reduced in comparison to midrange frequencies because people are most sensitive to midrange sounds.
AWGN Additive White Gaussian Noise
AXIS (Advanced Pixel Interpolation System) AXIS uses pixel interpolation data obtained by differential calculation to precisely process the CCDs'
output. This maximizes the effect of the Quad-Density Pixel Distribution, helping to produce clear, high-contrast images.
B
Backbone Microwave System A series of directional microwave paths carrying common information to be relayed between remote points;
engineered to allow insertion of signals, dropping off of signals and switching of signals along its length at designated relay points.
Back Channel: A means of communication from users to content providers. Today, a simple type of back channel is an Internet connection using a
modem.
Background Noise In an amplifier or other device that draws current, there is always some noise output in addition to the desired signal.
Backlit: Refers to a remote control, or on projector control panel, that has buttons and controls that are illuminated. This is a major asset when using
the projector in a darkened or semi-darkened room. Many projectors have backlit remote controls, while the number of projectors with backlit control
panels is much smaller. As projectors have gotten brighter, room lights tend to stay on, so while nice, having backlit controls is no longer important to
many users.
Back Room Projector: A projector with a "long-throw" lens designed to be used from the far back of the room, often in a projection booth, balcony,
or back of an auditorium. Many typical projectors have third party lenses available for "long-throw" applications.
Balanced Input: A connection with three conductors: two identical signal conductors that are 180 degrees out of phase with each other, and one
ground. This type of connection is very resistant to line noise.
Banding The effect of waves or bands of the same color on a digital graphic. Banding often occurs in images that include finely graduated transitions
from one color to another or on colour printers when a line of colour slightly overlaps the previous line.
Bandpass: A two-part filter that cuts both higher and lower frequencies around a center band. A bandpass enclosure cuts high frequencies by
acoustic cancellation and low frequencies by natural physical limitations on bass response.
Bandwidth The frequency (cycles per send) measured in Hertz. Bandwidth: In audio, the range of frequencies a device operates within. In video,
the range of frequencies passed from the input to the output. Bandwidth The amount of data (audio or video) transmitted in a given time.
Bandwidth: The number of cycles per second (Hertz) expressing the difference between the lower and upper limiting frequencies of a frequency
band; also, the width of a band of frequencies. BANDWITH: The range of frequencies over which a signal is allocated for transmission. KAET's
analog and digital transmitters are each allocated 6 megahertz (MHz) of bandwith in which to transmit its signal by the FCC. Bandwidth: The
complete range of frequencies over which a circuit or electronic system is allocated to function. In transmission, the U.S. analog and digital television
channel bandwidth is 6 MHz. Bandwidth A measure of the information-carrying capacity of a communication channel. The bandwidth corresponds
to the difference between the lowest and highest frequency signal which can be carried by the channel.
Basic Cable The basic program services distributed by a cable system for a basic monthly fee. These include one or more local broadcast
stations, distant broadcast stations, non-pay networks and local origination programming.
Bass: Low frequencies; those below approximately 200 Hz.
Bass Reflex When a loudspeaker produces sound, volumes of air move around inside its cabinets. Big air shifts mean bigger bass. But smaller
speakers do not have the physical dimensions to create trouser-flapping lower frequencies. This where a bass reflex port comes in. This is a vent
which forces air out from inside the cabinet. Forcing air out in such as way can help smaller speaker enclosures deliver more impactful bass. Bass
Reflex: See Port.
BAT Bouquet Association Table (part of SI)
Baud: A unit of signaling speed equal to the number of signal events per second. Baud is equivalent to bits per second in cases where each signal
event represents exactly one bit.
Baud Rate The measure of the speed of transmission of a digital code.
BER Bit Error Rate BER: "Bit error rate." Bit errors are caused by interference, or loss of signal, so the stream of bits composing the DTV picture is
disrupted. A measure of the errors in a transmitted signal.
Betacam: An analog video taping system using a 1/2-inch tape cassette, developed by Sony. Digital versions include Digital Betacam and Betacam
SX.
BetaMax Full description not available yet. BetaMax -- "The better format". You can still hear this from people who used to have BetaMax videos
in 1980s and who are now forced to move to VHS compatible VCRs or to digital VCRs because lack of blank tapes, etc... BetaMax was developed in
1970's by Sony to offer consumers the same possibility for video recording as they did have for audio recording. BetaMax was the first one to offer
certain functions that we nowadays take as granted -- they provided first HiFi videos, first "tape remaining" counters, peek search, Automatic
Program Search (in VHS systems nowadays called as "indexing"), etc... BetaMax also had better resolution than rival formats, because it used more
tape for each second than other formats. This was also the flaw that eventually gave VHS the winning edge -- American consumers didn't give a shit
about quality of their recordings, but instead they wanted to fit as much video as possible into one tape. In Europe currently all the VHS systems
have SP/LP options that allows you to choose double recording time (and obvisouly, reduced quality) -- in U.S. all the VCRs have also XP or EP
option that allows users to fit triple the recording time to one tape (means: already crappy VHS quality/resolution is divided by three). BetaMax and its
"big brother", BetaCam, are nowadays de facto in professional TV companies, producing companies and other video editing companies, although
digital video is finally killing this format (just like it is killing all the other analogue formats), but that will take many, many years. For more information
about BetaMax, please check out this site: http://www.palsite.info/home.html
Beta SP Video tape format used in professional quality video production.
Binary: A numbering system using the digits "0" and "1" in the decimal system. All computer programs are executed in binary form.
Bipolar: 1) The condition of possessing two pole sets. In a conventional (non-FET) transistor, one pole set exists between the base and collector,
and the other pole set exists between the base and emitter. 2) Speakers that consist of two driver arrays facing opposite directions and wired in
electrical phase with one another to create a more diffuse soundstage.
Bit In computer and digital terminology a bit is the smallest unit of data. It is expressed in binary notation so that it is either 0 or 1 - basically an 'off' or
an 'on' switch. The word 'bit' is an amalgam of 'binary' and 'digit'. BIT: The smallest increment of DTV digital information. A bit is a one or a zero. For
the purposes of digital television signals, bits are counted in groups of a million each (Megabits, or Mb). To transmit the DTV signal, the transmitter
sends out 20 Megabits (20 million bits) per second (Mb/s) Bit: Binary digit. The smallest unit of data in a digital system. A bit is a single one or zero.
A group of bits, such as 8-bits or 16-bits, compose a byte. The number of bits in a byte depends upon the processing system being used. Typical
byte sizes are 8, 16, and 32. Bit A binary digit. The binary systems of numbers is often called base 2. All binary digits consist of combinations of 0's
and 1's.
Bit Error Rate (BER) The fraction of bits transmitted that are received incorrectly.
Bitmap: 2-dimensional array of pixels representing video and graphics.
Bit Rate A bit is a binary digit representing two different states either ON or OFF. The bit rate is the number of discreet bits of data transmitted in a
given time Bitrate Very often used when speaking of video or audio quality -- defines how much physical space one second of audio or video takes
in bits (note: not in bytes). For example: 3 minutes of MP3 audio in 128kbit/sec CBR bitrate takes 2.81 megabytes of physical space (1,024 x
128 / 1,024 / 1,024 x 180 / 8). Another term that is very often used -- specially with videos -- when speaking of filesize, is the framerate
Bit Rate The rate of a binary-coded transmission which is the number of bits per second.
Bitstream: A continuous series of transmitted bits.
BitTorrent Description not available yet
Bi-Wiring: A method of connecting an amplifier or receiver to a speaker in which separate wires are run between the amp and the woofer and the
amp and the tweeter.
Black Level: Light level of the darker portions of a video image. A black level control sets the light level of the darkest portion of the video signal to
match that of the display's black level capability. Black is, of course, the absence of light. Many displays, however, have as much difficulty shutting
off the light in the black portions of an image as they do creating light in the brighter portions. CRT-based displays usually have better black levels
than DLP, plasma, and LCD, which rank, generally, in that order.
Blackspots An area of poor or non-existent reception of one or more of the 'potentially available' television services with a signal strength of less
than 50 dBuV/m2 and/or on International telecommunications Union (ITU) Picture Quality rating less than 3.The 'potentially available' television
services are the ABC, SBS and any commercial services licensed to serve an area that includes the 'black spot' area.
Blu-Ray Full description not available yet. Currently (spring 2002), everything what we know about Blu-Ray is based on speculations as the
format doesn't exist yet. Basically Blu-Ray is a name for a new DVD standard which uses blue-violet laser instead of old red laser discs used in CDs
and in DVDs. This allows manufacturers to store more data using the same amount of disc surface. One Blu-Ray disc will hold appx. 27GB of data
(compared to 4.36GB on regular DVD) on one side/layer of the disc. It is developed mostly because Japan is going to start digital terrestial television
broadcasting in beginning of 2003 and consumers will demand a high-quality recordable media for their new high-definition medium. Video will be
stored using MPEG-2 technology, just like in DVD-Video discs, but in much higher bitrate. Currently DVD-Video discs can have a bitrates upto
9.8Mbps, but Blu-Ray discs support bitrates as high as 36MBps. For more tech specs, visit this site.
BNC connector "Bayonet Neill Concellman". A type of connector commonly used on high end video equipment which provides a secure
connection for shielded cables using a bayonet. (some like to call it the british navy connector) BNC - Stands for Bayonet Neil-Concelman (or
sometimes British Naval Connector) and is used as a connector between a large variety of different electrical devices.
Boost: To increase, make louder or brighter; opposite of attenuate.
B-pictures Bidirectionally predictive pictures (motion) compensation
Bridger Amplifier Trunk amplifiers serve to boost the signal and pass it along, and to provide branching lines, called feeders, for distribution of the
signals to subscribers. The bridger amplifier is housed in the same case as the trunk amplifier. It taps the trunk at about +20 dBmV and splits the
signal into 2 to 4 feeder lines.
Bridged Tap Wires that are connected to a network, in which one end of the wire is unconnected to proper termination equipment. (Ex: A
consumer or technician removes devices without completely disconnecting to the old device.)
Bridging: Combining two channels of an amplifier to make one channel that's more powerful. One channel amplifies the positive portion of an audio
signal and the other channel amplifies the negative portion, which are then combined at the output.
Brightness: For video, the overall light level of the entire image. A brightness control makes an image brighter; however, when it is combined with a
contrast, or white level control, the brightness control is best used to define the black level of the image (see Black Level). For audio, something
referred to as bright has too much treble or high-frequency sound. Brightness: The attribute of visual perception in accordance with which an area
appears to emit more of less light. (Luminance is the recommended name for the photo-electric quantity which has also been called brightness.)
BROADBAND: A term describing the amount of bandwith assigned to a channel. Both analog and digital television are considered broadband
signals. Broadband is sometimes referred to as "the pipe" or "the highway". Broadband: Capable of handling frequencies greater than those
required for high-grade voice communications. Broadband Any system able to deliver multiple channels and/or services to its users or
subscribers. Broadcast television, cable television, microwave and satellite are examples of broadband technologies.
Broadband Modulation The transfer of information by a radio signal requires a certain minimum amount of spectrum space. This minimum
depends on the rate at which this information is conveyed. Sometimes called wideband modulation.
Broadcasting The dissemination of any form of radio electric communications by means of Hertzian waves intended to be received by the public.
Transmission of over-the-air signals for public use.
Broadcast addresses A predefined destination address that denotes the set of all service access points.
Brouter A device that routes specific protocols, such as TCP/IP and IPX, and bridges other protocols, thereby combining the functions of both
routers and bridges.
BRR Bit Reduction Rate.
BSB Broadcasting Services Bands - The legal term for the parts of the radiofrequency spectrum used for transmitting radio and television services
(further detail is provided under 'Channels' below).
BST-OFDM Band Segmented Transmission Orthogonal Frequency Division Multiplex
Built-in digital surround decoder A portable with a built-in decoder means that you don't need a Dolby Digital or DTS processor - simply connect it
to any mul-channel amp for digital surround sound.
Built in loop through The display device has a "loop through" to allow a second display device (e.g. a screen or another projector) to be connected
and display the same signal.
Burn-In: When stationary graphics are onscreen for long periods of time, the continuous image can "burn" into the screen, resulting in a ghostly
after-image superimposed over anything you watch. This is most common on rear projection sets.
Burst error second Any errored second containing at least 100 errors.
Bus A LAN topology in which all the nodes are connected to a single cable. All nodes are considered equal and receive all transmissions on the
medium.
B/W - Black and White
Byte 8 bits or 256 discreet items of information such as colour, brightness etc. One full frame of CCIR 601 requires just under 1 Mbyte of storage.
One full frame of HD/24p uncompressed video requires approximately 9 times the amount storage Byte A data unit of eight bits Byte: A group of
data bits that are processed together. Typically, a byte consists of 8 bits. There are kilobytes, Megabytes, Gigabytes, Terabytes, etc.
1 Byte = 8 bits
1 kilobyte = about 1,000 bytes
1 Megabyte = about 1,000,000 bytes
1 Gigabyte = 1,000,000,000 bytes
1 Terabyte = 1,000,000,000,000 bytes
C
CA Conditional Access
Cable Loss Defines the amount of cable loss that an amplifier is aligned (pre-equalised) through during factory alignment. Aligning an amplifier
through cable creates a tilted gain response.
Cable Modem: A data modem that uses the bandwidth of a given cable system. Because cable modems provide Internet access over cable, they
are much faster than modems that use typical phone lines.
Cable-Powered Devices obtaining ac power simultaneously with RF on the coaxial cable.
CableSCAN A software product developed by TapSCAN which tabulates Nielson household and demographic data for cable.
Cable System Facility that provides cable service in a given geographical area, comprised of one or more headends.
Cable Termination RF frequency signals travelling in coaxial cable will reflect off any impedance that does not match the 75 Ohm impedance of
the cable. This will cause serious signal distortion. For this reason, the ends of all the trunk and distribution cables are terminated with a 75 Ohm load
to ground.
Cache: Storage of digital data (video, audio, text, etc.).
Cam In this particular case, with Cam we mean a specific method how movie pirates create illegal bootleg copies of original movies. Cam method is
basically just a guy who uses either regular or professional camcorder to shoot the movie either from TV or actually inside a movie theatre (in some
Cam copies of movies you can actually see audience as well :-). These bootleg copies are normally then encoded into VCD, SVCD or DivX format
and distributed illegally over the Internet.
Capture Process where you record TV broadcasting to your computer's harddrive using video capture cards. For more information, please take a
look at our capture guide.
Carrier An alternating-current wave of constant frequency, phase and amplitude. By varying the frequency, phase or amplitude of a carrier wave,
information is transmitted.
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) The Ethernet media access method. All network devices contend equally
for access to transmit. If a device detects another device's signal while it is transmitting, it aborts transmission and retries after a brief pause.
Carry-on Case: Refers to a projector with carrying case that fits into the overhead bin or under the passenger seat of an airline. A projector case that
does not fit these conditions will need to be checked as luggage, and ride in the cargo area of the airline. Make sure you have a good hard case
when checking a projector as luggage. A projector is a delicate device that can have its LCDs misaligned when not handled properly.
Cascading Crossovers: Two crossovers used in series on the same signal in the same frequency range causing greater attenuation of the out-ofband signal. For example, using the crossover in a receiver's bass management setting and the one in a subwoofer simultaneously will create an
exaggerated loss of signal.
Cascade Depth
The number of amplifiers between the headend and the specific subscriber.
CAT Conditional-Access Table (part of SI)
Cathode Ray Tube: (CRT) Analog display device that generates an image on a layer of phosphors that are driven by an electron gun.
CATV Community Antenna TeleVision Also called Cable TV. Widely used as a synonym for Cable TV.
CBR Full description not available yet. CBR stands for Constant Bitrate. Basically it is a term that describes how video or audio is encoded -constant bitrate means that the bitrate doesn't vary during the video or audio at all, but is same through the clip. CBR bitrates are very easy to use in
calculations -- if you have an MP3 file that has CBR of 128kbit/sec and it lasts for 3 minutes, the amount of HDD space it takes can be calculated
easily:
128kbit = 128 x 1024 bits 1 byte = 8 bits 1 kilobyte = 1,024 bytes 1 megabyte = 1,024 kilobytes 3 minutes = 180 seconds
180 x 128 x 1024 / 8 / 1024 / 1024 = 2.81MB
CCD: Charged Couple Device- the key image-processing component. A semiconductor chip which coordinates photosensors (pixels) to turn a
picture into electronic signals. Most cameras have a 1 chip but the best is a 3CCD unit with a chip for each color element (red, green and blue). The
higher the number of pixels the more information can be resolved resulting in a better picture.
CCI Co Channel Interference
CD: Compact Disc. Ubiquitous digital audio format. Uses 16-bit/44.1-kHz sampling rate PCM digital signal to encode roughly 74 or 80 minutes of
two-channel, full-range audio onto a 5-inch disc. CD Compact Disk
CD-R Audio CD recorders (and also PCs with CD writers) now use two types of blank CD to record sound. CD-Recordable was developed first and
is a 'write once' system. That means you cannot erase so if you make a mistake while recording, that's it! When blank CD-Rs first appeared on the
market in the late 1980s, they cost around ?16 for a 60-minute disc and the recorders were ?3000 plus! Today, a blank CD-R which offers over 70
minutes of record time can be had for around ?1 and recorders are a fraction of the original price. While most modern CD players can handle
homemade recordings on CD-R, some older models may not be able to cope with such discs. CD-R: Recordable Compact Disc
CD-ROM - Compact Disc Read-Only-Memory. Similar to an audio CD but used for data storage
CD-RW Unlike CD-Rs, CD-RWs are Re-Writable so they can be erased and recorded over again. Great for making the perfect music CD. But take
care - not all CD players can playback recordings made on CD-RWs as the format's disc structure differs slightly from conventional audio CDs. CDRW: Rewritable Compact Disc
CDV See LaserDisc
cDVd See miniDVD.
CEA: Consumer Electronics Association. An association of manufacturers of consumer electronics products.
Cell ATM layer protocol data unit.
CEMA: "Consumer Electronics Manufacturers Association." An industry group that represents manufacturers of consumer electronics products.
Center Channel: The center speaker in a home theater setup. Ideally placed within one or two feet above or below the horizontal plane of the left
and right speakers and above or below the display device, unless placed behind a perforated screen. Placement is important, as voices and many
effects in a multichannel mix come from this speaker.
Central office (CO) The central location in a traditional public network telecommunication environment where access is available to signals
travelling in both the forward and reverse paths.
CGA Color Graphics Adapter First color-graphics standard for PC platform, developed by IBM back in 1981. Offered a resolution of 300x200 and
four colors.
Channel: In components and systems, a channel is a separate signal path. A four-channel amplifier has at least four separate inputs and four
separate outputs.Channel A signal path of specified bandwidth for conveying information.
Channel Capacity The number of channels available for current or future use on a cable system.
Channels Television broadcasts use particular areas of radiofrequency spectrum, which have been set aside for the purpose.There are two areas known as the VHF (very high frequency) and UHF (ultra high frequency) bands used in Australia. In Australia, each band is divided into a number of
equal width channels, each 7 MHz wide. The channels in the bands are numbered sequentially (VHF is divided into channels 1-12, UHF channels
28-69). Each broadcaster uses a channel for its main transmitter and might use other channels for smaller, local area transmitters.
Chaoji VCD See SVCD.
China Video Disc See CVD.
Chroma A video picture can be seen to be made up of two elements, the chroma made up of colour information and the luminance made up of
colour intesity. When you adjust the saturation or hue of the picture, you are adjusting the chroma characteristics.
Chroma Keying: The process of overlaying one video signal over another, the areas of overlay being defined by a specific range of color, or
chrominance, on the foreground signal.
Chromatic Aberration: An optical defect of a lens which causes different colors or wave lengths of light to be focused at different distances from the
lens. It is seen as color fringes or halos along edges and around every point in the image.
Chromaticity: The color quality of light that is defined by the wavelength (hue) and saturation. Chromaticity defines all the qualities of color except
its brightness.
Chrominance: (C) The color portion of a video signal. Chrominance: A color term defining the hue and saturation of a color. Does not refer to
brightness. Chrominance - A video signal carrying only the point-to-point colour, both hue and saturation, of a video image and not its brightness.
C/I Carrier to Interference
CIF Common Image Format ( Common Intermediate Format) . Back in history, this acronym's name comes from video conferencing tools in late
1980's and early 1990's. Nowadays the term CIF is used to mean specific video resolution: 352x288 in PAL 352x240 in NTSC CIF is 1/4th of "full
resolution" TV, also called as D1 and is best-known because VideoCD standard uses this resolution.
CineAlta The family of HD /24p products from Sony. The generic name of HD 24p includes the fact the system can record and play out in 24p, 25p
(as with European film shot as 25fps), 30p and even 29.97p(for Japan).
Class H+ A typical receiver's amplifier may not be sufficient to handle extremely high peaks, particularly those needed for the kinds of explosive
effects present in movie soundtracks. The Class H+ amplifier has been developed to provide extra 'headroom' and therefore prevents distortion at
high volume. It is also very efficient, therefore creating less heat.
Cliff Edge Effect: An RF (radio frequency) characteristic that causes DTV reception to deteriorate dramatically with a small change in signal
reception. Bit error rate increases to the point where video cannot be obtained by the receiver. The picture and audio are lost entirely.
CLIFF EFFECT: When approaching the fringes of reception, analog TV pictures begin to degrade by becoming "snowy." With DTV its all or nothing.
In an area with a weak digital signal, a relatively small reduction in signal strength may cause the DTV signal to abruptly change from perfect to
nothing; hence the name "cliff effect."
Clone: An exact digital copy, indistinguishable from the original.
Closed Captioning: Text stream included in broadcast signal that provides narrative description of dialogue, action, sounds, and other elements of
the picture. Most often used by the hearing impaired and in environments where audio is undesirable (such as in restaurants).
Cluster The group of homes passed by a single fibre node.
CMYK "Cyan Magenta Yellow Black" One of the two prevailing color models in use for electronic publishing. CMYK imaging is the central concept in
four-color printing. This system is based on the principle that all colors can be created by combining the proper amounts of Cyan, Magenta, Yellow,
and Black. The CMYK color model is an "additive" scheme, in which white (or blank) is defined as the abscence of all four source colors and all tones
are created by adding the appropriate amounts of the necessary colors.
C/N Carrier to Noise
Coaster Coaster is a slang term for an optical disc (CD, DVD, etc) that doesn't work, normally because of bad quality of the optical disc itself, failure
during the CD/DVD burning process, etc. So, such disc just creates an excellent, shiny coaster to use with your latenight pint.
Coated Optics: A variety of materials are put on to high quality lenses for several reasons. One of the key reasons is to minimize the amount of light
reflected back to the lamp, and the amount of ambient light that mingles with the focused light leaving t he lens. Generally good coatings can add
15% or more to the lenses brightness. Other coatings are used for filtering colors/
Coaxial There are two types of cables and sockets used to connect digital audio equipment. Optical cables use thin fibre optic leads. Coaxial (or
electrical) cables are thicker and the sockets look the same as conventional RCA connectors. Arguably, coaxial digital cables offer better
performance but optical ones can be easier to use and hide. Coaxial: 1) A speaker typically with one driver in the middle of, and on the same axis
as, another driver. 2) An audio or video cable with a single center pin that acts as the hot lead and an outer shield that acts as a ground. Coaxial - A
type of two-signal connector in which an inner conducting wire is surrounded by a shielding cylindrical outer conductor; commonly used in audio and
video connections.
Coaxial Cable: A thick cable comprised of an inner wire and braided outside wire. Used to feed cable programming to TVs, among other things.
Sometimes called coax cable. Coaxial cable Actual line of transmission for carrying television signals.Cable with a central copper strand for
transmitting electrical signals, surrounded by a concentric air or insulation (nonconducting) core, and enclosed by an outer (electrically shielding)
concentric metal fibre, either braided or solid. Even where a cable plant uses fibre optic cable from its headend,, coaxial cable is usually used from
the node to the subscriber household (from the kerb).
Co-Channel A form of interference caused by another signal occupying the same channel frequency. Example - two signals are received in a
headend, from different locations, causing interference with each other as received.
Codec (compressor-decompressor) A circuit or software module used to compress and/or decompress data. When an analog video signal is
converted to a digital signal, the resulting digital data is a massive 20MB per second. The codec is used to compress this data for recording (for
example, to a memory card), and then to decompress it to its original form for playback Codec: Mathematical algorithms used to compress large data
signals into small spaces with minimal perceived loss of information. Codec: "Coder-decoder." A device that converts analog video and audio signals
into a digital format for transmission. Also converts received digital signals back into analog format. Codec Codec stands for Coder/Decoder.
Basically it is a piece of software or a driver that adds a support for certain video/audio format for your operating system. With codec, your system
recognizes the format the codec is built for and allows you to play the audio/video file (=decode) or in some cases, to change another audio/video file
into that format (=(en)code). For example, when you install Windows to your home computer, Windows installs automatically bunch of most
commonly used codec into the system, so you don't have to download them separately from their vendors. Despite that, there are some codecs that
are widely used, but not installed automatically by Windows -- most notably DivX ;-), MPEG-2 and in some cases (old Windows versions, like Win95)
MPEG-1 codecs.
Code Division Multiple Access (CDMA) A digital technology developed by QUALCOMM. With CDMA, unique digital codes, rather than separate
RF frequencies or channels, are used to differentiate subscribers.
CODFM Coded orthogonal frequency division multiplexing. COFDM Coded Orthogonal Frequency Division Multiplexing COFDM: "Coded
orthogonal frequency division multiplexing." COFDM can transmit many streams of data simultaneously, each one occupying only a small portion of
the total available bandwidth. The DTV standard used in Europe.
Collision The result of two network nodes transmitting on the same channel at the same time. The transmitted data is not usable.
Coloration: Any change in the character of sound (such as an overemphasis on certain tones) that reduces naturalness.
Color Dynamics: "The whitest whites, reddest reds, etc." High color dynamics are a result of dynamic range/contrast ratio's. When we describe a
unit as having excellent color dynamics, the practical description might be "rich colors, excellent definition, high contrast".
Colour banding Refers to the transition from one colour to another not being smooth. For example in a pitcure of a blue sky going from dark blue at
the top to light blue at the bottom, the picture will appear to be a series of solid strips rather than a smooth transition.
Colour depth The number of different colours that a device is capable of processing or displaying. Usually quoted in bits, for example, 16-bit colour,
32-bit colour etc.
Colour difference - A system of transmitting video information in which the colour signals contain the difference between a given primary colour
(red, blue, or green) and the luminance signal. The colour information on DVDs and in component-video signals is encoded in this way.
Colour temperature - The specific shade of white produced by a video monitor in response to a pure-white (luminance-only) input signal, measured
in degrees kelvin, or kelvins (K). Low colour temperatures produce a "white" that's tinted reddish-orange compared with the bluish "white" at high
colour temperatures. Colour Temperature: A method of measuring the "whiteness" of a light source. Metal halide lamps have very high
temperatures compared to halogen or incandescent lights.
Combiner A signal combining network which allows several discrete inputs to be added into a common bandwidth and having high isolation
between inputs. Also nay refer to a power combining network.
Combing Combing occurs with interlaced video sources and affects vertical lines during camera movement. Interlaced images are made up of two
fields which make up each frame. The first field contains the odd numbered scan lines (1,3,5,7,9 etc.), the second field contains the even lines. In a
panning where a given object is moving on the screen, it will have moved a small distance between field one and field two in effect meaning that the
field one "half" object will be slightly out of line with the field two "half object" which causes the object to appear to shimmer. This is due to the
"straight" line not actually being straight but being jagged.
Comb Filter - An electronic filter designed to separate chroma and luma information.
Commentary Track: A separate track of audio on the DVD that can include filmmakers, stars, etc., discussing the film as it plays.
Commercial Skip Commercials can be quickly edited out of a recording for seamless and continuous playback of a programme.
Common Image Format (CIF) The internationally accepted 1920 x 1080 pixels.
Common Path Distortion (CPD) The interference of return path signaling caused by the forward path. Often referred to as ingress - of particular
significance in interactive applications where the return path is being used to contact the cable headend.
Communications Satellite An electronic retransmission vehicle located in space in a fixed earth orbit. Signals are transmitted to the satellite from
earth station antenna, amplified and sent back to earth for reception by other earth station antennas.
Communication Server A dedicated, stand-alone system that manages communications activities for other computers.
Component: An element of your system such as a TV, a receiver, a subwoofer.
Component Video: Outputs on a DVD player or TV that deliver the highest level of video by splitting the signal into three digital parts. For
component video to work, the source (DVD player) and the set (TV) must have like outputs. Component Video: A signal that's recorded or
transmitted in its separate components. Typically refers to Y/Pb/Pr, which consists of three 75-ohm channels: one for luminance information, and two
for color. Compared with an S-video signal, a Y/Pb/Pr signal carries more color detail. HDTV, DVD, and DBS are component video sources, though
most DBS material is transcoded to component from composite signals. Component Video The video signal is separated into its component form
i.e. red, green and blue (RGB). For television, the signal is modified and referred to as YUV. It offers the highest quality of picture reproduction,
especially from a DVD source. Component video input connections are usually three RCA phono-type plugs colour coded red, green and blue. Often
labeled Y, Pb, Pr Component Video: Component Video is a method of delivering quality video (RGB) in a format that contains all the components of
the original image. These components are referred to as luma and chroma and are defined as Y'Pb'Pr' for analog component and Y'Cb'Cr' for digital
component. Component video is available on some DVD players and projectors. Component Video Delivers the best quality video image as it
contains all the origional components of the image as opposed to the compression used in composite video. The two commonly used systems are
RGB and Y,R-Y,B-Y. RGB is simply the red,green and blue elements of the picture having one wire each. Y,R-Y,B-Y is slightly different in that Y
carries a black and white picture, R-Y the red element and B-Y the blue element. Green is extracted by taking the red and blue elements from Y and
whatever is left is green. Component video - A method of transmitting video signals that continuously keeps the various colour components
separate from each other.
Composite Audio: Another name for the standard RCA-jack audio outputs included on most DVD players and on all consumer-level audio
components. On most stereo components, this is a red-colored right output or input, and a white-colored left output or input.
Composite Triple Beat (CTB) In multichannel systems using push-pull, PHD, and feed-forward amplifiers, the limiting performance factor is
usually composite third order beats. The total number of beats that 'pile up' at a single frequency can be calculated. The composite triple figures are
with CW carriers at the output level and tilt listed on the specification sheets. Any deviation creates on a 2:1 basis. Worst-case CTB occurs at the
high end of the amplifier's passband. With TV modulated carriers, the average signal power is reduced. measured composite triple beat levels are at
least 6dB lower than with CW carriers, and possibly as much as 10 dB lower when frequency offsets are considered. the composite triple beat is
measured with a spectrum analyzer of 30 kHz resolution.
Composite Video: Another name for the standard RCA-jack video output. These outputs mix color as well as black and white signals together.
Results in an image that is not as sharp or clear as S- and component video. Composite Video: A signal that contains both chrominance and
luminance on the same 75-ohm cable. Used in nearly all consumer video devices. Chrominance is carried in a 3.58-mHz sideband and filtered out by
the TV's notch or comb filter. Poor filtering can result in dot crawl, hanging dots, or other image artifacts.
Composite Video Signal: The combined picture signal, including vertical and horizontal blanking and synchronizing signals.
Compound Loading: See Isobarik.
Compressed Resolution: Most projectors automatically accept images that are of greater resolution than the native (true) resolution of the
projector. The resulting image is scaled to fit the native resolution of the projector using a variety of scaling algorithms. Not all projectors use the
same compression algorithms; therefore, the quality of compression can vary. The nature of compression in a digital device means that some image
content is lost.
Compressed SVGA: Unlike CRT based monitors, LCD and DLP projectors only have one "true" resolution. Most projectors out there are VGA
(640x480) resolution. To project an 800x600 image to a VGA projector, the original 800x600 signal must be compressed down to VGA. This is done
by interpolating the data, and trying to best display all the information with only two thirds of the pixels (307,000 vs 480,000). The resulting image
gives you the SVGA page size, but some sacrifice of image quality. For the vast majority of people with SVGA laptops or desktops, they will have
more satisfying results, outputting VGA to a VGA projector.
Compressed SXGA: Found on XGA projectors, compressed SXGA handling allows these projectors to handle up to 1280x1024 SXGA resolution.
Most owners of XGA projectors that use the compressed SXGA are workstation users (SUN, SGI, IBM, HP...) The typical uses f or these
workstations are medical, life sciences, engineering and so on.
Compressed XGA: Found on SVGA projectors, compressed XGA handling allows these projectors to handle 1024x768 XGA resolution. How good
the compressed XGA is on a given model is a key factor in the decision process for most people choosing an SVGA projector. This is true as the
market shifts from SVGA laptops to those with XGA screens.
Compression: The process that allows films to be stored digitally on DVD. See also MPEG-2. Compression A process that uses an algorithm to
reduce data volume while preserving the original data content. Compression is used to reduce the time required to send and receive data over a
network, and to enable the recording of more data onto a memory card or other storage medium. Compression A process whereby the digital
signal is 'squashed' to fit a particular transmission capacity, by various mathematical processes. Compression Virtually all projectors and plasma
screens have the ability to accept higher resolution inputs than they are designed for (the exception is purely video projectors). For example a
projector designed for SVGA (800*600) will accept XGA (1024*768) input and compress it to SVGA for displaying. It is always preferable to specify a
display device designed for the resolution of your presentations as compression invariably involves some loss of detail.Compression is also used in
video systems. For example DVD's use MPEG-2 compression to fit reasonable amount of video onto a disk. Compression Compression expresses
the given picture with less data and compression rate alone does not give an indication of final picture quality. It is necessary to compress the data in
order to store and transmit digital television data using an economical amount of bandwidth. Different rates of compression are used with different
equipment and practically the more data used the better the image quality. Multiple generations of compressed images always result in image
degradation. COMPRESSION: Without compression, digital TV in the United States would not be possible. This process reduces the amount of data
required to represent a video or audio signal. Basically, using complicated mathematical equations you can squeeze more information into the same
amount of space without a noticeable difference in the picture quality. Compression: Reduction of the size of digital data files by removing
redundant and/or non-critical information ("data" being the elements of video, audio and other "information"). Digital TV in the U.S. would not be
possible without compression. Compression - Reduction of the size of digital data files by removing redundant and/or non-critical information ("data"
being the elements of video, audio and other "information"). Digital TV in the U.S. would not be possible without compression. Compression A
method for compacting the digital representation of a signal for more efficient transmission or storage.
Constant bit rate (CBR) A service class intended for real-time applications, or those requiring tightly constrained delay and delay variation, as
would be appropriate for voice and video applications. The consistent availability of a fixed quantity of bandwidth is considered appropriate for CBR
service.
Container In video terminology container or container format means a "wrapper" format, which doesn't define what compression formats (in other
words, what codecs) the video file within a specific container format includes, but rather defines how the video, audio and other possible data is
stored within the container. Best-known container formats are AVI and ASF.
Contour
Grade A The geographical boundary of an area receiving a given TV signal that is satisfactory for 70% of the viewers 90% of the time.
Grade B Borders of an area where the TV signal is satisfactory to at least 50% of the viewer locations 90% of the time.
Contrast: Relative difference between the brightest and darkest parts of an image. A contrast control adjusts the peak white level of a display
device. Contrast - In general, the range between the brightest and darkest parts of an image.
Contrast Ratio The ratio of brightness to darkness of a scene. Most projector and plasma screen manufacturers quote "full on/full off" contrast ratio
which is the difference between white light being displayed and black. Contrast Ratio: The ratio between white and black. The larger the contrast
ratio the greater the ability of a projector to show subtle color details and tolerate extraneous room light. There are two methods used by the
projection industry: 1) Full On/Off contrast measures the ratio of the light output of an all white image (full on) and the light output of an all black (full
off) image. 2) ANSI contrast is measured with a pattern of 16 alternating black and white rectangles. The average light output from the white
rectangles is divided by the average light output of the black rectangles to determine the ANSI contrast ratio. When comparing the contrast ratio of
projectors make sure you are comparing the same type of contrast. Full On/Off contrast will always be a larger number than ANSI contrast for the
same projector.
Controller: Generic term that typically refers to a combination preamp/surround processor or receiver. Can also refer to a handheld wireless remote.
Convergence: Adjustment of red, green and blue color on a rear projection set. The three CRTs inside a rear projection set occasionally need this
adjustment to ensure a sharp picture. Convergence The process used to produce a white image from the three primary colours (red, green and
blue). All three colours are placed on top of each other or, converged to produce 'white'.
Converter A device (in CATV) for permitting a standard TV set with a 12 channel VHF tuner to receive over 12 cable channels. Older types use a
multichannel TV tuner.
Copy Protection: Used on 99 percent of DVDs to prevent copying to VHS or other video formats. Home copying of DVDs to other formats is now so
difficult it's practically impossible, thanks to several different copy protection procedures employed by manufacturers. See also Macrovision.
CPE Common Phase Error
Critical Length Distance along a specific cable to cause worst-case mismatch reflection. A function of frequency-attenuation-velocity of
propagation parameters of specific cable types.
CRO Cathode Ray Oscilloscope
Cross Modulation 'Cross-mod' - A form of synchronous triple beat between any two channels where the modulation sideband (+/-)constitutes the
third beating frequency. More than one channel source may be additive and appear to be baseband (modulation) interference on the affected
channel.
Crosstalk
Noise passed between communications cables or device elements.
CRT: See Cathode Ray Tube.
Crystal Engine: The Crystal Engine is a special image processing circuit for 3CCD camera systems. Processing the signal from each of the three
CCDs independently, it gives both moving and still pictures exceptional quality.
CSS In video world, CSS means an annoying, relatively weak encryption scheme found on most DVD-Video discs. Historically CSS encryption was
cracked back in 1999 and first tool which allowed users to circumvent it (although it didn't exactly crack the CSS, but instead used leaked decryption
keys) was called DeCSS.
CTCS Commercial television conversion scheme
CTVA Commercial Television Australia (formerly FACTS)CRT: Cathode Ray Tube. Three CRTs (one each for red, green and blue) make up the
heart of a rear projection television.
Cut: To reduce, lower; opposite of boost.
CVD China Video Disc One of the original three applicants to replace VideoCD and sponsored mostly by Chinese government back in late 1990s.
Eventually it didn't win the competition -- SVCD became the 2nd generation video disc format in China and in the rest of the Asia. Anyway, as it
gained some popularity and is virtually identical to SVCD, most of the DVD players which support SVCD, support also CVD. CVD's main differences
to SVCD are the fact that it uses different subtitle format and the fact that it uses 352x480/576 resolution instead of SVCD's 480x480/576. This
makes is ideal format for storing data on CD waiting to be moved to DVD-R, because DVD-Video specs know CVD's native resolution -- and don't
recognize SVCD's resolution. So, by encoding movies directly to CVD format, you can store them on CD and play them with DVD player and at later
date, transfer the movie to DVD-R without re-encoding it.
CW Continuous Wave
D
D1 So-called "full resolution" for TV specs. Normally D1 can mean one of the following video resolutions: 704x576 (TV PAL) 704x480 (TV NTSC)
720x576 (DVD-Video PAL) 720x480 (DVD-Video NTSC) Subsets of D1 are CIF and QCIF.
D5: A tape format that is non-compressed component digital video which has provision for HDTV recording by use of about 4:1 compression (HD
D5).
D/A Digital to Analog
DAB Digital Audio Broadcasting
Damping: Of or pertaining to the control of vibration by electrical or mechanical means.
Damping Material: Any material that absorbs sound waves and eliminates acoustic energy by converting it into a different form. Fibrous material, for
example, turns acoustic energy into heat via friction.
D'Appolito: Vertically symmetrical driver array. Typically consists of a tweeter mounted between two woofers. Creates a more-vertically directional
sound with evenly spaced lobes in the off-axis response when compared with asymmetrical driver arrays.
DAT Full description not available yet. DAT can mean lots of things -- often it is used to refer to a certain tape backup format. In a/v terminology it
normally refers (at least most questions are focused on this one) to files that VideoCD has in its SEGMENT or MPEGAV directiories. These DAT files
are basically MPEG-1 files with an additional information and certain specific file structure -- they are NOT "real" MPEG-1 files and you need to
convert them back to "real" MPEG-1 files in order to edit them even that most of the software players treat them as regular MPEG-1 files.
DATACASTING: The DTV technology that allows KAET to use leftover bandwith not being used to transmit television programs to transmit data.
This data could include transcripts or web links, video, audio, text or graphics. This information could then be decoded by specially equipped
computers, set-top boxes, or DTV receivers. DTV's broadband channel allows information to be downloaded about 600 times faster than a personal
computer modem. Datacasting: Enhanced options offered with some digital programming to provide additional program material or non-program
related resources, allowing viewers the ability to download data (video, audio, text, graphics, maps, services) to specially equipped computers, cache
boxes, set-top boxes, or DTV receivers.
Data Communication The movement of encoded information by means of electrical transmission systems. Tthe transmission of data from one
point to another over communication channels.
Data Compression A technique that saves storage space by eliminating gaps, empty fields, redundancies, or unnecessary data to shorten the
length of records or blocks. Data Compression: A technique that provides for the transmission or storage, without noticeable information loss, of
fewer data bits than were originally used when the data was created.
Data rates Digital information is transmitted at a rate which is measured in digital bits per second or, more usually, millions of bits per second
(Mbits). The volume of digital bits that can be transmitted depends on the bandwidth of the medium used to carry them. A 7 MHz channel will be able
to carry approximately 19.353 Mbits per second when using the digital transmission standard chosen for Australia.
DAVIC
Digital Audio Visual Council - A technical standards setting body, particularly referred to in relation to cable modems.
dB: dB or decibel, is a measure of the power ratio of two signals. In system use, a measure of the voltage ratio of two signals, provided they are
measured across a common impedance. dB Decibel
DBPSK Differential Binary Phase Shift Keying.
DBS: Direct Broadcast Satellite. Term that replaced DSS to describe small-dish, digital satellite systems such as DirecTV and Dish Network. DBS
Direct Broadcast Satellite DBS: "Direct broadcast satellite." An alternative to cable and analog satellite reception utilizing a fixed 18-inch dish
focused on one or more geostationary satellites. DBS typically uses MPEG-2 encoding and QPSK transmission.
DCA Department of Communications and the Arts
DCITA Department of Communication, Information Technology and the Arts
DCP Digital Channel Plan. The assignment of technical specifications for each digital channel in a given area. Produced by the ABA in consultation
with the DTCPCG, industry and the public.
DCT Discrete Cosine Transform
DDS: "Digital Data Service."
Decibel (dB): A logarithmic measurement unit that describes a sound's relative loudness, though it can also be used to describe the relative
difference between two power levels. A decibel is one tenth of a Bel. In sound, decibels generally measure a scale from 0 (the threshold of hearing)
to 120-140 dB (the threshold of pain). A 3dB difference equates to a doubling of power. A 10dB difference is required to double the subjective
volume. A 1dB difference over a broad frequency range is noticeable to most people, while a 0.2dB difference can affect the subjective impression of
a sound. Decibel (dB) A unit of measuring relative levels of current, voltage, power or noise volume.
Decode Virtually all video and audio files have been encoded with some compression method, like DivX or MP3 and when we want to "open" these
files, we need to decode that compression. Decoding basically means opening a compressed file, whether its done by playing the file or by storing it
in an uncompressed format to HDD.
De-interlacer A device that converts an interlaced frame (which is the usual way of broadcasting images and comprises of the image being drawn in
two have - odd numbered scan lines then even) to progressive, which draws each scan line in sequence.
Delay: The time difference between a sonic event and its perception at the listening position (sound traveling through space is delayed according to
the distance it travels). People perceive spaciousness by the delay between the arrival of direct and reflected sound (larger spaces cause longer
delays). Delay The elapsed time between the instant when user information is submitted to the network and when it is received by the user at the
other end.
Demographics Breakdown of television viewers by such factors as age, sex, income levels, education and race.
Demodulation The extraction of the modulation or information from a radio-frequency current.
Demultiplexing See demux.
Demux Demuxing / demultiplexing basically means, when speaking of video formats, splitting the file that contains both audio and video data (and
possible other data streams as well, like subtitles), into separate files, each containing one element of the original file. Demuxing file doesn't weaken
the video nor audio quality, it doesn't do anything for these data streams, it just simply saves them into separate files. Opposite of demux is muxing,
which basically joins the datastreams back together.
Dense Wave Division Multiplexing (DWDM) A technology that provides in fibre the equivalent of frequency division multiplexing, in metallic wire.
Separate parallel channels are transmitted on a single fibre, with one wavelength for each channel. Current products enable 16 channels of 2.5 Gb
each for a total of 40 Gb per fibre. DWDM can operate over existing single-mode fibre, and therefore reduce upgrade costs.
Descrambler An electronic circuit that restores a scrambled video signal to its standard form.
Desktop Video: Video editing and production using standard desktop computing platforms running with add-on video hardware and software.
Detector The photodiode in optical receivers.
Diagnostics: Tests to check the correct operation of hardware and software.
Diagonal Screen: A method of measuring the size of a screen or a projected image. It measures from one corner to the opposite corner. A 9FT
high, 12FT wide, screen has a diagonal of 15FT. Throughout this document we assume that the diagonal dimensions are for the traditional 4:3 ratio
of a computer image as per the example above. Some screens are square, others particularly wide for 35mm slides 3:2 ratio. As such even if the
screen is 12x12, we would rate it 15FT diagonal since that would be the diagonal of the usable area. OK, how about this! Remember high school?
Here's your old geometry lesson. X-squared times Y-squared equals Z-squared. 3ft by 4ft screen = 3 squared (9), + 4 squared (16), equals 25 (5
squared) a 5 ft diagonal image.
Diaphragm: The part of a dynamic loudspeaker attached to the voice coil that produces sound. It usually has the shape of a cone or dome.
Dichroic: A mirror or lens that reflects or refracts selective wavelengths of light. Typically used in projector light engines to separate the lamps
"white" light into red, green, and blue light.
Diffusion: In audio, the scattering of sound waves, reducing the sense of localization. In video, the scattering of light waves, reducing hot spotting,
as in a diffusion screen.
Diffusor: Acoustical treatment device that preserves sound energy by reflecting it evenly in multiple directions, as opposed to a flat surface, which
reflects a majority of the sound energy in one direction.
Digital: Circuitry in which data-carrying signals are restricted to either of two voltage levels, corresponding to logic 1 or 0. Digital The use of a
binary computer code to represent information. In cable, digital transmission is much clearer than analogue. Digital technology also allows for more
information to be processed.
Digital8 Full description not available yet Digital camcorder tape format developed by Sony. Uses the same cassettes as analog Hi8 format, just
digitally.
Digital Audio Server: Essentially a hard drive, a digital audio server stores compressed audio files (like MP3 or WMA). Most include the processing
to make the files, and all have the ability to play them back.
Digital Betacam: A development of the original analog Betacam which records digitally on a Betacam-style cassette.
Digital broadcasting Broadcasting in which picture and other information is converted into, and transmitted as, a series of discrete 'bits' or numbers
which represent the picture or information being broadcast.
Digital Cinema The theatrical display of images that were originally created electronically but may be projected on film or electronically.
Digital Cinematography Digital acquisition using film-style operational practices.
Digital Coax Output: Transmits a digital audio signal via a digital coaxial cable. Similar in quality to a digital optical output, it is found on most midlevel and high-end DVD players and some CD players.
Digital Comb Filter: Filter that digitally separates color and black and white signals in your TV, providing a sharper picture and reducing artifacting
and shimmer. The best digital comb filters, called 3-line digital comb filters, compare three lines of video to ensure the best possible picture.
Digital compression An engineering technique for converting an analogue television signal into a digital format. A rule of thumb is that ten digital
channels fit into the spectrum of a single analogue channel.
Digital Disk Recorder (DDR): A video recording device that uses a hard disk drive or optical disk drive mechanism. Disk recorders offer nearly
instantaneous access to recorded material.
Digital Light Processing (DLP): The commercial name for this technology from Texas Instruments (TI): The technology inside is often referred to
as either "micro-mirrors", or DMD: It works this way: build a few hundred thousand tiny mirrors, and line them up in 800 rows of 600 mirrors each.
Now attach a hinge to each of those 480,000 mirrors. Attach each of those 480,000 hinges to its own very tiny motor! Power each motor with
electrostatic energy! The motors tilt their mirrors up to 20 degrees at incredible speeds. This allows the mirrors to modulate light from a lamp, and
send the "modulated signal" out through a lens, on to a screen. The most amazing part of DLP micro mirrors, is the scale of size. The 480,000
mirrors (actually 580,000 are used), hinges and motors are packed onto a "wafer" a bit larger than your thumbnail. Digital Light Processing (DLP) A technology developed by Texas Instruments that uses a Digital Micromirror Device to project video signals.
Digital Optical Output: Transmits a digital audio signal via a fiber optic cable. It is practically immune to magnetic or electrical interference. Similar
in quality to a digital coax output, it is found on most mid-level and high-end DVD players and some CD players.
Digital Output Allows DTS or Dolby Digital signals to be taken from a DVD player and fed to an external decoder.
Digital Micromirror Device (DMD) - A chip that contains a surface that is covered with more than half a million tiny movable mirrors. Used in the
DLP system to create video projectors.
Digital processing Digital signals need to be converted into analogue so that we can see or hear them. Panasonic TVs with an Acuity digital chassis
use high quality converters for superb picture quality and feature 10-bit processing at a sample rate of up to 60MHz. That means the processor
samples 10-bit chunks of digital data, 60 million times before it delivers the optimum picture signal.
Digital Rights Management See DRM.
Digital Set Top Box A device which accepts digital encoded television broadcasts and converts them to display on an analogue television set.
New boxes with added functionality provide local storage of programming on hard discs, and Internet access.
Digital Signal Processing Unique Panasonic digital signal processing technologies deliver true-to-life detail and color, with whiter whites, deeper
blacks, and superb rendering of fine details such as individual strands of hair.
Digital Theater Systems: See DTS.
Digital TV: TV capable of displaying digital or standard signals.
Digital Zoom: This increases the range of the optical zoom by electronically enlarging the image , bringing distant subjects up close.
D-ILA Direct Image Light Amplification. Technology patented by Hughes-JVC to improve the light output and contrast ratio over LCD panels. D-ILA:
Direct Drive Image Light Amplifier. This Hughes/JVC technology uses a reflective LCD to create an image. A light source is then reflected off the
reflective LCD and is directed through a lens to a screen.
DILA Direct Image Light Amplification. Technology patented by Hughes-JVC to improve the light output and contrast ratio over LCD panels.
Dipole: Speakers with drivers on opposite faces that are wired electrically out of phase, creating an area of cancellation to the sides. Recommended
by THX for use as surround speakers, with null directed at the listener to create a more ambient and non-localizable effect.
Direct Broadcast Satellite (DBS) A high-powered ku-band satellite capable of offering TV signals from a satellite to the home, for multichannel
reception, with a small (0.5m) antenna.
Direct linear drive The Direct Linear Drive motor provides constantly moving inner blades with 13.000 rpm even when battery level is getting lower,
or shaving thick hairs.
Direct-Stream Digital: A format for encoding high-resolution audio signals. It uses a 1-bit encoder with a sampling rate of 2,822,400 samples per
second (verses 44,100 for CD). Used to encode six high-resolution channels on SACD.
Direct-View Television: Display whose image is created on the surface from which it is viewed.
Direct View TV: TV capable of displaying a digital signal or a signal for standard TVs.
Dish Antenna A high-grain antenna, shaped like a dish, that is used for the transmission and reception of ultra-high-frequency and microwave
signals.
Dispersion: The spread of sound over a wide area.
Distant Signal A broadcast signal originating outside the cable system's local market.
Distortion: Any undesired change in an audio signal between input and the output. Distortion - Broadly speaking, any unwanted alteration of a
signal; usually, however, it refers to non-linear distortion, which adds to the output signal components that are mathematically related to the input
signal.
Distribution amplifier A product which allows one source signal to be amplified and distributed through multiple outputs. For example and RGB
signal from one computer could be output to several projectors or plasma screens. Most amps can be "piggy-backed" to allow as many outputs as
required. Distribution Amplifier: An amplifier used to maintain a clean noise free signal to the projector over significant distances. Even with good
heavily shielded cables, range of video and computer signals is limited to a few dozen feet before noticeable degradation. In ceiling mount situations,
where the wiring may pass along side or across electrical conduits, etc. a distribution amp may be needed with shorter distances. Many distribution
amps can also split the signal into 2 or more amplified signals for driving multiple projectors, projectors and monitors.
Distribution Quality: The level of quality of a program feed from a network to its stations.
Distribution system Part of a cable system consisting of trunk and feeder cables.
DivX A new legal version of DivX ;-) video encoding technology, released by company called DivXNetworks. Originally the development of DivX
codec went something like this: First there was Microsoft's MPEG-4 codec. Hackers made a more flexible version of it and started calling it DivX ;-)
(note the smiley -- name was a pun towards failed DIVX pay-per-view format). Then more people got into DivX ;-) and there became a reason to
build a compatible codec that wouldn't rely on stolen Microsoft code. They formed an open source development team, called at first as OpenDivX
and later on as Project Mayo. Out of this development, a commercial company, called DivXNetworks was launched. First commercial -- although
freely available -- codec that was developed by DivXNetworks was DivX v4. Some developers that were involved with the OpenDivX/Project Mayo
phase, didn't drop their open source idea and developed the codec further and now that sidekick is competing against DivXNetworks' "legal DivX"
and is called XviD.
DIVX (original) Full description not available yet. Now de-funct pay-per-view version of DVD-Video standard developed by Circuit City, an
American consumer electronics retailer. System was developed to compete against DVD-Video format. Each movie disc had to be activated and
each playback worked pretty much like a movie rental -- the player "dialed" to CircuitCity's servers when movie was being watched and checked if
user had any "credits" left to watch the movie. If not, device would allow user to purchase more credits to watch the movie.
DivX ;-) DivX ;-) was developed by bunch of hackers, most notably a guy called gej and it is based on Microsoft's version of MPEG-4 encoding
technology, called as Windows Media Video V3. Basically Microsoft's encoders didn't allow users to save MPEG-4 streams into AVI structure format,
but forced users to use ASF instead. It also had some other limitations -- and those limitations were overriden in DivX ;-). It also added a support for
other than Windows Media Audio audio encoding technology, allowing users to have MP3 audio on their movies. In 2001, original "developers" of
this hacked (and therefor illegal) codec released a new legal version of DivX ;-), called DivX (without smiley). DivX (without smiley) supports old DivX
;-) movies and also adds new features and better compression quality than "original" DivX ;-). The name, DivX ;-), comes from now defunct
CircuitCity pay-per-view DVD format called DIVX. With DivX ;-), you can store 50-120 minutes of relatively good quality video to one CD (740MB)
(==most of the movies can be stored in one CD, unlike in VCD or SVCD). Only negative aspect DivX ;-) has when it's compared to VCD is the fact
that VCDs can be played with regular stand-alone DVD players and DivXs can't.
DLP Digital Light Processing. A recent development in display technology by Texas Instruments which uses mirrors to display the image. Better than
LCD for video display, DLP is now used in most low to middle range projectors. DLP: Digital Light Processing. A Texas Instruments process of
projecting video images using a light source reflecting off of an array of tens of thousands of microscopic mirrors. Each mirror represents a pixel and
reflects light toward the lens for white and away from it for black, modulating in between for various shades of gray. Three-chip versions use separate
arrays for the red, green, and blue colors. Single-chip arrays use a color-filter wheel that alternates each filter color in front of the mirror array at
appropriate intervals.
DMCA Full description not available yet. An American legislation, called Digital Millennium Copyrights Act that outlaws distribution, sale, use
and advertising of tools that allow circumventing copy protection mechanisms. Legislation also includes various other amendments to existing
copyright legislation, such as "cease and desist" letter format for copyright holders when they wish to warn a website that hosts material on their site
that violates copyright holder's rights.
DMD: Digital Micromirror Device. Texas Instruments engine that powers DLP projectors. Uses an array with tens of thousands of microscopic mirrors
that reflect a light source toward or away from the lens, creating an image. Each mirror represents a pixel. See DLP.
DMV Digital Media Vision (company now called NDS broadcast)
DNG: "Digital news gathering." Electronic news gathering (ENG) using digital equipment.
DNR: Dynamic Noise Reduction. A signal-processing circuit that attempts to reduce the level of high-frequency noise. Unlike Dolby NR, DNR doesn't
require preprocessing during recording.
DOCSIS Data Over Cable Service Interface Specifications
Specification for transmission of data over a cable network that has been approved by the ITU as an international standard. DOCSIS was developed
by MCNS, a consortium consisting of CableLabs and a consortium of North American multi-system operators. Competes with the DVB standard in
Europe.
Dolby Full description not available yet. Private company that develops audio formats, mostly surround audio formats, such as AC3. Dolby ™ -An
audio compression/expansion system that produces signal-to-noise improvements in the sound quality of your footage, making audio far clearer.
]Dolby 5.1 Dolby digital full surround sound, front left and right, rear left and right and centre together with a sub-woofer for extra bass
Dolby B: A noise-reduction system that increases the level of high frequencies during recording and decreases them during playback.
Dolby C: An improvement on Dolby B that provides about twice as much noise reduction.
Dolby Digital (AC-3): The audio format standard for DVDs. Mono, stereo and surround sound tracks can all be encoded in Dolby Digital for highquality audio. Dolby Digital: An encoding system that digitally compresses up to 5.1 discrete channels of audio (left front, center, right front, left
surround, right surround, and LFE) into a single bitstream, which can be recorded onto a DVD, HDTV broadcast, or other form of digital media. When
RF-modulated, it was included on some laser discs, which requires an RF-demodulator before the signal can be decoded. Five channels are fullrange; the .1 channel is a band-limited LFE track. A Dolby Digital processor (found in most new receivers, preamps, and some DVD players) can
decode this signal back into the 5.1 separate channels. Most films since 1992's Batman Returns have been recorded in a 5.1 digital format, though a
number of films before that had 6-channel analog tracks that have been remastered into 5.1. Dolby Digital (formerly Dolby AC-3): The approved 5.1
channel (surround-sound) audio standard for ATSC digital television, using approximately 13:1 compression. Six discreet audio channels are used:
Left, Center, Right, Left Rear (or side), Right Rear (or side), and a subwoofer -- LFE, "low frequency effects" -- (considered the ".1" as it is limited in
bandwidth). Dolby DigitalDolby Digital (AC-3) is Dolby's third generation audio coding algorithm. It is a perceptual coding algorithm developed to
allow the use of lower data rates with a minimum of perceived degration of sound quality.This coder has been designed to take maximum advantage
of human auditory masking in that it divides the audio spectrum of each channel into narrow frequency bands of different sizes optimized with
respect to the frequency selectivity of human hearing. This makes it possible to sharply filter coding noise so that it is forced to stay very close in
frequency to the frequency components of the audio signal being coded. By reducing or eliminating coding noise wherever there are no audio signals
to mask it, the sound quality of the original signal can be subjectively preserved. In this key respect, a coding system like AC-3 is essentially a form
of very selective and powerful noise reduction. In the consumer electronics industry the Dolby Digital soundtrack can be found on the latest
generation of LaserDiscs (in space where one of the analog tracks used to be), can be found as the standard audio track on Digital Versatile Discs
(DVD), is the standard audio format for High Definition Television (HDTV), and is being used for digital cable and satellite transmissions. Dolby
Digital (formerly Dolby AC-3) - The approved 5.1 channel (surround-sound) audio standard for ATSC digital television, using approximately 13:1
compression. Six discreet audio channels are used: Left, Centre, Right, Left Rear (or side), Right Rear (or side), and a subwoofer -- LFE, "low
frequency effects" -- (considered the ".1" as it is limited in bandwidth).
Dolby Digital 5.1 (DD 5.1): The most common sound output for DVDs. DD 5.1 sends unique signals to six different speakers: front left, front center,
front right, rear left, rear right and subwoofer. To experience DD 5.1 you need a DVD player and/or a receiver than can decode the signal, or you
need a DVD player with a built-in decoder and a DD-ready receiver Dolby Digital (5.1) Dolby Digital is a form of digital audio coding which makes it
possible to store and transmit high quality digital sound. This audio coding can be used for mono, stereo or multi-channel soundtracks. Dolby Digital
5.1 is a multi-channel system used by film producers to deliver five discrete (ie the signals for each channel are recorded independently), full range
channels: front left, front right, front centre, left surround and right surround. The .1 refers to the Low Frequency Effects (LFE) channel which is
purely for bass and is therefore not full range.
Dolby E The preferred digital audio system for HDTV transmission, incorporating 8 channels (6 channels 5.1 and 2 channels stereo)
Dolby EX: An enhancement to Dolby Digital that adds a surround back channel to 5.1 soundtracks. The sixth channel is matrixed from the left and
right surround channels. Often referred to as 6.1. Sometimes referred to as 7.1 if the system uses two surround back speakers, even though both
speakers reproduce the same signal. Software is backwards-compatible with 5.1 systems, but requires an EX or 6.1 processor to obtain additional
benefit.
Dolby Pro-Logic: The VHS standard for delivering surround sound. All DD 5.1 receivers can decode Pro-Logic. Some older DVDs may be encoded
with digital Pro-Logic signals. Dolby Pro Logic: An enhancement of the Dolby Surround decoding process. Pro Logic decoders derive left, center,
right, and a mono surround channel from two-channel Dolby SurroundÐencoded material via matrix techniques.
Dolby Pro-Logic II Dolby's original Pro-Logic surround sound system developed in the 1980s used four channels - front left, front right, centre and a
mono rear. The rear channel's treble frequencies were also limited. Pro-Logic II is an enhanced version with full range stereo output and greatly
improved steering logic. It can be used with any kind of stereo programme - CDs, older film and TV material, games, etc - to give surround sound
effects. Dolby Pro Logic II: An enhanced version of Pro Logic. Adds improved decoding for two-channel, non-encoded soundtracks and music.
Dolby Surround (Dolby Stereo): Matrix analog coding of four audio channels - Left, Center, Right, Surround (LCRS) - into two channels referred to
as Right-total and Left-total. The Dolby Surround system originally was developed for motion pictures.
Dolby Surround EX: New sound format that sends unique signals to seven different speakers: Front left, front center, front right, rear left, rear
center, rear right, and subwoofer. To experience Dolby Surround EX (also called Dolby Digital 6.1) you need a receiver than can decode the signal,
or an add-on amplifier that can decode the extra rear center signal.
Dome: A type of speaker-driver shape; usually used for tweeters (convex). Concave domes are usually referred to as "inverted domes."
Dope: A tacky substance added to paper cones to damp spurious vibrations that can cause breakup and rough response. Also, see Editor.
Dot Crawl: An artifact of composite video signals that appears as a moving, zipper-like, vertical border between colors.
Down conversion The reproduction of an image in high definition to a standard definition image.
Downconverting: The process which changes the number of pixels and/or frame rate and/or scanning format used to represent an image, by
removing pixels. (See Upconverting.)
Downlink Transmission of signals from a satellite to a dish or earth station.
Downmixing: Occurs when audio or video information on a disc is being sent to equipment that doesn't have capabilities to reproduce it. A common
example of downmixing is when a Dolby Digital 5.1 track is sent to a stereo TV or Pro-Logic receiver. The audio will still sound great (better than
VHS) but it will lose some dynamic range in the process.
Downstream or Forward Traffic - Signals transmitted to a subscriber.
DPCM Differential Pulse Code Modulation
dpi Abbreviation for "Dots per Inch." Indicates the resolution of a printer, scanner, or monitor. Refers to the number of dots in a one-inch (approx.
25.4-mm) line. DPI "Dots Per Inch" DPI refers to the number of pixels in a 1 inch long line. Most commonly heard with reference to printers i.e.
600dpi = 360,000 dots per square inch.
DPOF: Digital Print Order Format allows the user to mark their recorded still images with printing instructions, such as which photos they want to
print and how many copies are required. This makes it easier to get prints made at a photo laboratory or to print them at home.
DRAM: "Dynamic Random Access Memory" (RAM). High density, cost-effective memory chips.
Driver: The actual speaker unit inside the speaker cabinet. There are three general types on drivers: tweeters, midrange, and woofers. Driver: A
speaker without an enclosure; also refers to the active element of a speaker system that creates compressions and rarefactions in the air.
DRM Digital Rights Management and it is now (spring 2002) the hot topic among content owners and technology companies alike. DRM doesn't
mean just basic copy-protection of digital content (like ebooks, MP3s or DivX videos), but it basically means full protection for digital content, ranging
from delivery to end user's ways to use the content. If we speak about music DRM, companies wish to develop a product which would allow record
labels to sell copy-protected audio tracks over the Internet, so that only the buyer could be allowed to listen the tracks. This is technically difficult,
because traditionally, national laws require content owners like record labels, to grant "fair use" rights for products consumers buy. This means that
user has to be allowed to make personal copies of the purchased music, in order to use the music in car, in portable digital audio player, in his/her
laptop computer, etc. So, somehow DRM system needs to know when the copying is allowed and when not -- users also have rights to make copies
to their closest relatives, etc. So, normally this has been solved by allowing "hops" --original file can be copied, but the copy of the original file cannot
be copied any further. Obviously this also causes problems, if user accidentally deletes the original file, but still has the legal copy of the file :-)
Drop The cable and hardware from tap to subscriber is called the drop.
Drop Cable Generally 100m or less, of coaxial cable, starting at a tap and continuing on to the subscriber's connection.
DSD: See Direct Stream Digital.
DSDL Double Sided Dual Layer DVD. For more information, see DVD-18.
DSML Double Sided Mixed Layer DVD. For more information, see DVD-14.
DSP: Digital Signal Processing. Manipulating an audio signal digitally to create various possible effects at the output. Often refers to artificially
generated surround effects derived from and applied to two-channel sources.
DSP Digital Signal Processor
DSSL Double Sided Single Layer DVD. For more information, see DVD-10.
DTB Digital Television Broadcasting
DTCPCG Digital Television Channel Planning Consultative Group
DTS: Digital Theater Systems. This is a competing audio format to Dolby Digital. Some DVDs have DTS tracks, but the compression rate is much
larger, so a DTS disc will hold less information. DTS: Digital Theater Systems. A digital sound recording format, originally developed for theatrical film
soundtracks, starting with Jurassic Park. Records 5.1 discrete channels of audio onto a handful of laser discs, CDs, and DVDs. Requires a player
with DTS output connected to a DTS processor. DTS Full description not available yet. DTS is a private company that develops audio formats, pretty
much like Dolby. With term "DTS" people generally speaking refer to DTS's digital surround audio technology that is used widely on DVD-Video
discs, just like Dolby's Dolby Digital/AC3.
DTS (5.1) Digital Theater Systems is an alternative digital audio coding system to Dolby Digital and offers high quality audio coding for digital movies,
music, TV broadcasts, games, etc. The data rate is much higher than Dolby Digital so in theory it should provide a superior sound.
DTS-ES: A competing audio format to Dolby Surround EX, DTS-ES sends unique signals to six different speakers: front left, front center, front right,
rear left, rear right and subwoofer. Like, Dolby Surround EX, you need decoding equipment to experience it. DTS ES: An enhanced version of the 5.1
DTS system. Like Dolby's Surround EX, a sixth channel is added. In some cases (DTS ES Discrete), the sixth channel is discrete. Software is
backwards-compatible with 5.1 systems, but requires an ES or 6.1 processor to obtain additional benefit. Neo:6 is a subset of DTS ES that creates
6.1 from material with fewer original channels.
DTT Digital Terrestrial Television
DTTB Digital Terrestrial Television Broadcasting
DTV: Digital Television. Umbrella term used for the ATSC system that will eventually replace our NTSC system in 2006. HDTV is a subset of the
DTV system. While the FCC does not recognize specific scan rates in the adopted DTV system, typically accepted rates include 480i, 480p, 720p,
and 1080i. DTV Digital Television DTV (DIGITAL TELEVISION): The umbrella term used for the new broadcasting system adopted by the FCC in
1996. DTV includes all elements of digital broadcasting, including High and Standard Definition television, datacasting and multicasting. Analog
television receives one continuous electronic signal. In contrast, DTV works on the same principle as a computer or a digitally recorded compact
disk. It uses binary code, a series of ones and zeros, rather than a continuous signal. DTV: "Digital television." This comprises all the components of
digital television, including HDTV, SDTV, datacasting, and multicasting. DTVDTV stands for Digital Television, which simply defines that the
broadcast signal is being transmitted in digital form (normally in either MPEG-2 or MPEG-1 format). The term itself doesn't define how the signal is
being transmitted or which resolution it should use. In "real life", Europe has chosen to use existing PAL resolution in digital broadcasting, but
Americans and most notably Japanese, have opted to use the "subset" of DTV, called HDTV in their broadcasts which offers native 16:9 aspect ratio
and higher video resolution. In Europe, three transmission standards are being used, DVB-T, DVB-C and DVB-S. DTV - Digital television.
D/U Desired to Undesired
Dual cable Two independent distribution systems operating side by side, providing double the channel capacity of a single cable.
Dual Scan Passive Matrix: Newer version of the original passive matrix technology, where the screen is controlled by two processing systems. A bit
faster than "single scan," response is still horrendously slow, they cannot do multimedia or video either. Contrast remains terrible. Dual scan is used
in the least expensive LCD panels.
Dub: A "dub" is a duplicate copy of an existing tape.
Duplex In a communications channel, the ability to transmit in both directions.
DVB Digital Video Broadcasting, suffixed S for satellite, C for cable, T for terrestrial, CS for SMATV, TXT for fixed-format teletext and MS for
MMDS. DVB Digital Video Broadcasting Project is an industry organization that develops technologies for the digital TV. The three most widely used
DVB's transmission protocols are DVB-C, DVB-S and DVB-T. All of these digital platforms are widely used, although mostly in Europe. DVB
developes not just transmission protocols, but also interactive standards for digital TV set-top boxes, etc. Various other DVB's protocols include MHP
(multimedia home platform, also dubbed as DVB-MHP), DVB-M (standard for measuring DVB-S/T/C transmissions, etc), DVB-H (an "upgrade" of
DVB-T standard that would allow using terrestial network to deliver DVB-T digital stream to mobile devices), etc. DVB's homepage is here.
DVB-C Full description not available yet. DVB-C is an acronym for Digital Video Broadcasting - Cable and means basically the (mostly used in
Europe) digital TV broadcasting method that's done via digital cable networks. Other digital TV broadcasting technologies developed by the DVB
Project are DVB-T and DVB-S.
DVB-H stands for Digital Video Broadcasting: Handhelds and is basically an extenstion to older DVB-T standard. DVB-H is a terrestial digital TV
standard that uses less power in receiving client than its big brother, DVB-T, and allows the receiving device to move freely while receiving the
transmission, thus making it ideal for mobile phones and haldheld computers to receive digital TV broadcasting over the digiTV network (without
using mobile phone networks at all). As it is really just an extension to DVB-T, DVB-H uses the same specs as its older brother. Video is normally
encoded with MPEG-2 (but can be encoded with MPEG-1 as well, although very rarely used) and the standard, just like its other siblings DVB-C,
DVB-S and DVB-T, is mostly used in Europe.
DVB-H was formerly known as DVB-X.
DVB-S Full description not available yet.DVB-S is an acronym for Digital Video Broadcasting - Satellite and means basically the (mostly used in
Europe) digital TV broadcasting method that's done via satellite (other digital TV broadcasting technologies developed by the DVB Project are DVB-T
and DVB-C).
DVB-T Full description not available yet. DVB-T is an acronym for Digital Video Broadcasting - Terrestial and means basically the (mostly used in
Europe) digital TV broadcasting method that's done via terrestial networks -- normally existing analogue TV antennas are used to receive the
transmissions. Other digital TV broadcasting technologies developed by the DVB Project are DVB-S and DVB-C.
DVC Digital Video Cassette
DVCD Double VideoCD -- pretty popular format in mainland China. Format itself is nothing new really, its just a regular VideoCD overburned to
include 90 to 99mins per CD, compared to regular 74mins per CD in standard VideoCD format.
DVD: Acronym for Digital Video Disc or Digital Versatile Disc. The disc is the same size as an audio CD but can hold hours of video and audio, as
well as other information and alternative versions. DVD Digital Video Disk DVD "Digital Video Disk" A new generation of optical storage media with
several times the capacity of CD's. DVD: Officially known as the Digital Video Disc, though marketers unofficially refer to it as the Digital Versatile
Disc. DVD uses a 5-inch disc with anywhere from 4.5 Gb (single layer, single-sided) to 17 Gb storage capacity (double-layer, double sided). It uses
MPEG2 compression to encode 720:480p resolution, full-motion video and Dolby Digital to encode 5.1 channels of discrete audio. The disc can also
contain PCM, DTS, and MPEG audio soundtracks and numerous other features. An audio-only version, DVD-A uses MLP to encode six channels of
24-bit/96-kHz audio. DVD: "Digital Versatile Disk." (Formerly Digital Video Disk.) Same size as a CD but stores seven times CD capacity on a single
side. DVDs can also be double-sided or dual layer. Today most DVDs are used to display full-length commercial motion pictures, plus additional
material such as outtakes, director's notes, movie trailers, etc. DVD DVD stands for Digital Versatile Disc. It is very often used as a replacement
acronym for DVD-Video, which is one standard based on DVD format.If you want to read more, try these links: DVD-Video DVD-Audio DVD Footage is recorded using MPEG-2, and produces high quality footage, which can be quickly transferred over devices.
DVD-5 is an acronym that means a DVD disc that is one-sided single-layer disc and can contain upto 4.38 gigabytes of data on it. DVD disc
manufacturers love to use marketing terms and sell their discs as 4.7GB discs, but this is not true -- the 4.7GB is calculated by using so-called
"Japanese gigabytes", where the power of calculations is 1,000 instead of 1,024 (and 1.024 is the correct way to calculate everything in computer
world -- so, 1024 megabytes == 1 gigabyte). DVD-5 DVD-Video discs are nice, because DVD writers (this applies to both, DVD-R and DVD+R
standards) can only write single layer discs. Other regular DVD size acronyms are: -DVD-9 -DVD-10 -DVD 14 DVD-18
DVD-9 One form of DVD discs that means a single-sided dual-layer DVD disc. DVD-9 can hold approximately 7.95 gigabytes of data, even though
marketers like to use the 8.5GB value instead, but this is misleading and is calculated by using so-called "Japanese gigabytes" which means that
gigabyte is calculated as 1,000 megabytes, but in real computer terminology, gigabyte is 1,024 megabytes. DVD-9 DVD-Video discs are problematic
for DVD-R owners, because writable DVD discs can only hold the same amount of data that DVD-5 discs contain, due technical reasons. Other
regular DVD size acronyms are: -DVD-5 -DVD-10 -DVD-14 -DVD-18
DVD-10 means a two-sided DVD disc that hold single data layer on both sides.Effectively this means that DVD-10 is a dual-sided DVD-5 and can
hold 8.75 gigabytes of data with 4.38 gigabytes on each side. Two-sided discs need to be flipped over in order to access the other data side.
Unfortunately many blank DVD media advertisers mislead customers to believe that these discs are actually blank DVD-9 discs in hope that they
could copy their dual-layer discs directly to blank discs. But as dual-layer writable blank media is impossible to create, customers get misled. Other
regular DVD size acronyms are: -DVD-5 -DVD-9 -DVD-14 DVD-18 DVD-14
DVD-14 is an oddball format that doesn't really exist anymore, but was used for a short period of time back in late 1990s and in early years of new
millennium when manufacturing of DVD-18 discs was complicated and expensive. DVD-14 is a two-sided DVD disc that has one side which contains
single layer of data and one side which contains two layers of data. In easier terms, the other side of the disc is DVD-5 and the other side of the disc
is DVD-9.DVD-14 disc can hold upto 12.33 gigabytes of data. Other regular DVD size acronyms are: -DVD-5 -DVD-9 -DVD-10 DVD-18
DVD-18 in an acronym that means a two-sided DVD disc with two layers of data on both sides of the disc -- in other terms, it is a two-sided disc that
holds DVD-9 disc on both sides of it.DVD-18 disc can contain upto 15.9 gigabytes of data on it (with 7.95 gigabytes on each side). Other regular
DVD size acronyms are: -DVD-5 -DVD-9 -DVD-10 -DVD-14
DVD-A: Digital Versatile Disc-Audio. Enhanced audio format with up to six channels of high-resolution, 24-bit/96-kHz audio encoded onto a DVD,
usually using MLP lossless encoding. Requires a DVD-A player and a controller with 6-channel inputs (or a proprietary digital link) for full
compatibility. DVD Audio: Audio format that is similar to CD but with a higher sampling rate. This format has yet to catch on in the music industry.
DVD-Audio DVD is capable of holding far more digital data than a CD. This data can include audio as well as video signals. DVD-Audio is the next
generation audio format and can carry extremely high quality music. DVD-Audio can reproduce frequencies up to 192kHz - that's nearly five times
higher than the average person can hear and while these ultra high frequency components are beyond our audible range they play a key part in
conveying delicate musical nuances, venue ambience and soundstage imaging. In order to take advantage of music on DVD-Audio, you need a
compatible DVD player. DVD-Audio Full description not available yet. DVD-Audio is one of the standards controlled by DVD Forum, an authority
behind various DVD standards. DVD-Audio is music disc, aimed to replace regular audio CD within next few years. DVD-Audio disc can contain 4 18 GBs of data, depending on how many layers and sides of the disc are used. Regular DVD-Audio disc contains various copy-protection methods
and obviously the audio data itself -- audio can be stored in various formats, including uncompressed (L)PCM format (in frequencies from 44.1kHz
upto 192kHz) with bitrates as high as 9.8Mbit/sec. Other formats allowed include Dolby Digital 5.1, MPEG-1 (stereo, audio layers II and III), MPEG-2
(multichannel), DTS and SDDS.Another variety of DVD-Audio is called DVD-AudioV which adds a possibility to have regular DVD-Video compliant
video on the disc as well. DVD-Audio discs can't be played with regular DVD-Video players -- the player has to be so-called "Universal DVD" player
in order to support DVD-Audio (obviously if your player has DVD-Audio logo, it supports these discs).
DVD-Audio Ready DVD-Audio demands a high frequency range from both amplifier and speakers. DVD-Audio ready components are equiped to
offer the wider frequency response and better signal to noise ratio required of the format
DVD+R: A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Sony, Philips, Yamaha, HP, and others. DVD+R Full
description not available yet. A propietary recordable DVD format, developed by DVD+RW Alliance. Format currently (10/2003) allows single-layer
data to be stored on each side of the disc -- in other words, one side of the disc can hold upto 4.38 gigabytes of information (NOT 4.7GB what the
disc labels claim -- 4.7GB is achieved by tweaking the numbers and using 1,000 in calculations between megabyte and gigabyte, when the correct
number to be used should be 1,024). Dual-layer discs that can hold 8.5GB entered the market in Q2/2004. However, dual-layer discs can't be burned
using the old DVD+R writers that support only single-layer burning (==all DVD+R capable burners made before 2004 or so). Single layer discs pose
a problem when backing up pressed DVD-Video discs that can hold dual-layer worth of data per side, 8.5GB. Those discs need to be split to two
DVD+R discs if all the information has to be preserved from the original disc. DVD+R is technically slightly more advanced than its competitor, DVD-
R, but DVD-R still leads DVD+R by rather wide margin in terms of blank media sales. Both, DVD+R and DVD-R, formats are write-once formats.
DVD+R's "sister format" is called DVD+RW which is essentially a re-writable version of DVD+R. DVD-R's sister format is called DVD-RW. All most
common recordable DVD formats, DVD+R, DVD+RW, DVD-R and DVD-RW can be read with most stand-alone DVD players and with virtually all
DVD-ROM drives.
DVD-R: A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Pioneer, Panasonic, Toshiba, and others. DVD-R Full
description not available yet. A DVD Forum (the industry body that controls the development of DVD formats) approved recordable DVD format.
Format allows single-layer data to be stored on each side of the disc -- in other words, one side of the disc can hold upto 4.38 gigabytes of
information (NOT 4.7GB what the disc labels claim -- 4.7GB is achieved by tweaking the numbers and using 1,000 in calculations between megabyte
and gigabyte, when the correct number to be used should be 1,024). This poses a problem when backing up pressed DVD-Video discs that can hold
dual-layer worth of data per side, 8.5GB. Those discs need to be split to two DVD-R discs if all the information has to be preserved from the original
disc. Dual-layer DVD recordables entered the markets in Q2/2004. DVD-R is technically slightly less advanced than its competitor, DVD+R. But the
year 2002's projections of blank media sales show that sales of DVD-R media will exceed 90,000,000 discs during 2002 while sales of DVD+R
media will be only 13,000,000. Both, DVD-R and DVD+R, formats are write-once formats. DVD-R's "sister format" is called DVD-RW which is
essentially a re-writable version of DVD-R. DVD+R's sister format is called DVD+RW. DVD-R discs can be read with virtually any PC DVD-ROM
drive and with most of the regular, stand-alone DVD players.
DVD-RAM: A recordable DVD format similar to DVD-RW in that it is a re-writeable format. Unlike DVD-RW it is capable of being written to and
erased over 100,000 times. Backed by Hitachi, Panasonic, Toshiba, and others. DVD-RAMFull description not available yet. One of the competing
recordable DVD standards. Not compliant with regular stand-alone DVD-Video players and not compliant with any DVD-ROM drives either. Normally
used as a slow harddrive replacement. Standard is going to die pretty soon as more compatible standards, such as DVD-R and DVD+RW, are
getting more popular.DVD-RAM disc If you want to record using a VCR, you use videocassette. To record using a DVD-RAM recorder you need a
blank DVD-RAM disc. Two types are currently available from Panasonic - a 4.7 gigabyte disc which offers 120 minutes of record time and a doublesided 9.4 gigabyte version offering 240 minutes. Of course, with Panasonic's new hard disk recorder you needn't use any type of disc to record.
DVD-Rip Bootlegged movie copy made directly from a DVD-Video disc and encoded into some other format, like SVCD or DivX.
DVD+RW Full description not available yet. A propietary re-writable DVD format, developed by DVD+RW Alliance. Format allows single-layer
data to be stored on each side of the disc -- in other words, one side of the disc can hold upto 4.38 gigabytes of information (NOT 4.7GB what the
disc labels claim -- 4.7GB is achieved by tweaking the numbers and using 1,000 in calculations between megabyte and gigabyte, when the correct
number to be used should be 1,024). Dual-layer discs that could hold 8.5GB don't exist and most likely never will due technical limitations. This
poses a problem when backing up pressed DVD-Video discs that can hold dual-layer worth of data per side, 8.5GB. Those discs need to be split to
two DVD+RW discs if all the information has to be preserved from the original disc.DVD+RW is technically slightly more advanced than its
competitor, DVD-RW. But the year 2002's projections of blank media sales show that sales of DVD-RW dominate the rewritable market by ratio of
75-to-25 when compared to DVD+RW. Both, DVD+RW and DVD-RW, formats are re-writable formats. DVD+RW's "sister format" is called DVD+R
which is essentially a record-only-once version of DVD+R. DVD-RW's sister format is called DVD-R. DVD+RW: A recordable DVD format similar to
CD-RW in that it is re-recordable medium. Backed by Sony, Philips, Yamaha, HP, and others.
DVD-RW: A recordable DVD format similar to CD-RW in that it is re-recordable medium. Backed by Pioneer, Panasonic, Toshiba, and others. DVDRW. Full description not available yet. A DVD Forum (the industry body that controls the development of DVD formats) approved re-writable DVD
format. Format allows single-layer data to be stored on each side of the disc -- in other words, one side of the disc can hold upto 4.38 gigabytes of
information (NOT 4.7GB what the disc labels claim -- 4.7GB is achieved by tweaking the numbers and using 1,000 in calculations between megabyte
and gigabyte, when the correct number to be used should be 1,024). Dual-layer discs that could hold 8.5GB don't exist and most likely never will due
technical limitations. This poses a problem when backing up pressed DVD-Video discs that can hold dual-layer worth of data per side, 8.5GB. Those
discs need to be split to two DVD-RW discs if all the information has to be preserved from the original disc. DVD-RW is technically slightly less
advanced than its competitor, DVD+RW. But the year 2002's projections of blank media sales show that sales of DVD-RW media will dominate the
markets with appx. 75 percent re-writable market share. Both, DVD-RW and DVD+RW, formats are re-writable formats. DVD-RW's "sister format" is
called DVD-RW which is essentially a record-once version of DVD-R. DVD+RW's sister format is called DVD+R. DVD-RW discs can be read with
virtually any PC DVD-ROM drive and with most of the regular, stand-alone DVD players.
DVD-SVCD A term that means a hacked, non-standard DVD-Video disc that has SVCD-compatible content on it. Because DVD-Video specs don't
allow using the SVCD resolution (480x480 / 576) , SVCD material is basically impossible to transfer to a DVD-Video disc without re-encoding the
material and therefor lowering the quality. But some people have found a way to "hack" their way beyond this limitation. This process basically
involves modifying the SVCD's MPEG-2 headers so that the material stays the same, but the MPEG-2 header lies about the resolution and claims
that it is the same as in CVD (352x480/576 -- which IS one of the specified DVD-Video resolutions) resolution. This "trick" allows importing SVCD
material into DVD authoring tools and burning the SVCD material on recordable DVD media. The problem is that some, more accurate, DVD players
refuse to play such discs, because they're not within the DVD standards.
DVD-VCD. Actually a very misleading term, since DVD-Video specs clearly state that VCD-encoded video content is perfectly within the specs of
DVD-Video as well (with the exception of audio, which in VCD is 44.1kHz and in DVD 48kHz). But basically, DVD-VCD, is just a "clever" way to
stating that we're speaking of DVD-Video disc that has material on it which has been encoded by using MPEG-1 video format with same definitions
as VCD has (same resolution, same bitrate, etc). If you're interested of transferring your existing VCD movies to a DVD format, this process is
relatively painless -- as stated before, only real difference between VCD and one of the allowed DVD-Video specs is the fact that the audio frequency
needs to be changed from VCD's 44.1kHz to DVD-Video's 48kHz. Read our guide on how to do this.
DVD-Video Full description not available yet. Subset of DVD specs, even though normally term "DVD" refers to this particular format. DVD-Video
is a standard developed by DVD Forum and specifies how video should be stored on optical DVD disc. DVD-Video specs allow two different kind of
video encoding algorithms to be used: MPEG-2 and MPEG-1. Virtually all DVD-Video discs use MPEG-2 format, mostly because of its superiority
over MPEG-1 in terms of video quality. Resolutions that video streams can use, are:
720x480 (NTSC, only with MPEG-2) 720x576 (PAL, only with MPEG-2) 704x480 (NTSC, only with MPEG-2) 704x576 (PAL, only with MPEG-2)
352x480 (NTSC, MPEG-2 & MPEG-1) 352x576 (PAL, MPEG-2 & MPEG-1) 352x240 (NTSC, MPEG-2 & MPEG-1) 352x288 (PAL, MPEG-2 &
MPEG-1)
D-VHS: Digital VHS. Digital signals recorded onto magnetic tape. Greater capacity than typical VHS; can record compressed HDTV signals. See DTheater
DVI Digital Video Interface. A standard created by the Digital Display Working Group (DDWG) to enable analogue and digital display devices to be
used with a single connection cable and to allow the video signals to be sent to the display device digitally. By transmitting the signal digitally there is
none of the quality degradation associated with the analog to digital and back again conversion. So, if you have a source device with DVI and a
display with DVI then everything can remain within the digital realm. DVI: Digital Visual Interface. Connection standard developed by Intel for
connecting computers to digital monitors such as flat panels and DLP projectors. A consumer electronics version, not necessarily compatible with the
PC version, is used as a connection standard for HDTV tuners and displays. Transmits an uncompressed digital signal to the display. The latter
version uses HDCP copy protection to prevent unauthorized copying. See also HDMI. DVI: DVI means Digital Visual Interface. DVI is a standard that
defines the digital interface between digital devices such as projectors and personal computers. For devices that support DVI, a digital to digital
connection can be made that eliminates the conversion to analog and thereby delivers an unblemished image. Specifications on DVI are available at
www.ddwg.org. DVI DVI, Digital Video Interface, is a specification created by the Digital Display Working Group (DDWG). The DVI specification
has created an uniform connector that can accommodate both, digital and analog video signal. DVI has three subsets: DVI-A, for analog signals,
DVI-D, for digital signals, and DVI-I (integrated), for both analog and digital signals. DVI - Intel Corporation’s Digital Video Interactive allows the
recording of 72 minutes of full-motion video, 40-hours of digital audio, or a combination of both audio and video on a CD-ROM disc. The video quality
is said to rival that of VHS 1/2-inch videotape.
DVI-A Description not available yet, for more information, see DVI instead.
DVI-D Description not available yet, for more information, see DVI instead.
DVI-I DVI-I stands for Digital Video Interface - Integrated and means a DVI connector that can transmit both analog and digital video data.
DVTR: "Digital videotape recorder."
Dynamic Range Dynamic range describes the ratio of the softest sound to the loudest sound in a musical instrument or piece of electronic
equipment. This ratio is measured in decibels (abbreviated as dB) units. Dynamic range measurements are used in audio equipment to indicate a
component's maximum output signal and to rate a system's noise floor. As a reference point, the dynamic range of human hearing, the difference
between the softest sound we can perceive and the loudest, is about 120 dB. Compressors, expanders, and noise gates are processing devices that
are used in audio to alter the dynamic range of a given signal. This is done to achieve a more consistent sound when recording or as a special effect
(by radically altering the dynamics of a sound, thereby creating a sound not possible from the original source). Dynamic Range: The difference
between the lowest and the highest levels; in audio, it's often expressed in decibels. In video, it's listed as the contrast ratio.
E
Earth Station The antennas and other equipment needed on the ground to transmit or receive satellite communication signals.
Easter Egg: A hidden, special feature on DVD only savvy users can discover. It's usually a documentary, hidden audio track, theatrical trailer or TV
trailer.
EBU European Broadcasting Union
e-Cinema see Electronic Cinema
EDGE Description not available yet.
EDTV: Extended Definition Television. This CEA-adopted term (though originally mentioned in an April '99 HT article by Mike Wood and Mike
McGann) is defined as those products that can display DTV images as 480p or higher. EDTV Enhanced Definition Television
Education Access Channel A cable television channel specifically designated for use by local education authorities in the US.
Efficiency Rating: Level of sound output measured at a prescribed distance with a standard input power. Efficiency rating standard is 1 watt (2.83V
at 8 ohms) at 1 meter over a specified frequency range and is measured in decibels.
EIA: "Electronics Industries Association."
EIT Event Information Table (part of SI)
Electronic Cinema Digital theatrical projection by replacing the film distribution network with data.
Electronic Programming Guide (EPG): An application that provides an on-screen listing of all programming and content that an interactive
television service subscriber or digital television viewer has available to them.
Electrostatic: One of the oldest speaker design principles, electrostatic speakers are generally comprised of two fixed perforated panels with a
constant high-voltage charge applied to them. In between these two panels is an extremely low-mass diaphragm to which the audio signal is applied,
causing it to move. There are variations on this construction, but all electrostatic speakers are free from the magnets and voice coils used in
conventional speakers.
ELG European Launching Group
Enclosure: The container of air that surrounds the rear of a speaker driver.
Encode Full description not available yet. Encoding is opposite of decoding. Encoding means that a file, whether it is an audio, video or picture
file, is compressed to another format that normally takes up less physical drive space than the previous format. Common video encoding methods
are DivX, MPEG-1, MPEG-2 and MPEG-4 -- most common audio encoding method or format is MP3.
Encryption: The process of coding data so that a specific code or key is required to restore the original data, used to make transmissions secure
from unauthorized reception.
End user A person, organisation, or telecommunications system that accesses the network to communicate via the services provided by the
network.
Enhanced for 16:9: See Anamorphic.
Enhanced for Widescreen: See Anamorphic.
ENHANCED TELEVISON: (Also known as Interactive Television) The term used for certain digital on-air programming (usually educational) that
includes additional resources viewers can download. The system will allow viewers to simultaneously watch an enhanced television program while
downloading additional video, audio, text and data related to the program. Currently, the system is still based on broadcast technology, so users who
wish to interact with the content provider must have a "back channel" i.e. a telephone or computer modem.
Enhanced TV: Term used by PBS for certain digital on-air programming (usually educational) that includes additional resources downloaded to
viewers. Some forms of enhanced TV allow live interaction; other forms are not visible on-screen until later recalled by viewers. Also known as
"datacasting."
Enhancements: Producers add these options to some digital programming to enhance program material -- allowing viewers the ability to download
related program resources to specially equipped computers, cache boxes, set-top boxes, or DTV receivers.
EPG Electronic Programme Guide ELECTRONIC PROGRAMMING GUIDE (EPG): How you select channels on a digital television. This menubased screen will help the viewer navigate the channels available in much the same way that small dish satellites do today. The EPG will allow the
viewer to display choices in a variety of ways, such as by genre or other category. Ultimately, the EPG will enable the television to "learn" the viewing
habits of its user and suggest viewing schedules.
EP Mode Extended Play mode featured on a Panasonic DVD-RAM recorder. Can offer up to 12 hours of record time when used with a 4.7 gigabyte
blank disc.
EPROM Erasable Programmable Read Only Memory
EPS "Encapsulated PostScript". A file which contains a complete definition of an image ready to be output to a "PostScript" enabled device. Used
extensively in the publishing and printing industries
Errored second Any one-second interval containing at least one bit error.
EQ: See Equalization or Equalizer ERP Effective Radiated Power
Equalization: Loosely, any type of relative frequency adjustment. Specifically, the process of changing the frequency balance of an electrical signal
to alter the acoustical output.
Equalizer: A component designed to alter the frequency balance of an audio signal. Equalizers may be graphic, parametric, or a combination of
both.
Ethernet The most popular LAN technology in use today. The IEEE standard 802.3 defines the rules for configuring an Ethernet network. It is a 10
Mbps, CSMA/CD baseband network that runs over thin coax, thick coax, twisted pair or fibre optic cable.
ETS European Telecommunication Standard
ETSI European Telecommunication Standards Institute
EX: See Dolby EX.
EX Surround Films with Dolby Digital EX Surround have a third rear channel for more realistic effects: you get a better spread of sound behind you
and this adds more realism. To take advantage of this 'back surround channel' you need a compatible processor and an extra speaker which is
placed between the two at the back. DTS also has its version of EX called DTS-ES.
Extended subplot A frequency division scheme that allows bi-directional traffic on a single cable. Reverse path signals come to the headend from
a 5 to 45 MHz. Forward path signals go to the headend from 54 to the upper frequency limit.
External Crossover: A standalone unit. See crossover.
EZ-D is a new DVD-Video-compatible optical disc developed by a company called Flexplay. They're (or should be -- currently, 09/2003, there are
no official reports on discs' compatibility issues) fully compatible with DVD-Video specs, but differ from traditional DVD-Video discs because their dye
is made in such way that once opened from airtight container, discs will turn into black within 48hrs and become unreadable by DVD players. Thus,
discs are being called as disposable DVDs. Currently (09/2003) Disney is running trials with these discs
F
F-Connector The final piece of hardware to subscribers on a drop cable. It is cylindrical with a centre pin sticking out, that plugs into the set-top
box, cable ready TV or VCR.
Factory Alignment Refers to the bench test alignment conditions with the slope and gain controls (where applicable) turned to maximum and no
pad or equaliser installed. These specs can be used to verify operation during a bench test.
FACTS Federation of Australian Commercial Television Stations
Fader: The control on a projector, that allows you to control the balance of sound between the projectors internal speakers and the external
speakers (PA, powered speakers). Only a couple of projectors offer this convenient feature.
Fastext – Commonly understood as the four coloured buttons used when in the ceefax/teletext mode. The red,green,yellow and blue buttons allow
the user to’jump’ to certain stored pages.. have already been adapted by digital tv broadcasters for use with differing commands depending on the
product. FASTEXT The free information data service supplied by TV companies. Also known as Teletext and Ceefax.
FastTrack Full description not available yet. A decentralized P2P network that powers P2P applications such as Kazaa, Grokster and (at least
partially as of now, Oct/2003) iMesh. Used to be the backbone of Morpheus as well, but Morpheus switched to use Gnutella network instead in
beginning of 2002.
FCC Federal Communications Commission
FEC Forward Error Correction
Feedback: The transmission of current or voltage from the output of a device back to the input, where it interacts with the input signal to modify
operation of the device. Feedback is positive when it's in phase with the input and negative when it's out of phase.
Feeder Cables
The cables that take signals from the trunk line to the subscriber area and to which the subscriber taps are attached.
Feeder line Cable distribution lines that connect the main trunk line or cable to the smaller drop.
FFT Fast Fourier Transform
Fibre Distributed Digital Interface (FDDI) A network based on the use of optical fibre to transmit data at a rate of 100 Mb/s.
Fiber optics: Thin glass filaments within a jacket or bundle that optically transmit images or signals in the form of light over distances, with extremely
low high-bandwidth quality losses. Fiber Optic Cable: Glass, plastic, or hybrid fiber cable that transmits digital signals as light pulses. Fiber Optic
Cable: A small, light cable transmitting light pulses that translate to TV. Fibre optics Very thin and pliable tubes of glass or plastic used to carry
wide bands of frequencies transmitting signals over light waves.
Field: One of the two equal but vertically separated parts into which a television frame is divided in an interlaced system of scanning. A period of
1/60 second separates each field start time.
Field Effect Transistor (FET) A low amplifying device available in many different forms including gallium arsenide. Ideal for use in high-gain, lownoise amplifier circuits, especially at ultra-high and microwave frequencies.
Film Artefacts Film artefacts are defects in the origional film source. The can most easily be seen in older films where you can often see marks
where they should not be (black spots on skylines and such like.
Film lenses versus electronic lenses
The physics or the back focal length to the image capture surface i.e. film frame or CCD chip is different.
Filter A passive or active frequency selective circuit designed to modify a signal or source of power.
FireWire: See IEEE 1394. FireWire Popular interface standard for connecting PCs and peripheral devices. Allows 400-Mbps high-speed data
transfer. "FireWire" is the name used by Apple Corporation and is identical to IEEE1394. It is also called "i.Link." Fire Wire: A low-cost digital
interface originated by Apple Computer and further developed by engineers and adopted by CEMA. It can transport data at 100, 200, or 400 Mbps.
This is widely viewed as one key solution to connect digital-related TV components with each other. Also known as IEEE-1394. FireWire Full
description not available yet. FireWire is a friendlier, "marketing" name for technology known as IEEE.1394. FireWire is basically a competitor to USB
technology, beating the original USB1.x hands down in transfer speeds, etc. FireWire is widely used in Apple computers and also virtually all of the
digital camcorders are equipped with FireWire ports. The technology is currently (03/2003) getting more and more popular in Intel-based PCs as
well.
Firmware Full description not available yet. Sort of a "operating system of the hardware", an embedded instruction set built-in or flashed into a
hardware equipment, such as a router, CDR drive, DVD-ROM drive, washing machine, etc.
Fixed Data Rate Compression: Techniques designed to produce a data stream with a constant data rate.
FLAC Free Lossless Audio Codec. Lossless means that the audio is compressed, but the quality of the input audio wont suffer from the
compression, but remains identical. This is exactly unlike the audio formats such as MP3 and WMA work -- these audio formats are called "lossy"
and that means that when the original audio is encoded into the lossy audio format, some of the audio data is lost forever and can't be brought back
by any means. So, to summarize, by encoding audio files with FLAC, the quality is exactly the same as the original audio file's quality is.
Flatness (dB) difference in maximum and minimum gain within a certain frequency range
Flat Screen Display - Television screens that flatten the size of the sets to that of a framed picture. The screens on today's sets use bulky cathode
ray tubes (CRTs). CRTs are made of a glass envelope and use a controlled beam of electrons striking light-emitting material to display the picture.
Flat screen displays use plasma display systems that do not require the use of CRTs and other bulky tube equipment.
Flippers: Slang term for a DVD on which a film is split on two sides. Some longer films released on early DVDs are flippers, but the advent of better
compression technology and RSDL discs eliminated the need for these. See also layer change, RSDL, and compression.
FM: Frequency Modulated.(tion)
FM Based Remote: A remote control that broadcasts its instructions with an FM transmitter, normally required in large rooms, thanks to long range,
and no line of site requirement.
FM Broadcast Band The band of frequencies extending from 88 to 109 MHz
FM Cable system FM radio signals offered by the cable system (the cable must be connected to the subscriber's FM stereo receiver.)
Focal Length: The distance from the surface of a lens to its focal point.
Focus The focusing range of projector lenses is what defines the minimum and maximum projection distances.
Foot Lamberts A measurement of reflected light off a surface. To work out foot lamberts, take the light output of your projector and divide by your
screen size measured in square feet then multiply by the screen gain. In a well set up home cinema room, with no ambient light an reflectance of 1222 foot lamberts is ideal, however in most home cinema rooms which double up as the family sitting room a higher output will be required as it is
difficult to achieve complete darkness. In this situation aim for around 30 foot lamberts which will be fine for watching films in relative darkness.
FORMAT: The various standards used to broadcast DTV. Currently, there are several formats used to broadcast both standard and high definition
programs. You may hear terms like 480i, 720i and 1080i. These are digital formats.
Format Conversion: Process of both encoding/decoding and re-sampling digital rates to change digital data from one format to another.
Form Factor: A general discription a major feature or features that identify a type of projector or catagory of capabilities. Example: The Epson's form
factor is considered the classic road warrior machine; weight under 17 lbs, zoom lens for easy placeme nt, enough brightness to handle a darkened
auditorium, and small enough to be moved easily and qualify as carry-on luggage, even in its hard case.
Forward Error Correction (FEC) FEC enables the receiver to detect and fix errors to packets without the need for the transmitter to retransmit
packets.
Forward Traffic also Downstream or forward channel - Signals transmitted to a subscriber from the headend.
FourCC, a four character code in beginning of media file, mostly associated with AVI, that tells what codec your system should use for decoding the
file.Method was implemented originally by Electronic Arts back in 80s for Amiga's IFF file format which was an universal multimedia file format that
supported audio, video and pictures within same wrapper format. Later this was copied to Apple's AIFF format and Microsoft's RIFF format. For an
excellent list of recognized FourCC codes, please visit this website.
Fps See framerate fps - "Frames Per Second," the number of still frames (pictures) that give the illusion of motion, which appear in a single second
of time.
Fragmentation: Scattering of data over a hard disk caused by successive recording and deletion operations. Generally this will eventually result in
slow data recall - a situation not suitable for video recording or replay. Fragmentation When broad television audiences break into smaller
segments due to multiple viewing choices and niche programming that targets particular demographics.
Frame - A complete, individual picture on a motion-picture film or contained in a video signal.
Frame rate The number of complete images per second. FramerateDefines how many pictures eg. frames one second of video or audio contains,
normally used acronym for framerate is fps - frames per second. Human eye can't see picture changes after the framerate is more than ~24fps.In
American TV system NTSC the framerate is appx. 29.97fps and in European PAL system the framerate is 25fps.
Franchise A contract between a cable television company and a municipal government authorising the company to install cable and offer cable
television service within the specified area.
Freeze frame: Display of a single (frozen) frame of video.
Frequency: The number of cycles (vibrations) per second. In audio, audible frequencies commonly range from 20 to 20,000 cycles per second (Hz).
In video, frequency is used to define the image resolution. Low-frequency video images depict large objects or images. Higher frequencies depict
smaller objects (finer details). Frequency The number of times a complete electromagnetic wave cycle occurs in a fixed unit of time, usually one
second. The rate at which a current alternates, measured in Hertz on a telecommunications medium.
Frequency Modulation (FM) A common method of transmitting information over a carrier wave by changing its frequency.Frequency Response:
A measure of what frequencies can be reproduced and how accurately they are reproduced. A measurement of 20 to 20,000 Hz ± 3dB means those
frequencies between 20 and 20,000 Hz can be reproduced no more than 3 dB above or below a reference frequency level. Frequency response
variations of the gain of a certain device within a frequency range
Front End The first radio-frequency amplifier stage in a receiver. This is one of the most critical components of the receiver because because the
sensitivity of the front end dictates the sensitivity of the entire receiver.
Front Room Projector or Position: A unit that sits close to the screen, its short throw lens projects an image size that is about the same as the
distance to the screen. 6FT diag. screen = 6FT distance. Generally the unit might be as close as 3/4 the screen size or as far as 1.2 times image
size.
F-stops The aperture (diaphragm) of a lens.
Full-Duplex Independent, simultaneous two-way transmission in both directions, as opposed to half-duplex transmission.
Full-motion video - A standard for video playback on a computer; it refers to smooth-flowing, full-colour video, similar to a VCR or television. Also
known as full-screen, full or true-colour, or full-motion video. Full-Motion Video Not compressed; a standard video signal of 30 frames per second,
525 horizontal lines per frame, capable of complete action.
Full On/Off Contrast: Contrast is the ratio between white and black. The larger the contrast ratio the greater the ability of a projector to show subtle
color details and tolerate extraneous room light. There are two methods used by the projection industry: 1) Full On/Off contrast measures the ratio of
the light output of an all white image (full on) and the light output of an all black (full off) image. 2) ANSI contrast is measured with a pattern of 16
alternating black and white rectangles. The average light output from the white rectangles is divided by the average light output of the black
rectangles to determine the ANSI contrast ratio. When comparing the contrast ratio of projectors make sure you are comparing the same type of
contrast. Full On/Off contrast will always be a larger number than ANSI contrast for the same projector.
Full-Range: A speaker designed to reproduce the full range (20 Hz to 20 kHz) of audio frequencies.
Full Service Network (FSN) Cable networks that are intended to provide everything; that is broadcast TV, Internet access, VOD, and voice
telephony.
FXL: The most popular halogen lamp in use in lower cost projectors and overhead projectors. The lamps typically last about 40 hours, however for
convenience, most projectors using halogen lamps carry a spare, and a quick method of going to the b ackup lamp. Metal halide lamps and UHP
lamps are used in most of the medium and higher priced, more powerful portables.
G
GA Grand Alliance
Gain: Increase in level or amplitude. Gain reflects the difference between the output power of a device and the input power fed into it, with all ports
terminated at 75 Ohms.
Gain Control
Gain Slope
An adjustable control that changes the gain of an amplifier.
A linear variation in gain from the lowest frequency to the highest frequency.
Gateway
A computing machine which is both • connected to one or more networks • and is capable of passing network information from
one network to another
Generation Loss: Video degradation caused by successive recordings (dubs of other dubs) from the master source. This is overcome by digital
recording.
GIF "Graphic Interchange Format". One of the most common storage formats for image files. Used most extensively on the web.
GigaHertz (GHz) One billion cycles of electrical frequency per second.
GHz see gigahertz
GOP Group Of Pictures (motion compensation)
GPS Global Positioning System
GPRS Description not available yet.
Graphic Equalizer: A type of equalizer with sliding controls that create a pattern representing a graph of the frequency-response changes. Raising
sliders boosts the affected frequencies; lowering sliders cuts (attenuates) the affected frequencies.
Grand Alliance: U.S. consortium, formed in 1993, to produce "the best of the best" DTV transmission system from among the initially proposed
separate systems. Participants were: AT&T, General Instrument Corp., MIT, Philips Consumer Electronics, David Sarnoff Research Center,
Thomson Consumer Electronics, and Zenith Electronics Corp. The group eventually proposed the current ATSC digital standard.
Gray Scale: The ability for a video display to reproduce a neutral image color with a given input at various levels of intensity.
Ground Communication Equipment Satellite earth station electronic equipment.
H
H.264 A new video encoding layer of MPEG-4, called nowadays officially as AVC. MPEG-4 itself contains various encoding methods, called
"subsets" or "layers", and the H.264 is a latest standardized layer in the MPEG-4 standard, launched in late 2002. Other MPEG-4 layers include
Simple Profile and Advanced Simple Profile that most MPEG-4 encoders nowadays use, including DivX and RealVideo 9.
Half-Duplex Two-way transmission, one way at a time.
Halogen One of the types of light source used in projectors (the other being metal halide). Halogen lamps produce a slight yellow tint which is
imperceptible in most circumstances they also have a far short life than metal halide, measured in hundreds rather than thousands of hours.
Halogen Lamps: Used in most low and medium priced projectors, these lamps last about 40 hours, with consistent output throughout their life.
Although halogens look very white compared to a normal incandescent lamp, they are not as white as metal halide unit s. Cost of operation: Under
$0.50 per hour. Most projectors using halogen lamps carry a spare lamp inside.
Hanging Dots: An artifact of composite video signals that appears as a stationary, zipper-like, horizontal border between colors.
Hard Wired Remote: Generally a remote control is wireless, and uses infra-red transmitter. There are situations where this is not practical: Large
rooms where the speaker is 35 ft or more from the projector. Rear projection, where the screen will pass some signal, but normally has the presenter
pretty much tied down. Also, the presenter has to point the remote "at" the projector which often means turning away from the audience. A couple of
projectors (Epson for one) offer wireless remotes that will accept a cable (hard wiring) back to the projector, assuring range and signal getting
though.
HDCAM The name given by Sony to the family of HD/24p products for acquisition and post.
HD High Definition
HD-DVD Format has not been fully specified yet! This is a proposed name for a next generation DVD-Video disc. Currently (spring 2002) industry is
fighting over the specs of the standard -- there are two suggested specifications for the standard which are competing:
-suggested by most technology companies is the spec which would continue using MPEG-2 as a video format for the discs, but start using next
generation blue-laser discs instead of old red laser discs
-other proposal suggests that companies continue to use the existing DVD media which holds approx 4.36GB of data per one layer per one side, but
start using MPEG-4 as a compression format instead of currently used MPEG-2.
HDCP: High-Bandwidth Digital Content Protection. Created by Intel, HDCP is used with HDTV signals over DVI and HDMI connections and on DTheater D-VHS recordings to prevent unauthorized duplication of copy written material.
HDMI High-Definition Multimedia Interface. A new standard for video interfacing supported by Pioneer, Hitachi, Matsushita Electric Industrial
(Panasonic), Philips, Sony, Thomson (RCA), Toshiba, and Silicon Image. It has a bandwidth of up to 5Gbs which means it can easily support all
current HDTV standards. HDMI is backwards compatible with DVI. HDMI: HDTV connection format using a DVI interface that transfers
uncompressed digital video with HDCP copy protection and multichannel audio.
HDR: Hard-Drive Recorder. Device that uses a computer hard drive to store compressed digital audio and video signals.
HDTV: High-Definition Television. The high-resolution subset of our DTV system. The FCC has no official definition for HDTV. The ATSC defines
HDTV as a 16:9 image with twice the horizontal and vertical resolution of our existing system, accompanied by 5.1 channels of Dolby Digital audio.
The CEA defines HDTV as an image with 720 progressive or 1080 interlaced active (top to bottom) scan lines. 1280:720p and 1920:1080i are
typically accepted as high-definition scan rates. HDTV: Acronym for High Definition Television. Only viewable with certain DVDs and HDTV
receivers. High Definition Television A video format superior to a PAL or NTSC image, usually 16:9. These include at least18 different permutations
of frame rate and raster lines. Mastering on 24p allows conversion to any of these standards HDTV High Definition Television Broadcasting HDTV
(HIGH DEFINITION TELEVISION): This is the best picture and sound quality available on DTV. HDTV uses twice as many lines of picture as
analogue television and is also broadcast in the wide-screen, 16:9 format. True HDTV also incorporates 5.1 audio. This is far superior than the
analogue, stereo audio available on current analogue sets. HDTV: "High Definition Television." This is the most superior video picture available in
DTV. In the U.S., the 1080i and 720p formats in a 16:9 aspect ratio are the two acceptable HDTV formats. HDTV is a component of DTV. HDTV
stands for High-Definition Television and as its name suggests, it specifies a higher resolution to the viewable TV image than the existing widelyused "standard" TV formats, such as NTSC and PAL. Term HDTV is very often confused with the term DTV which simply stands for digital TV, but
doesn't actually define higher resolution than the existing resolutions of PAL and NTSC. This "normal" DTV standard is widely used in Europe with
normal PAL resolution of 704x576. European-wide standardization of HDTV specs is still largely under discussion and it is likely that Europe will
switch to digital without actually changing the resolution to a higher one. The specified HDTV resolutions that are used in United States and most
notably in Japan, are called 1080i, 720p and 720i. HDTV's native aspect ratio is 16:9 -- same as with anamorphic DVD-Video discs, but in HDTV the
resolution is "really" in 16:9 and not achieved by stretching the pixels to be wider, like in anamorphic DVD-Video discs. High Definition Television
(HDTV) - Provides crystal-clear quality widescreen pictures with compact disc-quality surround sound. The aspect ratio of HDTV pictures is 16:9,
similar to a movie screen's dimensions, as opposed to the 4:3 format of today's television. HDTV duplicates cinema display quality.
HE-AAC Full description not available yet. HE-AAC stands for High-Efficiency Advanced Audio Coding. Audio standard within the MPEG-4
standard. See also AAC
Head-End The control centre of a cable television system, where incoming signals are amplified, converted, processed and combined into a
common cable along with any original cablecasting, for transmission to subscribers. The system usually includes antennas, preamplifiers, frequency
converters, demodulators, modulators, processors and other related equipment.
Head-End Router The computer, at the cable headend, responsible for gateway operations between the headend and the Internet.
Header Protocol control information located at the beginning of a protocol data unit.
HEPA Clean filtration System High Efficiency Particulate Air Panasonic's HEPA filter removes most allergens, irritants and pollutants like pollen,
spores, dust mites, bacteria. It offers perfect protection for allergy and asthma sufferers and guarantees you a clean and fresh home every time you
vacuum
Hertz (Hz) A unit of frequency equivalent to one cycle per second.
Heterodyne A process of the shifting of a signal of interest down to a frequency at which it may be processed more easily to extract information.
HFC Hybrid Fibre Coax
Hi8 Full description not available yet. One of the best analogue video camcorder formats, developed by Sony in late 1990's. Hi8 uses the same
cassettes as Digital8 and normally all D8 digital camcorders can also play Hi8 analogue recordings.
Hi Fi High Fidelity
Hi-Fi Stereo: Feature found on VCRs that records or plays back stereo soundtracks with improved fidelity compared to using the linear stereo tracks.
High Definition Television (HDTV) A very high quality television signal with picture resolution nearly equal to that of film.
High Electron Mobility (HEMT) A transistor that yields the lowest noise figures in single FET devices.
High Gain Screen: Material that reflects more light than a reference material. Increases a projector's light output at the expense of uniformity. High
Gain Screen: A screen that uses one of many methods to collect light and reflect it back to the audience, which dramatically increase the brightness
of the image over a white wall or semi-matte screen. Technologies used include curved screens, special me tal foil screens (some polarized), and
certain glass bead screens. Prices and performance vary tremendously, but attention to the screen can make a big difference, particularly in "tough"
environments such as trade shows.
HighMAT Panasonic DVD players equipped with HighMAT (High-performance Media Access Technology - a joint development with Microsoft) can
handle discs with a mixture of data (such as different types of picture and sound files) more quickly, smoothly and easily. HighMAT benefits include
quicker disc start-up, rapid data access, and easier track navigation thanks to playlist menus.
High Pass: A filter that passes high frequencies, and attenuates low frequencies. Same as low cut.
High Q
A fibre circuit with a great deal of selectivity.
High Split When the upstream frequencies are 5-150/174-750 MHz; this split provides the greatest amount of return path.
Homes Passed The number of homes in which a cable television service is or can be made available by adding a drop to an already existing
feeder line.
Home Theatre in a Box: A complete home theatre system in one box (or at least sold together as a package). Consists of five or more speakers, a
subwoofer, and a receiver. May also include a DVD player.
Horn: A type of speaker that looks like a horn. These speakers have small drivers and very large mouths; the horn shape serves to transform the
small radiating area of the driver into the much larger radiating area of the mouth of the horn.
Hp Hewlett Packard
HQ-VCD One of the "generation 2" video formats that never happened. If you're interested of the SVCD history, please visit this site.
HTML "HyperText Markup Language". The language used for displaying web pages and some interactive training software.
Hub A signal distribution point for part of an overall system. Larger cable systems are often served by multiple hub sites, with each hub in turn
linked to the main headend with a transportation link such as fibre optics, coaxial supertrunk, or microwave.
Hue - A colour’s position in the visible spectrum from red to blue, or its gradation of tint - the professional name for a TV’s tint control.
Hybrid fibre Coax (HFC)
A network consisting of fibre optical cables and coaxial cables.
Hz: Hertz or cycles per second. Something that repeats a cycle once each second moves at a rate of 1 Hz.
I
IBC International Broadcasting Conference
ICI Inter-Carrier Interference
ID3 When MP3s became popular in late 1996, group of people started wondering if there would be a solution for the lack of information in audio
tracks stored in MP3 format. Basically the problem was that even most advanced rippers who distributed audio tracks in MP3 format, included the
information about album, track name, etc inside the filename, some morons renamed these names into something else that didn't provide the same
quality of information anymore. So, ID3 was born. ID3 is a small piece of information stored physically inside the MP3 file (in the beginning or in the
end of the file, depends on ID3's version). ID3 tags (as the pieces of information that ID3s contain are called) can contain various information about
the MP3, like album name, song name, artist, original artist, genre, composer, releasing year, additional comment fields, etc.. Nowadays ID3s are de
facto in audio world and they can be added to most of the audio formats and even to certain video formats in order to provide additional information
of the file.
IDCT Inverse Discrete Cosine Transform
IEC International Electrotechnical Commission
IEEE: "Institute of Electrical & Electronic Engineers." A professional organization that helps set transmission system standards. IEEE
Electrical and Electronics Engineers
Institute of
IEEE 1394: Networking standard for PCs. Combined with 5C copy protection, is used as a two-way connection to transfer the MPEG-compressed
digital bitstreams between consumer electronics items, including HDTV tuners and displays, D-VHS recorders, DVD players, and DBS receivers.
Also called FireWire, iLink, É IEEE.1394 See FireWire. IEEE1394 - Fast interface popular for transferring DVdigital video. Also known as FireWire or
i-Link, and has the added bonus of being able to plug devices in and out without having to reboot.
IF Intermediate Frequency
IFFT Inverse fast Fourier transform
IFO In video editing, IFO normally refers to a file on DVD-Video disc and stands for InFOrmation. While the main content of DVD-Video disc are the
VOB files which contain the actual MPEG-2 audio, video and subtitle streams, the IFO files provide information for DVD player where DVD-Video
disc's chapters start, where certain audio tracks are located, etc..
IFPI International Federation of the Phonographic Industry, the organization that represents music biz's big boys internationally, while RIAA does
the same job in the U.S. Virtually all western national copyright organizations (such as RIAA in States, Teosto in Finland, etc) are members of IFPI.
iLink: See IEEE 1394.
IMD Inter-Modulation Distortion
Imaging: The ability to localize the individual sound sources in three-dimensional space.
Impedance: A measure of the impediment to the flow of alternating current, measured in ohms at a given frequency. Larger numbers mean higher
resistance to current flow. Impedance Resistance to alternating-current flow.
Independent Operator Individually owned and operated cable television system, not affiliated with an MSP.
Inductance The ability of a device to store energy in the form of a magnetic field.
Inductor An electronic component designed to provide a controlled amount of inductance.
Infomercial A commercial, usually 90 seconds or more in length, designed to supply information about a product or service rather than to present a
specific sales message.
Infra-red Remote: The traditional remote control, it transmits infra-red, like a television remote. Typical range is limited to 30 or 35 feet. Infra-red
requires line of site or a bounce off of a hard surface. The presenter must pay attention to where the remote is pointed. Some projectors have a IR
sensor in both the front and rear of the projector, which can help a bit. When working at or near the maximum distance pointing right at the receiver is
necessary. Remember "line of sight" - a person's head, directly between your remote and the projector may be enough to render it unusable. FM
(radio frequency remote mousing systems, by comparison, have two distinct advantages, no line of sight requirement, and longer range. Infrared
(IR) - Light whose wavelength is longer than visible red. "Near infrared" wavelengths close to the visible-light range are used by remote controls.
Input: Connection on a component that receives signals from an outside source. For example, cable TV is attached to a TV input to transmit the
cable signal.
Integrated Amplifier: A combination preamp and amplifier.
Intelligent AI LCD: This function automatically determines the brightness of the scene shown on the LCD and adjusts the brightness of the backlight
in real-time. It displays images with crisp contrast according to the actual scene (darker for dark portions, brighter for bright portions).
Interactive Cable Cable systems that have the technical ability to let subscribers communicate directly with a computer at the system headend
from their television sets, using special converters and the regular cable lines. Viewers are able to order movies and video games, access library
information and request sales brochures from home.
Interactive Television: TV programming with interactive content and enhancements, blending traditional TV viewing with the interactivity of a
personal computer.
Interconnects: Any cable or wire running between two pieces of A/V equipment. For example, RCA terminated cables connecting pre/pros and
amps. Interconnect Two or more cable systems distributing a programming or commercial signal simultaneously.
Interdiction A method of receiving TV signals by jamming unauthorised signals but having all other signals received in the clear. Because the
jamming is accomplished outside the home and does not require a set-top terminal in the home.
Interface A term used in both hardware and software parlance. In hardware it refers to the connection between different elements of a system, for
example, your computer probably has an IDE interface for its hard disk drive. In software it refers to the software your computer runs to enable you to
interact with it, for example, most computers now have a GUI interface.
Interlace: Process of alternating scan lines to create a complete image. In CRT displays, every second field/frame is scanned between the first
field/frame. The first field represents the odd lines; the second field represents the even lines. The fields are aligned and timed so that, with a still
image, the human eye blurs the two fields together and sees them as one. Interlace scanning allows only half the lines to be transmitted and
presented at any given moment. A 1080i HD signal transmits and displays only 540 lines per 60th of a second. 480i NTSC transmits and displays
only 240 lines per 60th of a second. Motion in the image can make the fields noticeable. Interlaced images have motion artifacts when two fields
don't match to create the complete frame, often most noticeable in film-based material. Interlace Video scanning where each frame comprises of two
fields which together produce a complete image. Note that the two fields are spaced 1/50 or 1/60second apart. Two interlace fields are not equivalent
to one progressive frame. Interlace Full description not available yet. Method of smoothening the video picture moving by having double the amount
of frames than the video's fps value suggests. Basically, how the interlacing is done, let's say in PAL format, is that each frame is split into two
separate pictures, which both are missing half of the picture information. The split is done by its horizontal lines. The PAL video contains 576
horizontal lines -- let's say that the numbering of these lines begins from the top of the frame being the line number 1. The frame is being split to halfframe A and half-frame B -- the half-frame A would contain lines 1, 3, 5, 7, ... and the half-frame B would contain horizontal lines 2, 4, 6, 8, 10, ... So,
when the video is shown with PAL that has frame frequency (fps) of 25fps, there are 50 "half frames" per second that are being updated. First comes
the first full frame's "half A" that fills horizontal lines 1, 3, 5, .. leaving other ones blank (assuming that we start from a "zero state" that output doesn't
have anything shown before we start counting this). Then comes first full frame's "half B" that fills the missing lines 2, 4, 6, ... and leaves the existing
"half A"'s lines showing as well -- now we have the frame no.1 fully shown on screen. Then comes frame no.2's "half A" that then wipes off the frame
no.1's "half A", but leaves the frame no.1's "half B" showing. So, now we have a mixture where lines 1, 3, 5, 7, .. are being filled by frame no.2 and
lines 2, 4, 6, .. are being filled by frame no.1. Interlaced: A system of video scanning where odd- and even-numbered lines of a TV picture are
transmitted consecutively as two separate interleaved fields. Interlace is a form of compression and has been used for decades in analogue (NTSC)
TV.
Interlaced Scan Describes the way that two fields of video information are combined to create a full frame picture. One field containing odd lines and
one field containing even lines. Each field is drawn on the TV picture tube in 1/50th second. (1/60th second for NTSC)
Interlacing The television display format, where horizontal lines of pixels are illuminated in an alternating pattern rather than sequentially.
Intermodulation In a receiver, an unwanted signal sometimes interacts with the desired signal. The desired signal appears to be modulated by the
undesired signal.
International Power Supply: A unit that can operate under a international selection of power requirements. The specs of units vary widely, but the
minimum is 105-230 volts, and 50-60 cycles AC (alternating current). If you see a specification like 110v, 220v instead of a range, those ratings are
usually +/- a given percent such as 10%. Some units are "self-switching" they will automatically switch to whatever power source you plug it into.
Others will have to be switched (internally or externally to accommodate a difference volt age or cycle range.
International Television Fixed Services (ITFS) The ITFS television transmission system was first authorised by the FFF for educational television
in the 2.5 to 2.686 GHz band. The ITFS band has been re-allocated for shared operation among multipoint distribution services, multichannel
multipoint distribution services, operational fixed services, and ITFS users.
Internet, The A series of interconnected local, regional, national and international networks, linked using TCP/IP. The Internet is accessible via
telephony wires, HFC networks and by satellite.
Internet Protocol (IP) The computer network protocol (analogueous to written and verbal languages) that all machines on the Internet must know
so that they can communicate with one another.
Inverse Telecine Full description not available yet. Process where video editing tools reverse telecine process. Basically inverse telecine (or IVTC
as it is also called) brings back movie's original framerate from NTSC's 29.97fps to 24fps.
Inverted Dome: A type of speaker-driver shape; usually used for tweeters (concave).
Inverter Technology: Unique to Panasonic microwave ovens, the conventional transformer and capacitor have been replaced with an Inverter
circuit board. This has many benefits including reducing the weight of the oven, maximising the cooking capacity and most importantly; due to better
power control, improving the cooking performance .
Invert Image: Invert image flips the image from top to bottom, to compensate for ceiling mounting a projector upside down. Projectors typically
ceiling-mount upside down, because most have "keystone" correction built in to compensate for the distortion created by "pointing up" from the table
to the screen. Usual positioning has the projector about even with the bottom of the screen in a "table top position," or, even with the top of the
screen when ceiling mounted.
I/O - "Input/output." Typically refers to sending data to and from devices.
I-pictures Intra pictures (motion compensation)
IR Infra Red
IRC Internet Relay Chat and as a standard, it is older Net standard than WWW, being developed in late 1980s in Finland. IRC and its variations are
commonly known as "chat rooms", but very often the whole idea is being missed when describing IRC like that. Unlike conventional website-specific
chats, IRC is actually a network of servers that are connected to each others constantly, creating an interconnected network between these servers.
Users can then login to any of these servers by using an IRC client (most popular IRC client at the moment is called mIRC which you can download
from here). After being connected and selected their nickname, users join to channels (or chat "rooms" like non-technical people and media love to
call them). There can be virtually unlimited number of channels -- each channel is unique by its name, such as #afterdawn. The hash symbol (#)
traditionally always indicates that it means IRC channel name. Each channel can have virtually unlimited number of users -- each user can be
connecting to the channel from different IRC server or from same server or mix of these. Normally each channel has one or more operators that can
"kick" people, i.e. remove them from the channel, assign other users as operators, change channel's topics, etc. Channels can also require a
password, can be hidden from public channel listings and can require an invitation from existing channel users before a new user can join. Biggest
difference between IRC and instant messaging applications is the fact that all the users on channels normally see everything other users talk -- i.e. it
is real-time, public conversation area (whereas discussion forums aren't real-time and instant messaging is normally only between two parties,
although most of the IM applications support IRC-style group chats as well). In addition to this, IRC also supports IM-style private messaging
between users as well and many old-time IRC users see IM apps just a sidekick of IRC phenomenom. Apart from being a network of interconnected
servers and the protocol for servers and clients to communicate with, IRC also means the whole thing -- all the IRC networks (as there are several
IRC networks where servers are interconnected to other servers within that network, but that network is not connected to other IRC networks, thus
creating separate IRC networks). Biggest IRC networks at the moment are called EFNet, IrcNet and QuakeNet. IRC as a standard doesn't support
graphics, audio, etc. But it supports file transfers between connected users, using a method called DCC to transfer data.
IR Communication Standard: Many new laptops have an Infra-Red transceiver that follow a recent standard for wireless communicating with
peripherals (new laser printers complying with the standard) and networks or desktop systems. If you have a laptop like this, you know the pleasure
of walking into a room with a configured laser printer, and printing out documents without having to "plug-in." Only a couple of projectors are now
shipping that follow this standard. This allows their remote controls to talk directly to your laptop for remote mousing. A tremendous new capability,
as you are normally much closer to your computer than the projector in medium or large rooms.
IRD Integrated Receiver Decoder
Iris Adjustment: To achieve special creative effects or to cope with special lighting situations the iris (F-number) can be adjusted manually to let in
more light.
ISDB Integrated Services Digital Broadcasting
Isobarik: Also known as compound loading. By using two low frequency drivers (generally mounted face-to-face and wired electrically out-of-phase
or mounted front-to-back in a shallow tube and wired electrically in phase) you can halve the volume of the cabinet without reducing the low
frequency extension of the subwoofer.
ISO Apart from being one of the leading standards organizations, ISO refers also to a CD or DVD image (not picture..) file with an extension of .iso.
Just like other CD/DVD image formats, ISO is a file that contains full content of the disc, including every single track, directory, file and information
about the structure of the disc (i.e. ISO files can't be used as they are, but they need to be either "mounted" with tools like Daemon Tools or burned
to CD or DVD in order to see what files the disc image actually contains). Normally ISO files are being used to replicate existing CD/DVD discs,
transfer those discs over the network to other location (or to other person) and burn back to CD/DVD which then would be an identical replica of the
original disc. ISO International Standardisation Organisation
ISO (2) (Sensitivity) A value used to indicate a film's sensitivity to light. ISO also stands for the International Standards Organization. Since no
similarly defined standard exists for digital cameras, the term "ISO 100 equivalent" is used. A larger ISO value indicates that the camera can take a
better picture in dimly lit locations (such as indoors).
ITU International Telecommunication Union
IVTC See Inverse Telecine.
J
Java: A general purpose programming language developed by Sun Microsystems and best known for its widespread use on the World Wide Web.
Computer programs written in Java can run on any platform type (including set-top boxes), as long as they contain a Java Virtual Machine.
Jog/Shuttle: VCRs and DVD players with this feature allow for customized fast forward, rewind and slow-motion speeds. Usually operated by a
round dial on the remote or front panel of the machine itself.
JPEG Stands for Joint Photographic Experts Group. It's a universal encoding format for digital still pictures, graphics, etc, so that they can be easily
stored and accessed on the internet or on any compatible digital imaging device such as a camera, PC, data card, DVD-Video player, etc. JPEG
"Joint Photographic Experts Group". In computer terms it refers to am image storage format which allows you to specify the ratio between image
quality and file size (the compression ratio).JPEG A compression scheme optimised for still pictures often used where 10 to 100 times less data is
used such as transfer of pictures via e-mail. JPEG: "Joint Picture Experts Group."
K
KB - Kilobyte = 1, 024 bytes
Keep Case: Full plastic DVD casing similar to VHS rental cases. This case is preferred by a majority of collectors. See also snapper case.
Keystone: A form of video image distortion in which the top of the picture is wider than the bottom, or the left is taller than the right, or vice versa.
The image is shaped like a trapezoid rather than a rectangle.
Keystone Correction: Using optics design or other methods to apply a "negative" keystone to the image, which will partially cancel the effects of
keystoning. If you aim a projector with keystone correction at a screen with the lens level with the middle of the screen, you will not that the image at
the bottom is wider than at the top. When the projector is in normal position, pointing upward 10-25 degrees, the resulting image is fairly rectangular.
Keystoning As an image is projected onto a screen or wall, the angle created can make your projected image appear to be narrower on the bottom
than at the top. Most projector manufacturers today build in an automatic keystone correction to create a uniform image top to bottom. Some
projectors have the ability to manually adjust this characteristic while others provide more of a fixed correction solution.Keystoning: Keystoning is
caused when the projected image is not perpendicular to the screen, making the top and bottom of the image different lengths.
kHz: Kilohertz or one thousand Hz.
Kilobyte - 1, 024 bytes = 1KB
Ku-band The group of microwave frequencies from 12 to 18 GHz; the band of satellite downlink frequencies from 11.7 to 12.2 GHz.
L
Laser A device that generates coherent electromagnetic radiation in, or near, the visible part of the spectrum.
Laserdisc: A precursor to DVDs, this analog format has been embraced by film buffs for more than a decade. Laserdiscs are LP-sized discs that
usually must be flipped, and in some cases changed, in order to see an entire movie. LaserDisc: Now-defunct 12-inch disc format with excellent
analog, FM-recorded video image, and either analog or CD-quality PCM-encoded audio. Later discs used one of the analog channels to record an
RF-modulated Dolby Digital/AC3 soundtrack and/or used the PCM tracks to encoded a DTS soundtrack. LaserDisc Full description not available yet.
Semi-digital high-quality video format developed in early 1970's by Philips and MCA that hit the stores in 1978. It used to be the choice of home
video freaks until late 1990's when DVD killed it within two years. LaserDisc (or LD or CDV as it was also known) got digital sounds in late 1980's
and Dolby Surround and DTS sound in 1990's. Most of the Hollywood studios released their titles for LD in 1990's before DVD revolution. At its peak,
U.S. had over 1M LD players and Japan over 4M players and in U.S. there were over 5,000 LD retailers. The picture quality beats the crap out of
VCD, but loses in comparision to DVD-Video -- you could say that it is in par with SuperVCD in terms of video quality.
Laser Pointer: A small pen or cigar sized pointer, that contains a small battery powered laser, which can project a small, red (typically), high
intensity beam of light that is immediately very visible on the screen. Excellent for pointing to objects or text, to make a point.
Laser Rot: This is a condition found in a small fraction of laserdiscs. The condition is caused by oxidation in the aluminum layer of the disc.
Laserdiscs with this condition cease to play. Experts say it is too early to tell if DVDs will develop laser rot, but steps have been taken to prevent it,
such as use of higher-quality materials in the manufacturing of discs.
Last Mile Framing The data encapsulation and transmission protocols used between the consumer premises and the head end. Framing
techniques include ATM, MPEG and IP.
Layer In networks, layers refer to software protocol levels comprising the architecture, with each layer performing functions for the layers above it.
Layer Change: When a DVD player skips to the next layer of an RSDL disc. This usually triggers a brief pause in the audio and video.
LCD LCD Liquid Crystal Displays. When an electric current is passed across certain types of crystal it changes the way they polarise light passed
through them. These crystals are sandwiched between plates of glass to make a display as found on computers and high end projectors. LCD:
Liquid Crystal Display. A display that consists of two polarizing transparent panels and a liquid crystal surface sandwiched in between. Voltage is
applied to certain areas, causing the crystal to turn dark. A light source behind the panel transmits through transparent crystals and is mostly blocked
by dark crystals. LCD: LCD stands for liquid crystal display and comes in many forms, sizes, and resolutions. Its primary purpose is to present a
digital image for viewing. A common use of LCDs is as a display on a notebook computer.
LCOS: Liquid Crystal on Silicon
LDTV Low Definition Television
Leased Access or Leased Channel - On some systems, a public access channel for which programmers pay a fee for use and are permitted to sell
commercial time in their programming.
LED Light Emitting Diode
Leica Dicomar Lens: This advanced lens system actually incorporates 13 individual lenses, which are arranged in 9 groups and work together to
deliver images of outstanding quality. Four lens surfaces on three aspherical lenses combine to render ultra-precise images with minimal chromatic
aberration. A special multi-coating is applied to the critical parts of six lens surfaces on five lenses to minimise flaring, allowing uniformly high picture
quality even under difficult shooting conditions.
Lens Shift: The Lens Shift feature of a projector allows the optical lens to be physically shifted up and down (Vertical) or left and right (Horizontal).
Most all lens shift mechanisms are motorized with vertical lens shift being the most popular. With a projector that has lens shift you can optically
correct for keystone distorted images. It is also used to help geometrically align images when stacking projectors.
Letterbox: Format used widely on laser disc and many DVDs to fit wide-aspect-ratio movies (1.85:1 and 2.35:1, for example) into a smaller frame,
such as the 1.78:1 area of an anamorphic DVD or the 1.33:1 area of a laser disc or video tape. The image is shrunk to fit the screen, leaving blank
space on the top and bottom. This process sacrifices some vertical detail that must be used to record the black bars. Letterbox: Image of a widescreen picture on a standard 4:3 aspect ratio television screen, typically with black bars above and below. Used to maintain the original aspect ratio
of the original source (usually a theatrical motion picture of 16X9 aspect ratio or wider). Letterbox Movies, for instance, are almost always made in
widescreen format. A widescreen movie needs to be displayed on a screen with different aspect ratio from the original film, the picture frame needs
to be letterboxed. Letterboxing means adding black borders above and below the original frame.The size of the borders depends on the difference
between aspect ratios. For instance displaying a 2.35:1 widescreen picture on a conventional 4:3 TV screen requires borders that cover 40 per cent
of the screen. See Henrik Herranen's page for a more in-depth explanation to film to video conversions, and example images.
Letterboxed: See Widescreen.
Level 2.5 Teletext Improved teletext with an increased colour palette and more sophisticated graphics and colour options.
LFE: Low Frequency Effects track. The .1 channel of a Dolby Digital, DTS, or SDDS soundtrack. The LFE is strictly low-frequency information (20 to
120 Hz, with 115 dB of dynamic range) that's added to the soundtrack for extra effect. This track does not inherently contain all the bass of the
soundtrack.
Li-ion Battery: Compact and high powered Lithium-ion rechargeable battery pack. These batteries can be charged at any time as they do not suffer
from memory effect.
Line Doubling: Digital TVs and some DVD players can display lines of resolution in order, unlike traditional TVs that scan odd lines and then even
lines onto the screen. Also called "Progressive Scan."
Line-Level (Low-Level): A level of electrical signals too low to make the average speaker move sufficiently. Amplifiers receive line-level signals and
amplify them to speaker level.
Line Speed Expressed in bps, the maximum rate at which data can reliably be transmitted over a line using given hardware.
Live-Streaming: Feeding (streaming) video/audio or other data to end-users at a specific time (that is, live). Today the term is most often used for
on-line services.
Luminance A video picture can be seen to be made up of two elements, the chroma made up of colour information and the luminance made up of
colour intesity. Luminance: The black and white (Y) portion of a composite, Y/C, or Y/Pb/Pr video signal. The luminance channel carries the detail of
a video signal. The color channel is laid on top of the luminance signal when creating a picture. Having a separate luminance channel ensures
compatibility with black-and-white televisions.
LNB: Low-Noise Blocker. The receiving end of a satellite dish.
LO Local Oscillator
Local Area Network (LAN) Private transmission network interconnecting offices within a building or group of buildings, and usually designed to
convey traffic (voice, video, data, and facsimile.) A LAN usually includes a computer network made up of computer, printers and mass storage units.
Local Exchange An exchange where telephone subscriber lines connect.
Local Exchange Carrier (LED) A local telephone company within a serving area or LATA
Local Loop The set of facilities used by a telephone company to transport signals between a central office, roughly similar to a cable TV headend,
and a customer location. Also called the last mile.
Local Origination Programming produced by a local cable system for presentation on the system. It may also include syndicated programming
acquired by the system.
Long Throw Lens: A lens designed for projection from the back of a room, or rather the back of a long room. Long throw lenses would be used a
projection booth in the back of a theater, etc. A typical long throw lens might have to be 50 to 100 FT back to project a 10FT diagonal image.
LOP Limit of Perceptibility
Low Noise Amplifier (LNA) A low noise signal booster used to amplify the weak signals received on a satellite antenna. Usually found in the
receiver front ends.
Low Pass: A filter that lets low frequencies go through but doesn't let high frequencies go through. Same as high cut.
Low Pass Filter (LPF) Replaces the regular filter (used for one way transmission) on a drop, and enables a subscriber to have 2-way service. The
LPF allows low frequencies to pass, but blocks out higher frequencies.
Low Power Television Broadcast medium that is similar to commercial TV but limited in broadcast coverage area by its low power signal.
Low Split When upstream frequencies are assigned below 54 MHz.
Luminance: Component of video data that includes technical "information" about its brightness. Luminance - Component of video data that includes
technical "information" about its brightness.
Lux: A standard for measuring light, numbers provided by manufacturers usually do not provide necessary additional information to compare one
product to another.
Lux Level: A scale used to measure light intensity. All of our camcorders have a very low lux rating, meaning they can still be used in low light
levels.
M
MAC Address
An address identifies a particular medium access control (MAC) sublayer service access point.
Master Antenna Television (MATS) Antenna and distribution system which serves multiple dwelling complexes such as hotels and blocks of flats.
MCNS Multimedia Cable Network System - A consortium of CableLabs and North American multi-system operators that developed DOCSIS, a
specification for the transmission of data over a cable network that has been approved by the ITU as an international standard.
Medium Access Control (MAC) Protocol In a subnetwork, that part of the protocol that governs access to the transmission medium, independent
of the physical characteristics of the medium , but taking into account the topological aspects of the subnetworks in order to enable the exchange of
data between nodes.
Megahertz (MHz) One million cycles per second.
Microwaves High frequency radio waves used for telecommunications transmission, usually above 890 MHz. Microwave frequencies require direct
line-of-sight to operate. Trees and buildings distort or block the signal.
Microwave Oscillator A device used to generate a microwave signal. it consists of two parts:
• a resonator to control the frequency of the microwave signal, and
• an active device to generate the power.
Mid Split When upstream frequencies are assigned above 100 MHz.
Miles of Plant
The number of cable plant miles laid or strung by a cable system.
Mixer A nonlinear circuit that produces an output at the sum and difference frequencies of an applied fixed or variable oscillator called the LO, and
the RF input signal of interest.
M3U was originally developed in late 1990s as a standard playlist format for MP3s, although its use has since then expanded beyond MP3s. The
.m3u files are basically just textfiles that list one MP3 or other media file on each line, normally with full path or URL to the file. If the .m3u file is
loaded to an MP3 player, the player normally plays the list of media files in the order they are listed in the playlist (unless options such as
"randomize" have been selected in the MP3 player).
M4IF stands for MPEG-4 Industry Forum. It is an independent industry forum -- most of the companies working with digital video are members of
this industry body. M4IF defines the standards for MPEG-4 audio and video. It is a subsdiary of MPEG organization.
MAC Multiplexed Analog Components
MACH Panasonic introduced HD MACH technology with the TH-50PHW6 and TH42PHW6 plasma displays and as a result, brightness levels on
these models was boosted by 40 per cent (When compared to a Panasonic 42-inch plasma without HD MACH). The HD MACH (High Definition
Multi-facet Asymmetrical Configuration Hyper-pixel) panel is a bounded cell structure made-up of wall-like ribs. These are used to wrap each
individual cell. Increasing the area in which the phosphor can be applied dramatically improves both light-emitting efficiency and intensity. Allied to
this technology is the unique MACH Enhancer. This improves image contours making them more naturally suited for human eyes. The results are
more realistic and lifelike pictures.
Macrovision: DVD copying deterrent. If you try to run a DVD player through the composite video jack on a VCR to record a DVD onto a tape, you
will see the incompatible effects of Macrovision. DVD players must be hooked up directly to the TV, or through a receiver with video switching to get
a clear signal. Macrovision Full description not available. American company that develops various copy-protection schemes for audio and video
purposes. Is best known to have their copy-protection mechanism for VHS tapes bundled with virtually every sold pre-recorded VHS tape in the
world. Also, every DVD player sold in the U.S. has Macrovision copy-protection mechanism built-in which prevents DVDs to be recorded to VHS
cassettes without hacking either the DVD player or the VCR. They have recently also developed various audio CD protection mechanisms and
record labels have already introduced few commercial audio CDs that have Macrovision's CDDA copy-protection mechanism.
MATV Master Antenna Television
Maximum Distance: Sometimes, rarely, the distance from the screen that a projector can focus the image. Most of the time, it is the manufacturer's
opinion of how far from a screen the projector can be to cast an image that is useable (bright enough) in a fully darkened room. Generally this is very
subjective. One projector might quote a distance that allows them to produce a 25FT diagonal image, while another, brighter projector might quote a
distance that only equates to a 20FT image. Beware!
Maximum Image Size: The largest image a projector can throw in a darkened room. This is usually limited by focal range of the optics.
Maximum output level (dBuV) maximum output power for a certain level of distortion. (=intermodulation products) For a single channel amplifier
maximum intermodulation products within the channel should be <54dBc.For broadband amplifiers maximum intermodulation products within the
working band should be <60dBc.
MB - Megabyte. 1 MB = 1, 024KBs
MCC Multiplex Control Computer
MD5 is a data integrity validation mechanism, just like SFV and is used in similar ways. MD5 data is most commonly distributed as separate .md5
files alongside the main file download files and can be used to check whether the download was complete and whether the data remained
uncorrupted during the download process. MD5 data is created by a algorithm that examines the original file and creates a short(-ish) checksum
data string out of the original file's characteristics. When the file and the .md5 file are downloaded, the .md5 file can be used with a specific MD5 file
checker application to check whether the downloaded file is identical to the original file. If not, it typically means that the download is not complete or
that the downloaded file was corrupted during the data transfer.
Menu Driven: Refers to the type of controls on a projector. A typical menu driven system, will first offer a menu of major catagories such as
Computer, Video, Audio, Display, Options. After selecting Computer, you will get another menu of choices with items like brightness, contrast,
number of colors, color balance, sync. Select one of those and you can then adjust it. Many projectors which are menu driven, also offer the most
widely used functions in a non-menu fashion, such as have separate buttons on the remote for volume, brightness, and contrast, as well as switching
between channels/sources.
Megabyte: One million bytes (actually 1,048,576); one thousand kilobytes. Megabyte - 1 Megabyte (MB) = 1, 024KBs
Megachanger: CD or DVD player with massive disc storage capacity, holding 50 or more discs.
Mega Pixel: Mega refers to over 1 Million. The more pixels there are the better the picture quality in video and still mode
Metadata: Informational data about the data, included in a signal's data stream.
Metal Halide Metal halide light sources give a far brighter image and are longer lasting compared to halogen. Average life ranges from 1000-8000
hours. Metal halide lamps are now used in the vast majority of projectors.
Metal Halide Lamp: The type of lamp used in many medium and all high end portable projectors. These lamps typically have a "half-life" of 10002000 hours. That is they slowly lose intensity (brightness) as they are used, and at the "half-life" point, they are half as bright as when new. These
lamps output a very "hot" temperature light, similar to mercury vapor lamps used in street lights. Their whites are "extremely" white (with slight bluish
cast.) and make Halogen lamp's whites look very yellowish by comparison.
MHz: Megahertz, or 1 million Hz.
MKV Description not yet available
Microperforated screen An acoustically transparent screen (one which can have a speaker mounted behind it).
Midbass: The middle of the bass part of the frequency range, from approximately 50 to 100 Hz (upper bass would be from 100 to 200 Hz). Also used
as a term for loudspeaker drivers designed to reproduce both bass and midrange frequencies.
MIDI MIDI stands for Musical Instrument Digital Interface.
Midrange: The middle of the audio frequency range. Also used as a term for loudspeaker drivers designed to reproduce this range.
Mid Room Projector: Designed to sit not too close or far from the screen, for a 10FT screen, typical placement is 12.5 to 25FT away. Most midroom projectors have zoom lenses.
Mig Head: Metal In Gap head achieves a boost of luminance signal by up to 30% and chrominance signal by up to 10%. It also greatly reduces
noise giving the highest levels of picture quality.
miniDV Full description not available yet. The most popular digital camcorder format at the moment. miniDVD Full description not available yet.
miniDVD is not a real format, but a hack instead that uses standalone DVD players' abilities to play back regular CDs.Basically miniDVD is a regular
CD that has the same structure as regular DVD-Video has. Most of the standalone DVD players can be fooled to think that the disc inserted is a
regular DVD-Video disc and to play it. Biggest problem with miniDVDs is the fact that DVD movies tend to take appx. 4GBs of space and in CD you
can just fit ~700MB of data -> one movie ends up taking 6 or more CDs. Therefor most of the people don't use miniDVDs, but use some other
standalone DVD player-compliant formats instead, like VCDs, SVCDs or their varieties.
Minimum Distance: The closest position that a projector can focus an image onto a screen.
M-JPEG stands for Motion JPEG. M-JPEG is a video format that uses JPEG picture compression in each frame of the video. Frames of the video
don't interact with each other in any way (like they do in MPEG-1, MPEG-2, etc..) which results in much bigger filesize, but in other hand, it makes
the video editing easier because each of the frames has all of the information they need stored in them. M-JPEG is used in very high quality video
captures -- normally as the raw data format which is edited and compressed into another format after the editing process is completed. Unfortunaly
M-JPEG is not a standard or even standardized -- each vendor has their own codecs and normally M-JPEG files created with one codec cannot be
read with other vendor's codecs. M-JPEG is the format that we recommend you to use in your video capture process as a raw data format. Editing
this videostream is extremely easy and encoding the edited M-JPEG stream into final format (such as MPEG-1, MPEG-2 or Divx ;-)) gives normally
the best possible video quality.
MLA (Micro Lens Array) This increases the fill factor on the LCD panels and reduces the visibility of the pixel grid to almost zero. This means that
you can not see the rows and columns of pixels unless you sit too close to the screen to be comfortable.
MLP: Meridian Lossless Packing. Encoding format that is able to completely reconstruct the original signal at the receiving end. No information is lost
or discarded, regardless of how trivial it might be. Used to encode six channels of high-resolution audio on DVD-A.
MMDS Multichannel, Multipoint Distribution System,
or, multipoint microwave distribution system
Mode The path a photon takes in going from one end of an optical fibre to another.
Modem Also Modulator/Demodulator - A device that converts digital signals to analogue or converts analogue to digital, allowing computer data to
be carried over normal telephone and cable lines.
Modulation When some characteristics of an electromagnetic wave are deliberately changed or manipulated for the purpose of transmitting
information.
Modulator A device that takes the video signal and audio signal that are separated by the receiver and combines them into a signal that can be
received by an ordinary TV set.
Mono: Monophonic sound. One channel.
Monochrome - A single-colour video signal (e.g. black or white) or the luminance component of the signal.
Monomode Also Single-mode fibre - All photons take the same path down the centre of the core of an optical fibre.
Motion-JPEG: Uses JPEG (computer) compressed images as individual still frames for motion. For example, 30 Motion-JPEG frames viewed in one
second would approximate 30-fps video.
Mouse Emulator The remote control on most projectors features a mouse emulator which means you are free to move around during your
presentation and still retain control of the computer source.
MOV .mov is a file extension used by the QuickTime-wrapped files.
MP3 A compression technique used to squeeze digital music. MP3 stands for MPEG1 (Motion picture experts group 1), audio layer 3 and is
commonly used on the internet to reduce the size of a music file. That way, the file takes up less space and is also quicker to upload and download.
Because MP3s take up less space, you can burn, or record, significantly more music tracks onto a single CD, for example. But not all CD players can
'decode' the discs with MP3 format tracks. Also note, that while MP3 means more tracks, it also means less quality - compressing a music file
inevitably means data loss. MP3: MPEG-1 Audio Layer-3. Compression scheme used to transfer audio files via the Internet and store in portable
players and digital audio servers. MP3 MP3 stands for MPEG-1 Audio Layer III. It is not a separate format, but a part of MPEG-1 video encoding
format, developed by MPEG group in early 1990's. Too often people refer MP3 as MPEG-3, which is incorrect, because such format doesn't even
exist. MPEG-1 Audio Layer III (MP3) is a method to store good quality audio into small files by using psychoacoustics in order to get rid of the data
from the audio that most of the humans can't hear.MP3's bitrates vary from 8kbps (that is 8 kilobits per second, not kilobytes) to 320kbps. When MP3
phenomenom began in 1996, most of the audio files were encoded using 128kbps bitrate, which is still the most popular bitrate in the world -although most of the people agree that by using slightly higher bitrates, like 192kbps or 256kbps, the audio quality can be compared with the CD
quality.
MPAA Movie Picture Association of America represents major movie studios in the U.S. Organization has pretty much the same kind of role as
music business's RIAA has -- it tries to fight against piracy, lobbies congressmen to extend laws that would limit "fair use" rights, etc.
MPEG Stands for Motion Picture Experts Group and represents a family of digital audio and video coding standards. It enables data compression of
sound and movies so that they take up less capacity. This makes them easier to store and access over the web, a PC, a data card, etc. MPEG4 is
the latest variant. MPEG A compression scheme optimised for moving pictures whereby the potential for compression is based on the similarity of
successive pictures. MPEG Video bit-rate reduction systems determined by the Moving Picture Experts Group MPEG Moving Pictures Expert
Group. A working group of ISO/IEC in charge of the development of standards for coded representation of digital audio and video. MPEG is not an
acronym for any standard, it is the acronym for the group who develops these standards! For various standards, take a look at MPEG-1 or MPEG-2.
MPEG-1 Audio and video compression format developed by MPEG group back in 1993. Official description: Coding of moving pictures and
associated audio for digital storage media at up to about 1,5 Mbit/s. MPEG-1 is the video format that has had some extremely popular spin-offs and
sideproducts, most notably MP3 and VideoCD. MPEG-1's compression method is based on re-using the existing framematerial and using
psychological and physical limitations of human senses. MPEG-1 video compression method tries to use previous frame's information in order to
reduce the amount of information the current frame requires. Also, the audio encoding uses something that's called psychoacoustics -- basically
compression removes the high and low frequencies a normal human ear cannot hear. MPEG-1 - This is a format that allows audio and video to be
compressed and saved into bit-rates of approximately 1.5 megabits per second (as fast as a CD-ROM drive). This is almost VHS quality video and
audio
MPEG2 This is a standard established by the Moving Picture Experts Group for transmitting broadcast-quality images equivalent to S-VHS. It is one
of the compression technologies used in DVD and digital television. MPEG-2: Films must be converted to digital files in order to be stored on a DVD.
MPEG-2 is the standard compression process for these digital files. MPEG 2: Compression standards for moving images and audio are set by the
Motion Pictures Expert Group (MPEG), an international committee of industry experts. MPEG-2 is the basis for ATSC digital television transmission
in the U.S. MPEG-2 Full description not available yet. A video standard developed by MPEG group. MPEG-2 is not a successor for MPEG-1, but an
addition instead -- both of these formats have their own purposes in life; MPEG-1 is meant for medium-bandwidth usage and MPEG-2 is meant for
high-bandwidth/broadband usage. Most commonly MPEG-2 is used in digital TVs, DVD-Videos and in SVCDs. MPEG-2 - This format is a substantial
improvement from MPEG-1, using high quality video and CD quality sound. Now used by many video mediums, including DVDs and digital satellite
systems. MPEG-2 Motion Picture Expert Group - a set of protocols designed for encoding, compressing, storing and transmitting audio, video and
data in digital form. Also MPEG-4
MPEG4 has a high compression ratio, which creates a small file size that's suitable for personal computer and Internet applications. MPEG-4 Full
description not available yet. Latest compression method standardized by MPEG group, designed specially for low-bandwidth (less than 1.5MBit/sec
bitrate) video/audio encoding purposes. One of the best-known MPEG-4 encoders is DivX which since version 5 has been fully standard-compliant
MPEG-4 encoder. MPEG-4 - Based on MPEG-1, MPEG-2, and Apple’s Quicktime, this format is designed to serve video, animations, audio and text,
and compress it so that it can be broadcast over a narrow bandwidth (therefore being very quick to download from the internet). MPEG-4 is gradually
becoming increasingly popular, as it is superior to most other file formats when using over the Internet.
MPEG-7 Full description not available yet . Most of the people always think of video encoding algorithms when they hear the magic word
"MPEG". This is quite right for MPEG-7 as well, but not totally. MPEG-7 doesn't itself offer any new encoding features and it is not meant for
representing audio/video content, unlike its siblings MPEG-1, MPEG-2 and MPEG-4. Instead, it offers metadata information for audio and video files,
allowing searching and indexing of a/v data based on the information about the content instead of searching the actual content bitstream. In simplest
form, this means that by using MPEG-7, content producers can bundle information such as title, pruduction year and credits into movie or song file.
But this can already be done with methods such as ID3 tags -- MPEG-7 just takes the idea much, much further. It allows tagging events in the file
separately -- i.e. when movie file contains an explosion where the movie star "dies", MPEG-7 can contain information that would say exactly that. So,
by using simple text search, we can find all the sequences where we want to see Sylvester Stallone to "die" in various movies. Or maybe you want to
search for a song that contains word "banana" in it? Simple, if the MPEG-7 data contains lyrics (associated to the correct timeframe of course), you
can find them easily and you can also jump directly to the position in each song when the word is sung. MPEG-7 is based on XML and therefor is
universal and all the existing tools that support XML parsing should be able to read the data as well, provided that they can ignore binary parts of the
file. MPEG-7 is not used at the moment, but it is under serious development and standardization process at the moment and hopefully we see first
fully featured MPEG-7 tools within few years.
MPEG-21 Description not available yet.
MULTICASTING: Because DTV allows you to pack more information into the allotted signal using compression, we can transmit multiple channels in
the same bandwith instead of just one. Think of the broadcasting bandwith as a multi-lane freeway. You can run a big, flashy, wide-load truck
carrying an HDTV program and take up all the lanes, or you can send multiple compact cars down the same freeway, each carrying an SDTV
program. Multicasting: Option made possible by digital technology to allow each digital broadcast station to split its bitstream into 2, 3, 4 or more
individual channels of programming and/or data services. Multicast A multicast is a message that is sent out to multiple devices on the network by
a host.
Multi-direction floating head The shaver follows the contours of your face and leaves no hair un-shaved. The blades move in all directions. The
float selector allows to select three levels of floating distance.
Multi Format Playback Panasonic DVD players can play DVD-Audio, DVD-Video, DVD-RAM/R, CD, CD-R/RW, HighMAT (Level 2), WMA, MP3,
JPEG and HDCD. A single unit lets you enjoy everything from movies to audio. Compatibility varies depending on the models
MultiMedia Card: A solid state storage device used to hold digital data.
Multimode When a photon careens off the optical fibre wall as it goes from one end to the other. Other photons take different paths. There are
approximately 200 different paths in a single fibre.
Multi-pass encoding Full description not available yet. Ok, multipass doesn't come from 5th Element, but it describes the best quality audio or video
encoding method known at the moment. Using multipass technique when encoding video into another format means basically that the video encoder
analyzes the video many (multi :-) times from the beginning to the end before the actual encoding process. While scanning the file, encoder writes
information about the original video to its own logfile and uses that log to determine the best possible way to fit the video within the bitrate limits user
has set for the encoding process -- this is why multi-pass encoding is only used in VBR encoding (the CBR encoding doesn't offer any flexibility for
the encoder to determine the bitrate for each frame). Best way to understand why this is used is to think of a movie -- when there are shots that are
totally, absolutely black, like scene changes, normal 1-pass CBR encoding uses the exact same amount of data to that part as it uses for complex
action scene. But by using VBR and multi-pass, encoder "knows" that this piece is Ok with lower bitrate and that bitrate can be then used for more
complex scenes, thus creating better quality for those scenes that require more bitrate. Two most popular formats that can use multi-pass encoding
are SuperVCD and DivX.
Multiplex Regarding computers (as opposed to cinemas) this refers to dividing a signal into several parts. You've probably seen this with "video
walls" where several seperate screens each display part of an image and add up to the whole.
Multiplexing Full description not available yet. Multiplexing or muxing, when speaking of video and video editing, means basically a process where
separate parts of the video (or 'streams' as they're called in video terminology) are joined together into one file. Typical process of multiplexing is
where we have MPEG-2 video file (extension normally .m2v), an AC3 audio file and a subtitle file and we want to combine into MPEG-2 system
stream file in order to burn that file to SuperVideoCD disc. Opposite process is called as demultiplexing. Multiplexing Transmitting multiple signals
simultaneously on a single chain.
Multiplexer A device that allows several users to share a single circuit. It funnels different data streams into a single stream. At the other end of the
communications link, another multiplexer reverses the process by splitting the data stream back into the original streams.
Multiple-Rate Encoding: Instead of locking encoding at a certain constant data rate, it allows the codec to choose whatever rate is best for that
portion of the recording. Usually reduces file size with proportionally less loss in quality.
Multi Re-master This interpolation technology, a Panasonic original, increases the data density in CD or DVD signals to reproduce even highfrequency sounds outside the audible range. It increases spatial characteristics to create a level of sound quality that approaches the DVD-Audio
format. Multi Re-master processing can also be used with compression formats such as DTS, Dolby Digital, MP3 and WMA to help compensate for
signal loss. You get a full, rich sound thats difficult to distinguish from the uncompressed original, even when listening on a high-end sound system.
Multiroom: System that provides audio or video to multiple areas. Usually with only one source.
Multisource: System with multiple sources. Can also be used to describe a receiver that can provide multiple different sources into different rooms.
Multiple System Operator (MSO) A company that owns and operates more than one cable system.
Multiple Subnyquist Sampling Encoding MSSE The Japanese analogue system using more than 6 MHz per channel.
Multizone: System that provides different sources into multiple areas simultaneously.
Musepack (MP+) An audio format that produces files with better quality than MP3. This file format has the file extension .mpc or .mp+ (older
version). Musepack is based on the MPEG-1 Layer 2 standard (mp2), but includes many improvements. It is praised by the audiophiles and currently
considered as the highest quality lossy compression audio format. Currently offered for free.
Must-Carry Channels which local or national authorities stipulate must be carried by a particular operator. Usually government or local channels
that must be carried by pay-TV providers.
Muxing See multiplexing.
N
National Television Systems Committee (NTSC) The standard TV format or North America television transmission is named after this standards
committee; the format is 525 lines in a 4 MHz video bandwidth. All Tv set sold in N. America are compatible.
Narrowband Generally refers to delivery channels capable of carrying sub T1 speeds.
NCTA National Cable Television Association - The major trade association for the US cable television industry.
N-curve: See Academy Curve.
ND Filter Abbreviation for Neutral Density Filter. Attached to the front of the camera's lens, it reduces the amount of light entering the lens. When
light levels are strong, such as when outdoors in sunshine, attaching an ND filter allows you to use both your maximum aperture and slower shutter
speeds.
NDS News Data Systems (company previously called DMV)
Near Video On Demand (NVOD) Also called Advanced PPV or Enhanced PPV - Provides a consumer with a movie, or TV program, on a rotating
schedule eg every 10 minutes, thus almost achieving an on-demand system.
Negative Gain Screen: Material that reflects less light than a reference material. Often used for DLP and LCD projection systems.
Network Congestion A state of overload within a network, where there is a risk of traffic loss or service degradation.
Network Interface Unit (NUI) Also called NID (Network Interface Device) - The NIU serves as the point of demarcation between the local
exchange carrier network and the customer premise. The NIU is usually placed outside the main body of the premise, on an exterior wall.
Network Layer In open system interconnection (OSI) architecture, the layer that provides services to establish a path between open systems with a
predictable quality of service.
Network Management Within IEEE 802, the functions related to the management of the data link layer and the physical layer resources and their
stations across the IEEE 802 LAN or MAN.
Network Operations centre (NOC) A large group which is responsible for the day-to-day operations and maintenance of a network.
Network Termination Part of the Access Network, (owned by the carrier or the subscriber) located on the side of the subscriber's home. The
following are functions of the Network termination
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Grounding
Coupling of home wiring to the carrier wiring
RF Filtering
Splitting
Media conversion
Remodulation
Security and interdiction
Provisioning
Loopback testing by the carrier
New Entrant Carrier (NEC) This term is generally applied to new providers of competitive local exchange telephone services. NICAM Developed
by the BBC in the 1990s, NICAM is a TV sound encoding system. It enables the transmission of programmes in stereo and at 14-bit the sound
quality is almost as good as CD. NICAM also allows for simultaneous multi-language broadcasts. To receive a broadcast with NICAM sound, your
TV and/or VCR must be equipped with a NICAM decoder. And if you really want to know, it stands for Near Instantaneous Companded Audio
Multiplex. NICAM - Stands for Near Instantaneous Compounded Audio Multiplex. Delivers very near CD stereo sound from your television.
NIT Network Information Table (part of SI)
Node An addressable unit in a network, which can be a computer, work station or some type of communications control unit.
Noise: An unwanted portion of a signal such as hiss, hum, whine, static, or buzzing. Noise - Any unwanted signals that are not strongly correlated
with the desired signal and that usually arise from a random process. Hiss and hum are typical examples of audible noise. Visually, noise appears as
"snow" on the screen or graininess in the image.
Noise Factor Index reflecting the noise power generated by an active device
Noise Figure A measure of the ability of an amplifier to increase the strength of a signal while adding the minimum possible self-generated noise. it
is mathematically equal to ten times the log of the input S/N ratio to the output S/N ratio.
NONLINEAR: A term used for the digital editing and storage of audio, video and other data. Information (like video footage or a completed program)
is retrievable and available for use almost immediately, unlike tape based systems, which require time to move the tape to locate the footage or
program needed. Our AVID is a non-linear editing system. Nonlinear: A term used for editing and storage of audio, video and other data. Information
(footage, for example) is retrievable and processed almost immediately without having to locate it in a traditional time-line format.
NTA National Transmission Authority
NTSC In the US and Japan, NTSC (National Standards Television Committee) is the standard used for all video equipment. NTSC uses 525 lines to
make up a TV picture and scans at 60Hz. Unless otherwise specified, NTSC video equipment is only compatible with NTSC software and TV
broadcasts. NTSC "National Television Standards Commitee" NTSC is the standard video broadcast format used in America. These are several
other standards used throughout the world, most notably the PAL system so ensure compatibility if you travel with your kit internationally. NTSC:
National Television Standards Committee. Government-directed committee that established the U.S. color TV standard in 1953. Also known,
sarcastically, as Never Twice the Same Color or Never The Same Color due to the inherent difficulty in achieving proper color calibration. NTSC:
The United States broadcast standard for video and broadcasting. An older standard and lower resolution than systems used in most of the world.
NTSC A 525 line 59.94Hz composite analogue colour television system at 4.2MHz bandwidth used in the USA and Japan. NTSC: "National
Television Systems Committee" and the name of the current analog transmission standard used in the U.S., which the committee created many
decades ago. NTSC NTSC -Stands for National Television Standards Committee. The television and video standard used in most of the world.
Consists of 525 horizontal lines at a field rate of approximately 60 fields per second. Only 487 of these lines are used for picture, the rest are used for
synchronisation or extra necessary information. Color TV standard developed in the U.S. in 1953 by National Television System Committee. NTSC
is used in United States, Canada, Japan, in most of the American continent countries and in various Asian countries. Rest of the world uses either
some variety of PAL or SECAM standards. NTSC runs on 525 lines/frame and it's vertical frequency is 60Hz. NTSC's framerate is 29,97 frames/sec.
Number Portability A capability that permits telecommunications users to maintain the same telephone access number as they change
telecommunication suppliers.
O
Octave: The difference between two frequencies where one is twice the other. For example, 200 Hz is an octave higher than 100 Hz. 400 Hz is one
octave higher than 200 hz.
OFDM Orthogonal Frequency Division Multiplexing
Ogg Ogg is the umbrella for a group of several related multimedia and signal processing projects that are open source and royalty free.
Development of these projects is controlled by Xiph.org. First and best-known project of these is called Ogg Vorbis, a royalty-free audio
compression technology. Other projects under development include Ogg Tarkin and Ogg Theora.
Ogg Tarkin Ogg Tarkin is a video codec currently under development by Xiph.org Foundation and it is part of the Ogg umbrella group of
multimedia products. Tarkin is about to be released in summer 2003 or nearby. Other products in Ogg family include audio codec Ogg Vorbis and
Ogg Theora.
Ogg Theora Ogg Theora is a project under Ogg umbrella and will be released by June, 2003. It is a project that aims to integrate On2's VP3 video
codec, Ogg Vorbis audio codec and OGM multimedia container formats into a multimedia solution that can compete with MPEG-4 format.
Ogg Vorbis Full description not availble yet. OGG Vorbis is a relatively new audio compression format, which is operated by Xiph.org and its main
feature in addition to great audio quality is that it is 100% patent and royalty free, unlike its worse-sounding, commercial counterpart MP3.
OGM Full description not available yet. A container format for audio and video files
Ohm: A measure of how much something resists (impedes) the flow of electricity. Larger numbers mean more resistance.
OHP: The common abbreviation for overhead projector.
On-Demand Streaming: Sending video/audio or other data that is transmitted to the end-user upon request (widely used on news and sportsoriented Web sites, for example).
Optical Digital Cable: Fiber optic cable that transfers digital audio signals as light pulses.
Optical digital output This allows you to connect the portable to a digital surround sound processor so that you can take advantage of a movie with
a Dolby Digital 5.1 or DTS 5.1 soundtrack. A thin fibre optic cable is needed to connect the two.
Optical Image Stabiliser: The best Stabiliser system on the market, using two gyro sensors, operating 500 times per second, for detecting
movement in both the horizontal and vertical axis. Image stabilizing is also possible even during fast zooming. As this is not a digital mode the picture
is not affected by its use, allowing far superior picture quality.
Outputs: Connection on a component that sends a signal to another component via cable.
Overhead Projector (OHP): A device consisting of a light source, a transmissive or reflective platform, and a focusable lens assembly. An OHP is
designed to project images from tranparencies onto a screen. LCD projection panels are designed to be used with transmissive OHPs and work best
with OHPs that produce at least 3,000 lumens. Since 5% to 10% of the light that shines through an LCD panel gets onto the screen, a 3000 lumen
OHP will produce an image of 150 to 300 lumens. Transmissive OHPs are fairly bulky (bigger than many projectors). Reflective OHPs are fairly
portable but are not useful with LCD projection panels.
Overlay The ability of computers to "overlay" text and graphics onto images.
Overscan The area of the video picture falling outside the viewable area of the display device. In order to ensure that the display devices area is fully
utilised the picture transmitted to the device is typically slightly larger than it can display (usually an extra 5% on each edge). Programme makers
must bear this in mind and only use the "safe action" area which will be displayed.
P
P2P Full description not available yet. P2P stands for Peer-to-peer networking, popularized in late 1990s by Napster. Unlike regular network, where
all the clients make requests to one specific central server (like you all do, when you request pages from our domain, you request the pages from
one specific server), the P2P network model makes the download requests to other clients. Basically once an user logs into P2P network he/she is
immediately a client and a server simultaneously. User can download files from other users and other users can download files from the user. P2P
network model can also be used in various other ways other than distributing just files. One of the best-known P2P networking projects (although it is
not pure P2P network, because clients don't communicate with each other -- maybe we should speak of distributed computing instead, but we
mention this anyway :-) is called SETI@Home where users use their own home computers to calculate portions of massive data amount received by
radiotelescopes from outer space, in order to find extraterrestial life. Also, we should mention that original Napster network wasn't pure P2P network
either, because all download requests were passed through a centralized server maintained by Napster -- this ultimately was one of the aspects
which lead to closure of Napster in early third millennium. Shortly after Napster gained its peak popularity, several pure P2P networks emerged, most
important of those new-breed P2P networks is/was definately a network called Gnutella.
PA Power Amplifier
Packet A series of bits containing data and control information, including source and destination node addresses, formatted for transmission from
one node to another.
PAL Phase Alternate Line: a commonly used colour TV system and is the standard for all TV and video equipment used in the UK. The PAL system
uses 625 lines to make up a video or TV picture and scans at 50Hz. Unless otherwise specified, PAL video equipment is only compatible with PAL
software and TV broadcasts. PAL "Phase Alternating Line". The television and video transmission system used in the UK and parts of Europe. A
total of 625 scan lines are used to make up an image although then last 49 are used to carry information (such as teletext) and gives the CRT gun
time to return from the bottom right to the top left of the screen. PAL: A European and international broadcast standard for video and broadcasting.
Higher resolution than NTSC. PAL A 625 line 50Hz composite analogue colour television system at 5.5MHz bandwidth used in Europe, Australia and
other parts of the world. PAL Phase Alternate Line Television SystemPAL PAL (Phase Alternating Line) TV standard was introduced in the early
1960's in Europe. It has better resolution than in NTSC, having 625 lines/frame, but the framerate is slightly lower, being 25 frames/sec. PAL is used
in most of the western European countries (except France, where SECAM is used instead), Australia, some countries of Africa, some countries of
South America and in some Asian countries. There are various versions of PAL, most commonly used method is called PAL B/G, but others include
PAL I (used in the UK and in Ireland) and PAL M (weird hybrid standard, which has the same resolution as NTSC has, but uses PAL transmission
and color coding technology anyway). All of these standards normally work nicely together, but audio frequencies might vary and therefor you should
check that your appliances work in the country you're planning to use them (older PAL B/G TVs can't decode UK's PAL I audio transmissions even
that the picture works nicely). PAL - PAL stands for Phase Alternate Line. PAL is the standard for television pictures in most of Europe.
Pan and Scan: When a movie is sometimes cropped from its original theatrical aspect ratio to fit your TV. Also called standard format on some DVD
packaging.
Panel: Also known as a projection panel, LCD projection panel, or plate. The panel is the predecessor of today's projectors. It is slightly larger and
heavier than a notebook computer and the LCD it uses to produce an image is very similar to that of the notebook computer. Because panels lack
their own light source, they are designed to sit on top of a transmissive overhead projector (OHP). (See the definition of Overhead Projector for
lumen performance.) Because of its small size, low cost, and versatility, panels have been a popular solution for education applications where an
OHP is frequently available in the classroom for other instructional purposes. A few products have been built that integrated the panel and the OHP.
These were some of the earliest projectors.
PanelLink: An all digital interface used to transmit computer video from a PC/Notebook to a projector. Supports resolutions from 640x480(VGA) up
to 1600x1200(UXGA). This digital interface might someday replace the analog VGA interface typically used to connect projectors to computers.
Parametric: Equalizer with adjust-able parameters, such as center frequency and bandwidth (Q), as well as amplitude.
Passive: Not active. A passive crossover uses no external power and results in insertion loss. A passive speaker is one without internal
amplification.
Passive Component A component that requires no external source of power for it to function.
Passive Matrix LCD: The original LCDs, these are controlled by a single processing system, for the whole screen, unlike active and poly-si, which
have descrete circuits for each "pixel." This results in a panel with terrible color dynamics and contrast (typically 15:1). They are also incredibly slow:
On passive laptop computers, the cursor (or anything else) moving on the screen, goes invisible until you stop moving it (submarining) Only one or
two projectors use any type of passive matrix display.
Passive Radiator: A radiating surface (usually similar to a conventional speaker cone) that is not electrically driven but shares the same air space in
a sealed cabinet with an electrically driven loudspeaker. This arrangement is functionally similar to a loudspeaker with a vented (ported) cabinet, with
the passive radiator serving the duties of the air in the port.
PAT Programme Association Table (part of SI)
Pay Cable Cable programming services for which subscribers pay an additional fee above the basic cable service charge. Also called Premium
Cable.
Pay Cable Unit Each premium service to which a households subscribes is counted as one unit.
Pay Per View (PPV) Pay television programming for which cable subscribers pay a separate fee for each program viewed.
PC Card Adaptor: The PC Card Standard defines a 68-pin interface between the peripheral card and the socket into which it gets inserted. It
defines three standard PC Card form factors, called Type I, Type II and Type III. All PC Cards measure the same length and width, differing only in
thickness. Smaller cards can fit in larger sockets. In addition to electrical and physical specifications, the PC Card Standard defines a software
architecture to provide "plug and play" capability across the widest range of products. For Panasonic Products it is a device to allow a memory card
to be plugged into a computer for the transfer of data.
PCM: See Pulse Code Modulation.
PCM Digital Recording: Pulse Code Modulation. Analogue sounds are converted to a digital bitstream signal. 16 bit (48khz) PCM stereo recording
allows record and playback with the same sound quality as DAT, which surpasses even CD. Also, in the 12 bit (32khz) mode audio dubbing is
possible, utilising 2 stereo channels for the original sound track and 2 more for either narration or music.
Peer Entities Entities within the same layer.
Penetration Ratio of the number of cable customers to the total number of households passed by the system.
Per-Inquiry Advertising Direct response advertising for which the cable network or system running the commercial is paid based on the he
number of responses received rather than the air time used.
Personal Communications Services (PCS) Digital networks deployed in cellular; like configuration at 1.8 GHz to 2.2 GHz.
Phase: Time relationship between signals; it's all relative. Phase A relative quantity describing the time relationship between or among waves
having identical frequency. The complete wave cycle is divided into 360 equal parts, called degrees of phase.
Phase Distortion When the output of an amplifier fluctuates in phase, even though the input does not, the circuit introduces phase distortion into
the signal.
Phase Modulation When the information is impressed on a radio frequency signal by varying its phase angle.
Photodiode A semiconductor device that converts light to electrical current.
Photoresistor A device that exhibits a variable resistance, depending on the amount of the light that strikes it.
Physical Layer Layer 1, the lowest layer of the OSI model, is implemented by the physical channel. The Physical layer insulates Layer 2, the Data
Link layer, from medium-dependent physical characteristics such as baseband, broadband or fibre-optic transmission. Layer 1 defines the protocols
that govern transmission media and signals.
PictBridge: PictBridge is a new standard for direct USB printing from digital cameras to inkjet and dye sub photo printers without the use of a
computer. To get more information please go to the CIPA PictBridge web page : http://www.cipa.jp/english/pictbridge/index.html
Picture Element One of many monochrome or colour 'dots' that make up a television picture.
Piezo: A type of speaker driver that creates sound when a quartz crystal receives electrical energy.
Pincushion Refers to the curve seen in what whould be a straight line at the sides of some displays (notably CRT).
Pixel Short for: PICture Element, Pixels are the tiny dots of information that make up a digital image. The more pixels there are on the camera's
image sensor (CCD or CMOS) or display?s, the higher the image resolution will be. The higher the resolution, the clearer an enlarged print can be.
Pixel A small dot which makes up a single element of the display. For example, an XGA projector has 786,432 pixels (1024*768). Pixel: Contraction
of picture element. The smallest element of data in a video image. Pixel One picture element or one sample of digital picture information. PIXEL: A
tiny sample of video information; the "dots" that make up the television picture. Pixel: A tiny sample of video information, the "dots" that make up an
overall picture. Pixel - Pixel is shorthand for ‘picture element’. A pixel is just a small rectangle of colour, many of which are used to create a bitmap
picture or video frame.
Pixelation DVD and digital channels use compression to squeeze as much video data into the minimum bandwidth (in the case of tv channels) or to
fit a given length of video onto a dvd. If this compression is not done carefully then you may occasionally see pixelation where the image looks
rougher than it should, with smooth lines appearing jagged.
Plasma: Flat-panel display technology that ignites small pockets of gas to light phosphors.
Plastic Optical fibre (PoF) A plastic cable used, for short distances only, as an alternative to fibre optical cable. Although plastic is not as
transparent as glass, it is more malleable and less expensive. PoF is a possible choice for indoor networking.
Pluge Picture Line Up Generation Equipment, a test pattern developed by the BBC to assist in properly setting black levels in a video picture.
PMT Programme Map Table (part of SI)
Point of Presence (POP) The point where the inter-exchange carrier's responsibilities for the line begin and the local exchange carrier's
responsibility ends. Location of a communications carrier's switching or terminal equipment.
Point-to-Point A circuit connecting two nodes only, or a configuration requiring a separate physical connection between each pair of nodes.
Poly-Si (silicon) LCD: A popular LCD technology for the top of the line LCD projectors. Monochrome Poly-Si LCDs are typically placed in each of
the three color light paths inside a projector, one each for Red, Green, and Blue. This results in increased color saturation, with contrast ratios above
200:1. Poly-Si technology is also a bit faster than the Active Matrix TFT, for smooth video and multimedia.
Polysilicon A material used in the manufacture of the LCD screen in high end projectors. It gives a better contrast ratio and faster response time
than TFT LCD screens.
Port: An aperture in a loudspeaker enclosure that helps extend the usable low-frequency output. A ported enclosure is also called vented or bass
reflex. Port The physical connector on a device enabling the connection to be made.
Posterisation Posterisation is an effect which manifests itself when an area of - what should be - smooth colour transition instead is abrupt steps in
colour. For example, a smooth transition from grey to white display as grey, light grey, lighter grey then white.
Power Amp: See Amplifier.
Power Amplifier An amplifier that delivers a certain amount of alternating-current power to a load. Used in audio-frequency and radio-frequency
applications.
Power Gain An increase in signal power between one point and another. Used as a specification for power amplifiers.
Power Output: A measure, usually in watts, of how much energy is modulated by a component.
Power Transistor A semiconductor transistor designed for power-amplifier applications at audio and radio frequencies.
Power Zoom : A zoom lens with the zoom in and out controlled by a motor, usually adjusted from the projector's control panel and also the remote
control.
P-pictures Predictive pictures
PPV Pay Per View
PRBS Pseudo Random Binary Sequence
Preamplifier: A control and switching component that may include equalization functions. The preamp comes in the signal chain before the
amplifiers.
Premium Cable Cable programming services for which subscribers pay an additional fee above the basic cable service charge. Also called Pay
Cable.
Pre Outs: Connectors that provide a line-level output of the internal preamp or surround processor.
Pre Outs/Main Ins: Connectors on a receiver that provide an interruptible signal loop between the output of the internal preamp or surround
processor portion of the receiver and the input of the amplifier portion of the receiver.
Pre/Pro: A combination preamp and surround processor.
PROGRAM AND SYSTEM INFORMATION PROTOCOL (PSIP): A part of the digital signal which sends information to the digital television about
KAET programs. This information is then used to create the Electronic Program Guide the viewer uses to select programming.
Processors: Anything that processes an incoming signal in some way. Surround processors, for example, can decode a Dolby Digital signal to send
to an amp so you can hear it.
Progressive Video capture or display by scanning the image such that a frame contains a complete representation of that image. Each frame
therefore contains a complete picture and with more data uses more bandwidth than interlace scanning. Your home computer scans progressively
which is why DVD movies look better on a computer than on a conventional television which is interlace. Progressive: Refers to "progressive
scanning," as in DTV formats 480p or 720p. A system of video scanning whereby lines of a picture are transmitted consecutively (unlike interlaced),
as on computer screens. Progressive Progressive or progressive scan is basically an opposite to interlaced picture. In standard, interlaced analog
TV, the picture on TV is changed 50 or 60 times (50Hz in Europe/PAL systems and 60Hz in most NTSC systems, including the American one), but
the picture contains only every other horizontal line and the line between is left "empty" -- and the next frame then contains only the horizontal lines
missed in the last frame. So, therefor in interlaced picture, at 50Hz frequency, the picture actually changes only 25 times per second (so its
framerate is 25fps). But in progressive scan technology, every picture contains everything, so therefore 50Hz progressive scan video changes the
picture 50 times per second, having the framerate of 50fps.
Progressive Photoshot: Captures the image data and temporarily stores it in two separate field memories. Field A and field B are then combined,
eliminating the need for simulations. This results in 1.5 times the resolution of standard-recorded stills for a beautifully clear and brilliant picture.
Progressive Scan Progressive scan is a method of displaying an image on a cathode ray tube like a standard television (not an LCD or plasma
screen.) A progressive scan system displays the entire image once every sixtieth of a second. The true framerate is therefore 60 frames per second.
Progressive Scanning: Each frame of a video image is scanned complete, from top to bottom, not interlaced. For example, 480p means that each
image frame is made of 480 horizontal lines drawn vertically. Computer images are all progressively scanned. Requires more bandwidth (twice as
much vertical information) and a faster horizontal scan frequency than interlaced images of the same resolution.
Projector: A projector is a device that integrates a light source, optics system, electronics and display(s) for the purpose of projecting an image from
a computer or video device onto a wall or screen for large image viewing. There are hundereds of products available in the market and they are
differentiated by their resolution, performance and features. These devices attached to a computer or video device as you would connect a monitor.
Projection System: Display that projects image onto a screen.
PROM Programmable Read Only Memory
Protocol: Set of "rules" defining exchange of data, including timing, format, sequencing, error checking, etc.
PSI Programme Specific Information (part of SI)
PSIP: Pronounced "P-SIP" - "Program and system information protocol." A part of the ATSC digital television specification that enables a DTV
receiver to identify program information contributed by content providers and use it to create sophisticated electronic program guides. Pulse Code
Modulation: (PCM) a way to convert sound or analog information to binary information (0s and 1s) by taking samples of the sound and record the
resulting number as binary information. Used on all CDs, DVD-Audio, and just about every other digital audio format. It can sometimes be found on
DVD-Video.
Public Access In the US, a non-commercial channel set aside by a cable system for use by the public, on a first come first serve, nondiscriminatory basis.
Pure Colour Engine: The Pure Colour Engine LSI converts the CCD output signal from a complementary colour filter into an RGB signal (containing
the three primary colours in light) at an early stage and extracts the low-frequency luminance component from the RGB signal. The luminance signal
is then generated in the same way as in TV broadcasting. This innovative LSI achieves virtually the same superb colour reproduction as a 3CCD
camera system.
Pull Mode The delivery method in which a subscriber demands and receives data from the provider.
Push Mode A delivery method where the service provider transmits on a fixed, predictable schedule, or in response to an event such as the
updating of data in the subscriber's database.
PVR: Personal Video Recorder. A set-top box that allows you to customize your TV viewing experience. You must buy a receiver and the service to
take advantage of the perks: recording shows (without tapes); stopping and fast forwarding a live show; creating your own programming, etc. PVR:
Personal Video Recorder. Marketing term for Video HDRs.
Q
Q: The magnification or resonance factor of any resonant device or circuit. Also the width of affected frequencies in an equalizer. Shaped somewhat
like an adjustable width bell curve.
QAM Quadrature Amplitude Modulation
QCIF Quarter Common Intermediate Format Old video resolution name. 1/4 of CIF video resolution. Standard sizes: 176x144 (PAL) 176x120
(NTSC)
QEF Quasi Error Free
Q Factor For a capacitor, inductor or tuned circuit, the Q factor, or Q, is a figure of merit. The higher the Q, the lower the loss and the more
efficient the component.
Q-Link Connecting a QLINK compatible video and recorder and coloured television together via a scart connector simplifies the programming and
set up of the VCR. Preset signal information for example is downloaded automatically from the television making tuning straight forward. Also,
frustrating mistakes when recording can be avoided by selecting Direct Record and the VCR automatically records the source as displayed on the
television screen.
QPSK Quadrature Phase-Shift Keying
Quad-Density Pixel Distribution Increases picture resolution by increasing the effective number of pixels on the screen by 1.5 times. Offsetting one
CCD half a pixel horizontally and a whole pixel vertically fills in the gaps between the pixels from the other CCDs.
Quality of Service (QoS) The accumulation of the cell loss, delay, and delay variation incurred by the cells belonging to a particular ATM
connection.
QuickTime A digital video standard created by Apple Computers used extensively on the web. QuickTime Full description not available yet. Video
(and audio) container format developed by Apple. QuickTime is like AVI or ASF, because it doesn't define the actual compression technology the
video has to use, but just defines the video structure instead. Despite this, term QuickTime is normally used to refer to Apple's own (or licensed, in
both cases mostly meant for streaming) video encoding technology that used to produce pretty bad video quality -- something that could be
compared to RealVideo format. Recently (since 2002), Apple has started using MPEG-4 video encoding on its QT streams, producing much better, if
not excellent, video quality. Reason for this has been the huge demand from Hollywood to come up with an universal standard -- such as MPEG-4 -that would produce good quality video for broadband use.
QuickTime-Motion JPEG A format for recording moving pictures and audio. QuickTime is widely compatible, allowing easy playback of moving
pictures and audio on either a Windows or Macintosh computer.
QuintrixF Leading picture tube technology. A true flat tube that dramatically reduces screen reflection and ensures accurate, natural imaging across
the whole width of the screen.
Quintrix SR With the new Quintrix SR (Super Resolution) tubes, we have enhanced key component technologies to deliver superb picture. It
incorporates a new shadow mask configuration featuring a super fine-pitch meshing. This new mask enables greater brightness without any side
effects. Plus picture resolution and detail is also dramatically enhanced. Another benefit of the tube is that it virtually eliminates 'picture noise' for
instance no jagged edges when you see someone wearing a checked jacket. And finally, the new tube is much more energy efficient.
QXGA: QXGA is used to define a specific display resolution. Resolution is defined by the number of individual dots that a display uses to create an
image. These dots are called pixels. A QXGA display has 2048 horizontal pixels and 1536 vertical pixels giving a total display resolution of 3,145,728
individual pixels that are used to compose the image delivered by a projector. A QXGA display has 4 times the resolution of an XGA display.
R
RADAR Radio detection and range
Radio Frequency (RF) Analogue electrical signals sent over the cable. Conventional (broadcast) television and radio, as well as cable TV, deliver
RF signals to your television/radio. RF is quickly becoming yesterday's news to many cable TV providers who are installing fibre-optic lines that will
replace today's cables.
Rainbow Effect On DLP projectors some people can see colour seperation on the edged of fast moving objects. This is the inability of the DLP
colour wheels to refresh pixels fast enough. Manufacturers have reduced this effect in some projectors by increasing the speed and the number of
colour segments in the colour wheel
.
RAMDAC Random Access Memory Digital-to-Analog Converter. The part of the video card which converts digital intensity levels for RGB to analog
voltages sent to monitor. A DAC can have RAM to store look-up-table (LUT) information - hence RAMDAC. The speed of the RAMDAC (eg. 220,
250, 300, 350MHz) tells the maximum master clock rate, or video clock rate (VCLK) the image can be displayed at. You can calculate the maximum
refresh rate for a resolution using a simple formula: VCLK/(height*width) = refresh rate
Ranging The process by which a cable modem learns its distance from the headend. Ranging is a continual process, due to the expanding and
contracting of cable that occurs during the day.
RAW Format A name for data read directly from the CCD, that has only been converted from analog to digital. Data output in this format is in its
original state, i.e., it has not been processed internally by the digital camera.
RCA Recording Company of America? RCA (or phono) is the standard way of connecting audio and video components. RCA leads and sockets are
usually colour coded: red and white are used to denote the right and left channels respectively for audio components. A single yellow connector is for
video equipment RCA A type of connector used commonly on Audio/Visual equipment. RCA actually stands for "Radio Corporation of America" to
connect turntables to stereo amplifiers. RCA connector/plug/jack - The most common kind of audio connector, using a small, single-pin plug and a
coaxial shield.
RCA Jacks: Receptacles for coaxial cables carrying line-level audio signals. Also called phono-type connectors.
RCA Jack Outputs: Outputs that mix color as well as black and white signals together. Results in an image that is not as sharp or clear as S- and
component video.
RCE (Regional Coding Enhancement) What is Regional Coding enhancement(RCE)?
A: It's a digital enhancement added to some Warner Bros and Columbia DVDs to stop region 1 (R1) DVDs from playing on Region-free
DVD players.
Q: What's the difference between Region Coding and RCE?
A: Regional Coding enhancement(RCE) is an additional layer of protection which some studios have placed on select REGION 1 DVDs
to prevent them from playing on region-free or multi-region players. Region Coding is a part of the DVD spec which divides the world
into 8 regions:
Region 1: U.S., Canada, U.S. Territories
Region 2: Japan, Europe, South Africa, and Middle East (including Egypt)
Region 3: Southeast Asia and East Asia (including Hong Kong)
Region 4: Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, and the Caribbean
Region 5: Eastern Europe (Former Soviet Union), Indian subcontinent, Africa, North Korea, and Mongolia
Region 6: China
Region 7: Reserved
Region 8: Special international venues (airplanes, cruise ships, etc.)
Basically, DVDs released in each region will typically only play on players sold in that region. IE a DVD released in the UK *Region 2*
would not play on a player sold in the us *Region 1*. You can tell what Region a DVD is coded for by looking at the back of the box for a
Globe with a number on it. The number correlates to the region list above. If a DVD is listed as 'Region 0' it means that it isn't coded for
any region and should play on ALL regions players.
Q: How Can I Tell if I have a DVD that is RCE?
A: If you try to play a RCE DVD in a region-free or multi-region player that doesn't play RCE discs you'll see this map:
Q: What titles have RCE?
A: Currently the following titles have RCE• 6th Day (First Single Disc Release Only) • All The Pretty Horses• America's
Sweethearts• Anger Management• The Animal• Auto Focus •The Brothers• Bad Boys 2• Charlie's Angels• Cowboy Bebop The
Movie• Daddy Day Care • Darkness Falls • Dogtown and ZBoys• Enough • Final Fantasy: The Spirits Within (Disc 1 Only)•
Finding Forester• Ghosts of Mars • Glass House • Glitter • Hollow Man• Hollywood Homicide• Identity• In The Cut (R rated and
Unrated Versions)• Joe Dirt• A Knight's Tale• The Master of Disguise • Maid in Manhattan• Men In Black II • Mr. Deeds • National
Security • The New Guy • Once Upon A Time in Mexico. • Panic Room Superbit • Punch Drunk Love • Spiderman • The Patriot•
Saving Silverman• Snatch• South Park : Chefs ExperienceSouth Park : Xmas in South Park• Stealing Harvar• Stuart Little 2 •
S.W.A.T. • The Sweetest Thing (Rated & Unrated
Versions) • Tears of The Sun • Thomas Tank & Magic Railroad•
Tomcats• Trapped • Underworld • Urban Legend Final Cut • xXx
Q.What MGM titles have been reported to have the RCE like encoding on their first runs?
A: Currently the following titles from MGM have RCE like encoding on their first run:• Another Woman• Antitrust• Magnificent Seven•
Magnificent Seven Ride Again• The Princess Bride• Salvador
RDS Radio Data System. It was co-developed by the BBC in the 1980s and virtually all major FM stations now broadcast an RDS signal. RDS offers
a variety of features. For example, there is station name ID whereby an RDS-equipped radio displays the name of a station as well as its frequency.
And drivers are probably familiar with the traffic feature which automatically alerts you when a station broadcasts traffic news. There is also PTY or
Programme Type. This allows you to search all available broadcasts by their programme content - ie news, drama, pop, etc - at the press of a button.
Real Flat - The real flat tube gives a flatter surface to the TV screen, allowing for a far clearer picture. Also, the viewing angle lets everyone see the
television, wherever they are in the room.
RealVideo Full description not available yet. Streaming video format developed by RealNetworks. RealVideo is probably the most popular
streaming video format in the world, although its quality is horrible if you compare it to MPEG-4-based formats like DivX ;-) or WMV. Quality
compares to QuickTime quality.
Rear-Projection Television: Display that projects an image on the backside of a screen material, usually after having been reflected off of a mirror.
Rear Projection TV: A television set with a three-CRT projection system and screen all in one package. Most big-screen TVs over 40 inches are
rear projection.
Rear Screen Projection The projector is placed in a large cabinet which holds an opaque screen - making the whole system look like a very large
t.v. - and projects it's image onto the screen from behind. Most projectors have the ability to mirror the image they produce (flip left to right) in order
to work in a rear projection cabinet. Rear Screen Projection: Using an opaque screen, the projector is placed behind the screen, invisible to the
audience. It projects onto the screen and the audience sees it on the other side. Good rear projection screens actually produce brighter images than
some standard screens. So as not to waste space behind the screen, ideally a projector with a short throw lens is used. Since the projector can be
placed even with the middle of the screen, without blocking anyone's view, keystoning is not a problem. Some mid-room projectors like the Epson
have available 3rd party short throw lenses. Since the image is projected through the screen, the image must be reversed.
Rebuild The physical upgrade of a cable system , often involving the replacement of amplifiers, power supplies, passive devices and sometimes
the cable, strand, hardware and subscriber unit. Happening a lot wherever existing plant cannot cope with the demands of a return path for delivery
of interactive services.
Receiver: A component that combines both the pre-amp and the power amp in one package, usually along with an FM tuner. It translates waves and
codes to audible sounds. Receiver: Any component that receives, or tunes, broadcast signals, be it NTSC, HDTV, DBS, or AM/FM radio. Typically
refers to the single component that includes a preamp, surround processor, multichannel amplifier, and AM/FM tuner. Receiver Electronic device
which can convert electromagnetic waves into either visual or aural signals, or both. For cable television, usually the subscriber's television set.
Recording Mode Panasonic DVD recorders offer four different recording modes: EP (Extended Play), (LP) Long Play, SP (Standard Play) and XP
(eXtra Play). Which you choose depends on the quality of recording you want: XP gives the best picture quality but only allows for around one hour
of recording using a 4.7 gigabyte blank disc. EP compromises picture quality but can deliver around 12 hours record time.
Re-EQ: Short for Re-equalization. A feature found on THX-certified receivers and pre/pros. Movie soundtracks are mixed for theaters or far-field
monitors with an expected high-frequency roll-off otherwise known as an X-curve. If these soundtracks are not re-mixed for home use, they will
sound too bright when played back through home speakers or near-field monitors. Re-EQ inserts an X-curve response into the signal to compensate
for this, which takes out some of the soundtrack's excess edginess or brightness.
Region Codes: DVDs and players are encoded to perform only in certain geographical regions. For example, DVDs in North America are encoded
"Region 1." Only Region 1 players will play a Region 1 disc. Before you purchase a disc online, make sure that your DVD player can play it. Region
codeFull description not available yet. Region codes in this instance mean flags implemented in DVD-Video discs that determine the geographic area
where the DVD-Video disc is being sold and where it can be watched. Region codes are controlled normally by the DVD players. According to DVD
Forum (the association that controls DVD patents) rules, all DVD-Video capable stand-alone players need to have region control measurements
built-in. This means that a DVD player bought from the manufacturer, which is set to use Europe's region code (region code 2, same as in Japan and
in South Africa), can only play DVD-Video discs that are either region free (region code 0) or have same region as the player (==only discs sold in
Japan/Europe/South Africa work). So, with such player, it is impossible to watch DVDs sold in the U.S. (region code 1, same as in Canada) -- and
obviously vice versa, American DVD players can't be used to watch DVD-Video discs sold in Europe. The region controls are also implemented in
PC's DVD-ROM drives, normally in three levels. First of all, if the DVD-ROM drive is manufactured after 1st of January, 2000, the drive itself has
physical locks implemented in it to permit playback of only specific region code (for more information about this, read also RPC-1 and RPC-2).
Secondly, all newer operating systems, including Windows 2000 and Windows XP, have region control measurements built-in. And finally, the DVD
player software, such as WinDVD or PowerDVD, have region control measurements built-in.
Repeater A repeater is a network device that repeats signals from one cable onto one or more other cables, while restoring signal timing and
waveforms.
Residential Gateway A part of the Access Network which adds network functionality and multiplexes different services. The gateway must perform
the basic functions of media translation and address translation.
Resistance The opposition that a substance offers to the flow of electric current.
Resistor An electronic component that is deliberately designed to have a specific amount of resistance.
Resolution The first specification to look for in selecting a projector is the resolution. The figure in given in horizontal pixels x vertical pixels. The
standards are: VGA (640x480), SVGA (800x600), XGA (1024x768), SXGA (1280*1024) and UXGA (1600*1200). As more 16:9 aspect ratio
projectors and plasma screens have become available you may well see things like WXGA (Wide XGA). Resolution The technical equivalent to
sharpness and the maximum amount of picture information that can be resolved in a reproduced image. Resolution is dependant on the number of
pixels and the production tools used such as lenses, film processing, scanning and telecine transfer Resolution: Directly affects picture quality. The
higher the resolution, the more picture detail there is. Many things affect resolution, including number of bits, pixel count, format, receiver quality,
cameras, lenses and lighting used for live or taped programming, etc. Resolution In computer terms, this means the number of pixels shown on the
screen. Typical screen resolution with PC users is nowadays either 1024 times 768 (1024x768 -- first figure means the number of pixels on single
horizontal line and the second figure means the max number of horizontal lines on screen) or 1280x1024. Resolution - Directly affects picture
quality. The higher the resolution, the more picture detail there is. Many things affect resolution, including number of bits, pixel count, format, receiver
quality, cameras, lenses and lighting used for live or taped programming, etc. Resolution A measure of picture resolving capabilities of a television
system determined primarily by bandwidth, scan rates and aspect ratio. relates to fineness and details perceived.
Resonant Frequency: The frequency at which any system vibrates naturally when excited by a stimulus. A tuning fork, for example, resonates at a
specific frequency when struck.
Response Time The length of time between he occurrence of an event and the response of an instrument or circuit to that event.
Return Path or Upstream, or Reverse Path - The term used to describe traffic and paths that go from the subscriber to the headend.
Reverberation: The reflections of sound within a closed space.
Reverberation Time: The amount of time it takes the reverberation to decay 60 dB from the level of the original sound.
Reverse Image: Reverse image is a feature found on most projectors which flips the image horizontally. When used in a normal forward projection
environment text, graphics, etc, are backwards. Reverse image is used for rear projection.
Reverse Path Forwarding A technique where a router receives a packet, then floods the packet out on all paths, except the path on which it
received the packet.
RF: Radio Frequency. Television signals are modulated onto RF signals and are then demodulated by your television's tuner. VCRs and DBS
receivers often include channel 3 or 4 modulators, allowing the output signal to be tuned by the television on those channels. Also, laser discs used
an RF signal for modulating Dolby Digital 5.1 soundtracks on some movies. This requires an RF demodulator (usually referred to as an AC3-RF
demodulator) before or in the surround processor to decode the signal. RF Radio Frequency
RF Coax Output: Radio Frequency Coaxial Cable Output. This output can't produce the high-resolution picture that DVDs provide, but it will provide
for a hook-up from DVD players to older TVs.
RGB - Stands for Red Green Blue. A high-quality video system that transmits these colours through wired SCART leads. RGB Stands for red, green
and blue. A video connector or lead which offers RGB output carries these primary colours separately for greater picture quality. Inferior scart leads
may not offer RGB, so check before you buy one. RGB: Red, Green, Blue. Can refer to an unprocessed video signal or the color points of a display
device. Together these three colors make up every color seen on a display device. RGB The signals of Red, Green and Blue signals RGB: Red,
Green, Blue; the normal type of monitor used with computers, examples of usage: RGB input or output often referred to as Computer input or output.
RGB: Abbreviation for red, green and blue signals, the primary colors of light -- and television.
RIAA Recording Industry Association of America, represents major record labels in the United States and fights againts piracy, lobbies in
Congress pushing forward laws that benefit recording industry, etc. Similiar organization to RIAA, but which works internationally, is called IFPI.
Ribbon Speaker: A loudspeaker that consists of a thin, corrugated, metallic ribbon suspended in a magnetic field. The ribbon acts electrically like a
low-impedance voice coil and mechanically as a diaphragm.
Ring A network topology in which the nodes are connected in a closed loop. Data is transmitted from node to node around the loop, always in the
same direction.
RLC Run Length Coding
RMS: Root Mean Square or the square root of the arithmetic mean (average) of the square's set of values. A reasonably accurate method of
describing an amplifier's power output.
RMS Watts This is the average maximum power output of an amplifier or the maximum average power of a speaker measured at 0.1% THD (Total
Harmonic Distortion). Note that some manufacturers quote a higher THD for the RMS figure, which means that at the given rating there will be a
higher level of distortion.
Roadblocking The practice of stripping commercials in designated time periods across multiple cable channels. Can be an effective method for
catching channel surfers.
Router Hosts that are connected to more than one network and route messages between them.
RPC-1 RPC-1 term is used to refer to PC's DVD-ROM drives that were built before 1st of January, 2000. Before that date, virtually all DVD-ROM
drives permitted the user to change the region code settings of the drive freely when necessary, thus allowing watching/using DVD-Video movies
from all over the world. This was changed when the MPAA forced hardware manufacturers to implement a new technology, dubbed as RPC-2 in
their drives, that only allows max. 5 changes in the region code.
RPC-2 RPC-2 term is used to refer to PC's DVD-ROM drives that are built after 1st of January, 2000. Before that date, virtually all DVD-ROM drives
permitted the user to change the region code settings of the drive freely when necessary, thus allowing watching/using DVD-Video movies from all
over the world. Those older drives are called as RPC-1 drives. This was changed when the MPAA forced hardware manufacturers to implement a
new technology, dubbed as RPC-2 in their drives, that only allows max. 5 changes in the region code.
RPTV: Rear-Projection Television
RS Reed Solomon error protection
R&S Rhode and Schwarz
RSDL Dual Layer: Reverse Spiral Dual Layer. This is a technique in which a movie is split across two layers of a single side of a disc and is joined
together for continuous playback. DVD players switch between the layers almost instantaneously, allowing more information to be stored on the
same side of a disc and eliminating the need for "flipping." See also layer change and flippers.
RST Running Status Table (part of SI)
Rx Receiver
S
SACD: Super Audio CD. Enhanced audio format with up to six channels of high-resolution audio encoded using DSD. Requires an SACD player.
Multichannel also requires a controller with six-channel analog or proprietary digital inputs for full playback. SACD See SuperAudioCD
Sampling: Digital process by which analog information is measured, often millions of times per second, in order to convert analog to digital.
Sampling Frequency: How often a digital sample is taken of an analog wave. The more samples taken, the more accurate the recording will be.
You need to sample at a minimum of twice the highest frequency you want to capture. For example, the 44.1-kilohertz sampling rate of a CD cannot
record sounds higher than 22.05 kilohertz.
Sampling Rate: How a movie or piece of music has been recorded or copied. The higher the sampling rate, the better the quality.
Satellite An orbiting space station primarily used to relay signals from one point on the earth's surface to one or many other points. A
geosynchronous or 'stationary' satellite orbits the earth exactly in synchronization with the earth's rotation and can be communicated with using fixed
non-steerable antennas located within the satellite's 'footprint.'
Satellite Master Antenna Television System (SMATV) Systems that serve a concentration of TV sets such as an apartment building, hotel, ect.,
utilising one central antenna to pick up broadcast and/or satellite signals.
Saturation -Refers to the intensity of a colour (hue). Highly saturated yellows are illegal colours in NTSC. A measure of the dilution of a pure colour
with white light. The amount of colour in a picture.
SBE: Society of Broadcast Engineers.
SBR SBR stands for Spectral Bandwidth Replication is an audio enhancement technology designed especially for low bitrate audio and speech
codecs. It improves the perceived audio quality by increasing the bandwidth at a low bitrate, and by increasing the coding efficiency of the underlying
codec by limiting its bandwidth. SBR method can be used with any codec capable of producing an acceptable audio quality at the given level. The
codec transmits the lower frequencies of the spectrum, and the SBR algorithm takes care of the higher frequencies. The SBR decoder generates the
frequencies mostly by analyzing the lower frequencies, with a little help from low-datarate guidance information.
SBR has applications wherever bandwidth is limited. For example in Internet radio broadcasts, and mobile audio communications. It can be used for
mono, stereo, or even multi-channel audio. You can find a very informative description of SBR at Coding Technologies
Scaler A device that deinterlaces and image then scales it to the native resolution of the output device. Particularly useful with plasma screens and
projectors where it can significantly enhance picture quality.
Scan Lines: The lines drawn by an electron gun in a CRT system to make up the picture. Drawn horizontally, from left to right, starting at the top left
and working to the bottom right.
SCART - SCART stands for Syndicat des Constructeurs d’Appareils Radio Récepteurs et Téléviseurs. SCART usually refers to the SCART plug and
socket, which is a popular method for connecting television and video equipment. The SCART connector carries the video signal (in several formats)
and audio.
SCM Subjective Comparison Method
SCPC Single Carrier Per Channel
Scramble To interfere with an electronic signal or to rearrange its various component parts. in pay television, for example, the signal though ne
scrambled, and a decoder, also called a descrambler, might be necessary for the signal to be unscrambled so that only authorised subscribers would
receive the clear signal.
Screener One of the multiple terms used by movie pirates to describe the source material/copying method that was used to make a bootlegged
VCD, SVCD or DivX copy of a movie. Screener normally refers to a copy made from either VHS tape or from DVD-Video disc that are sent to movie
critics and censors before the movie is available to public through video rental chains. Normally refers to a very good quality bootlegged copy.
SDH Synchronous Digital Hierarchy
SDI "Serial Digital Interface". A standard used in broadcast and high end video systems which descibes how to transmit digital component video over
a coaxial cable.
The benefits include:
Uses standard 75ohm coaxial cable with BNC connectors
No loss of resolution or quality due to analogue->digital and vice versa conversion
No noise or artifacts created due to conversion
No loss of quality due to poor cables
Maintain the full 6.75Mhz bandwidth available in the DVD format
Lossless transmission to over 1000 feet
SD Memory Card Next generation of MultiMedia card, standing for "Secure Digital". It is a solid state storage device for still images, video footage
and music. Data can be encoded to protect copyright material. More than 520 companies worldwide support the SD standard. It is increasingly
popular as a "bridge media" that lets different types of devices share data.
SDT Service Description Table (part of SI)
SDTV: Standard Definition Television. Lower resolution subset of the ATSC's DTV system. 480i is typically accepted as an SD signal. Digital
broadcasters can offer multiple sub-programs at SDTV quality, as opposed to one or two HD programs. Digital satellite and digital cable often refer to
the majority of their programs as SDTV, somewhat erroneously, as neither system has anything to do with DTV, though both, technically, consist of a
digital 480i signal. SDTV: "Standard Definition Television." Digital formats that do not achieve the video quality of HDTV, but are at least equal, or
superior to, NTSC pictures. SDTV may have either 4:3 or 16:9 aspect ratios, and it includes surround sound. Variations of fps (frames per second),
lines of resolution, and other factors of 480p and 480i make up the 12 SDTV formats in the ATSC standard. SDTV - Standard Definition Television.
Digital formats that do not achieve the video quality of HDTV, but are still of excellent quality. SDTV may have either 4:3 or 16:9 aspect ratios, and
will include surround sound.
Sealed: See Acoustic Suspension.
SECAM The French broadcast system. Sequential Coleur A Memoire uses 625 lines scanned at 50Hz. SECAM Sequentiel Coulcur a Memoire, the
French television standard, also used in the Russia. SECAM: A French and international broadcast standard for video and broadcasting. Higher
resolution than NTSC. SECAMSECAM (Sequential Couleur Avec Memoire or Sequential Colour with Memory (or System Even Crappier than the
American Method ;-)) color TV standard was introduced in the early 1960's and implemented in France.SECAM uses the same bandwidth as PAL
but transmits the colour information sequentially. SECAM runs on 625 lines/frame with the same framerate as the PAL does, 25fps. SECAM is used
in France, former French colonies and in former communist countries in Europe. Because of its similiarity with PAL (same resolution, same
framerate), all of the modern video systems, such as DVD, VCD and SuperVHS use PAL internally (for storing the data in the storage media, etc)
and just change the color encoding to SECAM when outputting the signal back to SECAM TV. SECAM - (Sequential with Memory) Systeme
Electronique Pour Colour Avec Memorie. A colour TV format similar to PAL. This colour television system developed in France, and was used there
and in most of the former communist-block countries as well as a few other areas including parts of Africa.
Second Audio Program In A BTSC-encoded television sound carrier, a monaural audio subcarrier that can be used to transmit supplemental
foreign language translation audio or other information.
Segmented Frame 24p A technique to display a progressive image on a standard interlace monitor. 24PsF is video captured like film, is formatted
for digital recording and can pass through existing HD video infrastructure. This blurs some of the film/video boundaries. Like film, the images are
captured at a single instant in time rather than by the usual line-by-line TV scans. The images are then recorded onto tape as two segments, one
with odd lines and one with even lines. A 24PsF most accurately emulates film image capture and telecine transfer - except the video recorder
operates at film rate (24 frames-per-second ): not at television rate.The human eye finds flicker below 40Hz objectionable. When film shot at 24
frames-per-second is projected, it is done so through a shutter, which enables 48Hz, rather than 24Hz. Showing 48 segments per second reduces
the flicker that would be apparent with 24 whole frames.25PsF and 30PsF rates are also included in the ITU-R BT. 709-4 recommendation.
Sensitivity: A measurement (in dB) of the sound-pressure level over a specified frequency range created by a speaker driven by 1 watt (2.83V at 8
ohms) of power with a microphone placed 1 meter away.
Server (video): System that provides large-capacity audio and video storage for video-on-demand retrieval, transmission, post production, news,
etc. Most professional servers use digital disk storage.
Service Consumer System (SCS) The DAVIC term for the in-home infrastructure for broadband networking. The SCS consists of the following
• The Network Interface Unit (NIU), usually a modem
• The Residential Gateway (RG), which adds network functionality and multiplexes different services
• The Set-Top Unit (STU), which performs applications-specific functions such as decoding digital TV
• The Terminal Equipment (TE), which is a television, a PC or any other device.
• Consumer premises distribution (wired or wireless)
Service Data Unit (SDU) Information that is delivered as a unit between peer service access points.
SET-TOP BOX (STB): The STB is used to receive and decode the DTV signal and deliver it to a monitor. The STB may also be capable of capturing
and decoding enhanced television transmissions.
Other types of STBs are used to convert and decode data for analog cable, digital cable and small dish satellite. Some, but not all of these STBs are
also capable of decoding DTV. Set-top box (STB): Device that converts and displays data from analog cable, digital cable, or digital broadcast
television to a standard frequency (channel number) for display on a standard analog television set, or a box that receives off-air DTV signal for
display on a DTV monitor. Set-Top Box A part of the Network Access which performs application-specific functions such as decoding digital TV.
SFN Single Frequency Network
SFV Simple File Verification. Some of the downloaded files in the Net come bundled with a file that has an extension of .sfv -- this file is simply a
verification file for the downloaded file itself. SFV is basically a mathematical short checksum number based on the original file. When user
downloads the original file and the .sfv file, user can use dedicated SFV check programs that use the SFV data to check the status of the
downloaded file. If the SFV's checsum data doesn't match to the data that the validation program gets from the downloaded file, it typically means
that the downloaded file is not complete or that the downloaded file has been corrupted during the transfer and needs to be downloaded again
Share The percent of television households tuned to a particular program or category of programming.
Shared Wired Network A topology where multiple households connect to a common piece of wire.
Sharpness control - A television control that affects the mid to high frequencies of the luminance signal, which convey the subjective impression of
sharpness.
Shielded Speaker: Powerful magnets inside speakers can damage a television, so speakers placed near TVs (especially center channels) need to
be shielded to prevent this problem.
Short Throw Lens: A lens designed to project the largest possible image from short distance. Most front room projectors use short throw lens. They
are often required for rear projection, where the depth behind the screen is limited. A typical short throw lens might produce a diagonal image size of
10 FT, from a distance of 7 to 10 FT.
Skin Effect The behaviour whereby electricity migrates to the outside wall of a wire.
SI Service Information, or housekeeping details added on to the video, audio and/or multi-media data stream
Side Panels: Used with imaging a standard 4:3 picture on a wide-screen 16:9 aspect ratio television screen, typically with black bars (side panels)
on each side. Used to maintain the original aspect ratio of the source material.
SIF Simple Image Format
Signaling The process by which an end system notifies a network that it wants service.
Signal Leakage Undesired emission of signals out of a cable television system.
Signal to Noise Ratio (SNR) The sensitivity of a communications receiver is generally specified in terms of the audio signal-to-noise ratio that
results from an input signal of a certain number of microvolts. Signal-to-Noise Ratio: A comparison of the signal level relative to the noise level.
Larger numbers are better.
Simple Network Management Protocol (SNMP) Allows a TCP/IP host running an SNMP application to query other nodes for network-related
statistics and error conditions. The other hosts, which provide SNMP agents, respond to these queries and allow a single host to gather network
statistics from many other network nodes.
Simple Profile in this context is one of the video encoding layers available in MPEG-4 standard and is probably the most widely used. Popular
MPEG-4 codecs such as DivX and XviD use Simple Profile and also Advanced Simple Profile for video encoding.
Simulcast: The broadcast of the same program simultaneously over two or more different systems or channels. An accelerated amount of
simulcasting of both analog and digital programming will be required by FCC rules, during the DTV transition period.
SIS: This function makes it possible to snap off a still shot (VGA) while continuing to record a moving picture. There isn't even any need to change
recording modes. The moving pictures are recorded onto tape, and the still is recorded onto the SD Memory Card. This two-in-one capability makes
it possible to catch sudden photo opportunities without interrupting a moving picture scene.
Smart Accessory Shoe: Port on the top of the camcorder, which allows the user to attach peripheral equipment. The port has connections that
allow the equipment to draw power and information from the camera.
SMATV Satellite Master Antenna Television
SMPTE: "Society of Motion Picture and Television Engineers." A professional organization that helps set standards for American television.
SMS Subscriber Management System
S/N Signal to Noise
Snapper Case: Used by Warner Bros. and some other studios for DVD casing. This case consists of cardboard with plastic edges and a snap
closure along the right side. See also keep case.
SNR SNR stands for Signal-to-Noise ratio
Soft-Dome Tweeter: A tweeter that uses a soft fabric or plastic dome as the radiating diaphragm.
Soundfield: The total acoustical characteristics of a space, such as ambience; number, timing, and relative level of reflections; ratio of direct to
reflected sound; RT-60 time; etc.
Soundstage: The area between two speakers that appears to the listener to be occupied by sonic images. Like a real stage, a soundstage should
have width, depth, and height.
Source: A component from which the system's signals originate. DVD player, AM/FM tuners, and VCRs are sources.
Spatial Resolution The resolution/clarity of an image across a static frame. Spatial Resolution: Number of pixels horizontally and vertically in a
digital image.
Speaker: A component that converts electrical energy into acoustical energy.
Spider: Part of a loudspeaker driver's suspension that helps center the diaphragm and returns it to rest after being moved by an energized voice coil.
SPL: Sound-Pressure Level. Measured in dB.
Splitters Passive devices that divide the traffic on trunk cables and send it down feeder cables.
Spot Revenue Revenue from advertising placed on a cable system by a local or national a advertiser.
Spread Spectrum Enables the successful transmission to hostile transmission environments.
sRGB Abbreviation for Standard RGB. sRGB is the international color space standard created by the IEC (International Electrotechnical
Commission). Performing all color adjustments in this color space minimizes color disparities from input and output data collected via PC peripheral
devices, such as digital cameras, printers, and monitors.
SSDL stands for Single Sided Dual Layer DVD. For more information, see DVD-9.
SSSL stands for Single Sided Single Layer DVD. For more information, see DVD-5.
ST Stuffing Table (part of SI)
Staggercast This term is used to designate the interval of time, in NVOD; that is, the time between the beginning of a movie or program, on one
channel and the beginning of the same program on another channel. (Ex: A movie starts at 7:00 on channel 50, at 7:15 on channel 51, at 7:30 on
channel 52 - the movie is stagercast 15 minutes).
STANDARD DEFINITION TELEVISION (SDTV): Digital formats that do not achieve the quality of HDTV, but are equal to or superior to an analog
signal. SDTV signals may be broadcast in 4:3 or 16:9 formats and may or may not include Dolby Digital audio.
Standard TV: Televisions not capable of displaying digital signals.
Stream: To send data in such a way as to provide or simulate real-time delivery of media.
Streaming Full description not available yet. Sending live or on-demand video or audio broadcast over the Internet. Popular streaming video
formats include RealVideo, QuickTime and WMV.
Stretch Algorithm: A 4:3 picture from cable, satellite or over-the-air TV can be stretched to fill a 16:9 TV using stretching algorithms. Most
manufacturers accomplish this by stretching the sides of the picture more than the center, reducing noticeable distortion.
Store and Forward Technique for examining incoming packets on an Ethernet switch or bridge whereby the whole packet is read before
forwarding or filtering takes place. Store and forward is a slightly slower process than cut-through, but it does insure that all bad or misaligned
packets are eliminated from the network by the switching device.
Subscriber A household or business that legally receives and pays for cable and/or pay television service for its own use.
Subsplit A frequency division scheme that allows bi-directional traffic on a single cable. Return path signals come to the headend from 5 to 30
MHz. Forward path signals go from the headend from 54 to the upper frequency limit.
Subwoofer: A large bass driver in its own cabinet that comes in two types: powered and passive. Passive subs draw power from an amplifier or
receiver, while powered subs have their own amplifier. Subwoofer A speaker dedicated to producing powerful low frequency sounds - that's bass to
you and me! DVDs with Dolby Digital 5.1 or DTS 5.1 soundtracks are encoded with a Low Frequency Effects channel especially for those trouserflapping explosions, seismic spacecraft, rumbling thunderstorms, etc. Subwoofer: A speaker designed to reproduce very low bass frequencies,
usually those below about 80 Hz. Sub-woofer - The .1 in surround sound, a speaker designed especially for deep bass frequencies.
SuperAudioCD Full description not available yet A new optical audio storage standard that competes against DVD-Audio in order to replace the
good olde audio CD.
Super Image Stabilizer: In recording situations where shaking is likely to happen i.e. when using zoom mode, filming from a vehicle or whilst
walking, this function will stabilize the recording. (Also see Optical Image Stabilizer).
Super Shadow Mask Precision engineering increases the pitch aperture ratio of this shadow mask, ensuring the optimum amount of beam current
passes through the mask and lands accurately on the faceplate. The result is a higher, more natural brightness as well as an overall improvement in
picture performance.
SuperVCD See SVCD
SuperVHS See SVHS
SuperVideoCD See SVCD.
Supplements: "Extras" included on special edition DVDs besides the movie itself. Examples include commentary tracks, theatrical trailers, TV spots,
"making-of" documentaries, cast bios and production notes.
Surround Sound: Properly placed speakers can put you in the center of the sound, thus the surround sound effect. Surround Sound - A speaker
system in which a number of speakers surround the listener/viewer in order to create a more realistic experience.
Suspension: The elements that hold a loudspeaker driver's moving parts together, allows them to move, and helps return them to rest. Most
commonly, these include the flexible surround around the outer rim of the driver and the spider on the underside of the diaphragm. See Spider.
SVCD SVCD stands for Super Video CD (called also SuperVCD or Chaoji VCD). It is a new CD standard (actually it is currently undergoing official
standardization process) developed in 1998 by Chinese consumer electronics manufacturers, Chinese government and VCD consortium (Sony,
Philips, Matsushita and JVC). SVCD is a successor for extremely popular video format called VideoCD which was based on MPEG-1 video
encoding. SVCD itself contains MPEG-2 video stream and MPEG-1 or MPEG-2 audio stream (MPEG-1 stereo audio layer II, MPEG-2 stereo audio
layer II or MPEG-2 Multi-Channel 5.1 surround audio). It's video bitrate is normally higher than VideoCD's -- clear difference to VideoCD is the fact
that SVCD doesn't specify a certain bitrate for video. Unspecified video bitrate also causes a situation where one SVCD disc can contain various
amount of video -- normally one SVCD disc contains 35-40 minutes of video, but by reducing the bitrate, one CD can hold up to 74 minutes of
video (which is the same amount what VCD disc contains). As an addition, SVCD can also contain multiple audio streams (just like a DVD-Video
can), subtitles, still images, multi-level hierarchical menus, chapters (for indexing), hyperlinks and playlists.
Just like VCDs (and audio CDs), SVCDs require a specific way how they are burned on the CD -- just sticking all the required files into CD structure
doesn't make disc a SVCD compatible. Most of the new CD burning applications support SVCD already, so authoring your own SVCDs should be
relatively easy.
SVCD's resolution is 2x higher than VCD's, in PAL the resolution is 480x576 and in NTSC it is 480x480. Framerates are 25fps and 29.97fps, just like
in any other video format. SVCD's quality is somewhere between VideoCD and DVD-Video. Most of the DVD players can play SVCD discs which
makes is perfect format for backing up your DVD movies and a very good alternative for DivX ;-) format. SVCD has also gained popularity among
movie studios -- in Far East distribution, of course -- and most of the studios already release their movies in SVCD format in China, Hong Kong,
Taiwan, etc..
S-video: A small, round jack with a pin in the center that receives signals for black and white and color. Provides much better video quality than
composite outputs. Approaches the quality of component video. S-Video A high quality video connection which offers better picture quality than
standard RCA or composite connectors. S-Video cables have round, mini four-pin plugs and sockets. S-Video: See Y/C. S-Video: A video
transmission standard that uses a 4 pin mini-DIN connector to send video information on two signal wires called luminance(brightness, Y) and
chrominance(color, C). S-Video is also refered to as Y/C. A composite signal, typically found coming out of an RCA jack on the back of most VCRs
has the Y and C information combined into one signal. The advantage of having luminance and chrominance separated is that a comb filter is not
needed inside the video projector to separate the composite signal into the luminance and chrominance signals. A comb-filter can reduce the
sharpness of your video image.
S-Video Out: 4 pin socket used to carry high quality video signals. Luminance and Chrominance signals are carried separately to optimise picture
quality.
SVGA Abbreviation for Super Video Graphics Array. Resolution is 800 x 600 pixels. One of the standard PC display modes. SVGA: SVGA is used to
define a specific display resolution. Resolution is defined by the number of individual dots that a display uses to create an image. These dots are
called pixels. An SVGA display has 800 horizontal pixels and 600 vertical pixels giving a total display resolution of 480,000 individual pixels that are
used to compose the image delivered by a projector. SVGA - Refers to the Super Video Graphics Array (800x 600 resolution).
S-VHS: Super VHS. This format displays better resolution than standard VHS, but still doesn't approach the quality of DVD. No prerecorded material
is in this format, but it can be used in the home for better quality recordings from digital satellite or cable.S-VHS An enhanced version of the VHS
video cassette system. The 'S' stands for Super and offers superior picture quality from video tapes - but you need a compatible VCR, tapes and
socketry to take advantage of it. S-VHS: Super VHS. Enhancement to regular VHS that offers improved luminance resolution. (400 lines or so.)
SVHS Full description not available yet. SVHS stands for SuperVHS and was developed by JVC to offer better video quality than the VHS
format. SVHS can offer over 400 lines of horizontal resolution compared to appx. 250 lines of VHS (and compared to appx. 500 horizontal lines of
regular TV broadcast). SVHS uses identical-looking cassettes to those of VHS, but you can recognize the SVHS cassettes by a small hole in the
cassette container that VHS cassettes don't have. Basically it is possible to simply punch a hole to VHS cassette to record SVHS material to it, but
because VHS cassettes were developed for VHS VCRs, they normally only have enough particles on the tape to hold max 250 lines of horizontal
resolution, thus making the SVHS recording onto them useless. SVHS and VHS use the same colour modulation frequencies and bandwidths, so
colour information is always correct. This is an interesting fact, because it means that SVHS does not improve on the colour resolution of VHS,
except to reduce possible interference between chrominance in luminance. It should be noted however, while colour information is preserved,
chrominance alone cannot generate a useful picture. Despite this, SVHS recording can't be played back correctly with VHS videos, unless VHS VCR
has something called "super quality playback" that allows playing SVHS tapes, but not recording onto them.
SXGA Abbreviation for Super eXtended Graphics Array. Resolution is 1280 x 1024 pixels. This resolution is a vertical and horizontal expansion of
XGA (1024 x 768 pixels). SXGA: SXGA is used to define a specific display resolution. Resolution is defined by the number of individual dots that a
display uses to create an image. These dots are called pixels. An SXGA display has 1280 horizontal pixels and 1024 vertical pixels giving a total
display resolution of 1,310,720 individual pixels that are used to compose the image delivered by a projector.
Sweetening: Electronically improving the quality of an audio or video signal, such as adding sound effects, audio ambience or laugh tracks.
Switch A mechanical or electric device that is used to deliberately interrupt, or alter the path of the current through the circuit.
Switched Network Any network in which switching is present and is used to direct messages from the sender to the ultimate recipient. Usually
switching is accomplished by decocting and reconnecting lines in different configurations in order to set up a continuous pathway between the
sender and the recipient.
Synchronous: A transmission procedure by which the bit and character stream are slaved to accurately synchronized clocks, both at the receiving
and sending end.
System Integrators (SI) Companies that provide installation of networking equipment and possibly other services such as training or network
management.
System Loss Cable TV distribution systems are designed to compensate the cable and device losses. The spacing between cable amplifiers can
increase as system losses are minimised through the proper choice of connectors, cable and related hardware System losses are referred to as a
'dB OD cable" without reference to specific cable size or device losses. Generally these losses are understood to be at the highest operating
frequency of the system.
Systems Management Functions in the application layer related to the management of various open systems interconnection (OSI) resources and
their status across all layers of the OSI architecture.
Systems Network Architecture (SNA) IBM's layered protocols for mainframe communications.
System Operator The individual, organisation, company or other entity that operates a cable TV system.
T
Tactile Transducer: A device that turns electrical energy into mechanical energy, usually used to shake the seating in a theater. Effective in
providing visceral impact without increasing the system's actual SPL level.
Take Rate (US term) The ratio of homes that pay for a cable service to homes passed.
Tap A tap is a device which splits off a portion of the feeder line signal for the subscriber.
TCP/IP: "Transmission control protocol/Internet protocol." TCP/IP is a combined set of protocols that perform the transfers of data between two
computers.
TDM: "Time division multiplex." The management of multiple signals on one channel by alternately sending portions of each signal and assigning
each portion to particular blocks of time.
TDT Time and Date Table (part of SI)
Tek Tektronix
Telecide Means same as inverse telecine. TelecineThis term has two descriptions: 1) As movies are normally shot using 24.00fps framerate and
American TV system, NTSC, uses framerate of 29.97fps, movie framerates need to be changed in order to get them play smoothly on TV. This
process, where studios add additional frames to the picture in order to increase the framerate, is called telecine. Process where various video
editing tools reverse this process is called inverse telecine. Technical details will be added later on.
2) Telecine also means a method to make an illegal bootleg copy of an original movie. Telecine method can be done in various ways, but normally
it includes process where the movie is taken directly from the reel to digital format and then encoded into VCD, SVCD or DivX format. Other bootleg
methods include Telesync, Screener, Cam and DVD-Rip.
Telco Telephone Company - Refers the a local exchange telephone carrier.
Telecommunications Communicating over a distance through wire, radio, optical or other electromagnetic means.
Telesync One of the multiple terms used by movie pirates to describe the source material that was used to make a bootlegged pirate copy,
normally distributed in VideoCD, SVCD or DivX format. Precisely Telesync means a copy which was shot in an empty cinema or from the projection
booth with a professional camera, directly connected to the sound source. Other bootleg version methods include Telecine, Screener, Cam and
DVD-Rip.
Teletext - An option on many televisions allowing you to access teletext services. Through these, you can read the news, subtitles, TV schedules,
etc. supplied by the broadcasters. Teletext Broadcast service using several otherwise unused scanning lines (vertical blanking intervals) between
frames of TV pictures to transmit information from a central data base to receiving television sets.
Teletext Level 2.5 - A more recent upgrade from the traditional teletext allowing more detail (in graphics and text) in pages.
Television The electronic transmission and presentation of pictures and sounds.
Television Receiver-Only (TVRO) The receiving antenna dish, or complete package or dish receiver.
Temporal Resolution The resolution/clarity of an image between successive frames.
Terminal Generally, connection point of equipment, power or signal. Any 'terminating' piece of equipment such as computer terminal.
TERRESTRIAL: A broadcast signal transmitted "over the air" to an antenna. Terrestrial: A broadcast signal transmitted "over the air" to an antenna.
TFT Thin Film Transfer. TFT allows for more efficient use of the light source that creates the image from the LCD panels. TFT: Thin Film Transistor
THD: Total Harmonic Distortion
Thickwire Half-inch diameter coax cable.
Thinwire Thin coaxial cable similar to that used for television/video hookups.
Three panel LCD Some projectors use 3 LCD panels - one for each primary colour - which enhanced colour reproduction and gives a richer image.
Threshold. commonly understood as the basic signal level required for a set top box to work. i.e .picture problems occur when the signal level drops
below the threshold Threshold The minimum level at which a signal of any kind can be detected, either by the human senses or by using any
electronic instrument.
Throughput The amount of data transmitted between two points in a given amount of time, eg, 10 Mbps.
Throw distance The distance from the centre of a projector lens to the centre of the screen onto which it is projecting.
THX Apparently, when the original Star Wars movie was shown in cinemas during the late seventies, filmmaker George Lucas was unhappy with its
sound and picture quality. He set-up THX which specialises in high quality post-production work so that a film's sound and picture standard is of the
highest calibre. It's not just films that can be 'THX certified' - the company also specifies exacting standards for cinema construction, professional
equipment and home AV components, too. Incidentally, the name THX is derived from THX 1138, the first film Lucas made while he was a student in
1971. It starred Robert Duvall as a robot called THX 1138 and there have been many direct and subtle references to the title in other George Lucas
films: it was the number plate of Harrison Ford's roadster in American Graffiti and the numbers are also mentioned in the Star Wars and Indiana
Jones films. The initials stand for Tomlinson Holman's eXperiment - Tom Holman is now a professor at the University of Southern California and
widely respected as a film audio pioneer and a lead developer of the THX system (for which he won an Academy Award in 2001). THX: THX
describes a certification process. The THX label indicates the sound and video quality are endorsed by Lucasfilm. Both software (DVDs) and
hardware can carry the THX stamp of approval.THX: Certification program for home theater equipment. Uses some proprietary features, but mostly
assures a base quality level for a given room size. (See THX Select or Ultra.) Is compatible with any and all soundtrack formats. Stands for either
Tom Holman's eXperiment, after the engineer who drafted the original standard, or is named after the company's founder George Lucas' first movie,
THX 1138. Nobody agrees on which. THX - The certification for audio components of a home theater system that adhere to standards and
specifications developed by Lucasfilm THX, and can reproduce soundtracks with very high fidelity to what is obtained in a movie sound studio.
THX Select: Certification program for speakers and receivers that assures a base level of quality and performance when played in a room that's
between 2,000 and 3,000 cubic feet.
THX Ultra: Certification program for speakers, receivers, and amplifiers that assures a base level of quality and performance when played in a room
that's greater than 3,000 cubic feet.
THX Ultra 2: The newest certification from THX, THX Ultra 2 requires amplification for seven channels, boundary compensation for subwoofers, and
stricter requirements for amplifiers and speakers than THX Ultra. Dipole speakers are used for the side surround channels. Monopole speakers are
used for the surround back channel and are placed next to each other. The Ultra 2 processor accommodates both 5.1 EX/ES soundtracks, as well as
multichannel audio recordings by directing ambient sounds to the dipole speakers and discrete effects/sounds to the back channels.
Tiering Supplying cable subscribers with one or more program services beyond the basic offerings at an extra charge. Each additional price
increment is called a tier.
Time Division Multiplexing Access (TDMA) A digital technology that enables a large number of users to access, in sequence, a single radio
frequency channel without interference by allocating unique time slots to each user within each channel.
Timeline: In nonlinear editing, the area in which audio and video clips are applied, typically giving duration in frames and seconds.
Time Slip Lets you watch one recorded programme while recording another at the same time. Chase Play is an associated feature which lets you
watch a recording that has already started while continuing to record.
Tint - See Hue.
TIVO (or REPLAY TV): Two brand names for a consumer video file server. These units will continually record what you are watching on television,
allowing you to immediately replay parts of the program, pause the program, or record for viewing later. It is expected that these units will eventually
be incorporated into Set-Top Boxes and are already available in some STBs used for Direct TV.
Token The character sequence or frame, passed in sequence from node to node, to indicate that the node controlling it has the right to transmit for
a given amount of time.
Token Ring Developed by IBM, this 4 or 16 Mbps network uses a ring topology and a token-passing access method.
Topology The arrangement of the nodes and connecting hardware that comprises the network. Types include ring, bus, star and tree.
TOT Time Offset Table (part of SI)
Total Activity Report (TAR) A quarterly Nielsen report which lists all the television activity during a sweep including broadcast stations, PBS,
basic cable, pay cable, and superstations. it shows household rating and share delivery by depart in both the DMA (total market) and cable
household universe for all program sources.
TOV Threshold Of Visibility
TPS Transmission Parameter Signalling
Traffic Parameter A parameter for specifying a particular traffic aspect of a connection.
Transceiver A combination of a transmitter and a receiver having a common frequency control and usually enclosed in a single package.
Extensively used in two-way radio communications at all frequencies.
Transcoding Full description not available yet. Transcoding or more specifically Compressed-domain Transcoding means normally a reencoding process that changes the video or audio features, such as resolution or bitrate, by changing parts of the a/v content, but not by
reconstructing the content again (which is the case in encoding process). Compressed-domain transcoding also maintains the format of the file same
as in the original file.
Transducer: Any device that converts one form of energy into another form of energy, specifically when one of the quantities is electrical. Thus, a
loudspeaker converts electrical impulses into sound (mechanical impulses), a microphone converts sound into electrical impulses, a solar cell
converts light into electricity, etc. Transducer A device that converts one form of energy or disturbance into another. transducers convert AC and
DC into sound, radio waves, or other forms.
Transimpedance The transfer function of a TIA, the output voltage divided by the input current.
Transistor A semiconductor device consisting of three or four layers used for switching or amplification at frequencies ranging from direct-current to
ultrahigh.
Translator Relay system that picks up distant television signals, converts the signals to another channel to avoid interference, and retransmits
them into areas that the original television signal could not reach.
Transmission Amplifier (TIA) A devise used to convert input currents to output voltages.
Transmission Control Protocol/Internet Protocol (TCP/IP) Are the standard network protocols in UNIX environments. They are almost always
implemented and used together and called TCP/IP.
Transmission Line: A (sub)woofer cabinet design where the driver is mounted at one end of a tube with the same diameter as the radiating area of
the driver and a length of 1/4 wavelength of the 3dB down frequency. This "tube" may or may not be round and may be folded to decrease the size of
the cabinet.
Transmission Link The physical unit of a subnetwork that provides the transmission connection between adjacent nodes.
Transmission Medium The material on which information signals may be carried, such as an optical fibre, coaxial cable and twisted-wire pairs.
Transmission Systems The interface and transmission medium through which peer physical-layer entities transfer bits.
Transmit Delay The time difference between the instant at which the first bit of a PDU crosses one designated boundary and the instant at which
the last bit of the same PDU crosses a second designated boundary.
Transponder The part of a satellite that receives and transmits a signal.
TREC Timing Recovery
Trunk Amplifiers The amplifiers along the trunk line responsible for maintaining signal strength must have low distortion, low noise and moderate
gain. Degradation of the signal along the trunk cannot ne corrected down stream, in fact, cascade amplifiers with similar faults simply amplify the
fault too. trunk amplifiers compensate for cable losses with automatic slope control (ASC) and automatic gain control (AGC).
Trunk Cable Cables that carry the signal from the headend to groups of subscribers.
Trunking Transporting signals from one point to another.
Trunk Line Radiating out from the headend are trunk lines which carry the main CATV signal to be distributed.
TS Transport Stream
TSG Test Signal Generator
TTL Transistor Transistor Logic
Tuner: See Receiver.
Tweeter: A speaker driver designed to reproduce high frequencies; usually those over approximately 5,000 to 10,000 Hz simultaneously.
Twitter With an interlaced picture (which is what we're all seeing when we watch t.v., video or a standard dvd player) each frame is made up of 2
fields. When field 1 is created odd (1,3,5,7,9 etc.) scan lines are drawn. When field 1 is complete field 2 is created (scan lines 2,4,6,8 etc.) hence we
have an interlaced picture. Imagine a horizontal line moving from the top of the screen to the bottom. As it moves it exists at a given position when
field 1 is drawn but has moved downwards by the time field 2 is drawns. The resulting filcker, or shimmering effect which can be seem at the edges
of the line is twitter.
Tx Transmitter
Typical Operating Conditions Optimum operating conditions for a stated number of channels.
U
UHF Ultra High Frequency 300-1000 MHz. Ultra High Frequency (UHF) Channels above channel 13 (or from 470 MHz to 806 MHz).
Unbundling The separation and discrete offering of the components of the local telephone service. Unbundling of network components facilitates
the provision of pieces of the local network, such as local switching and transport, by telephone company competitors.
Uniformity: Even distribution across a given space. In video, uniformity can refer to the distribution of light (hot spotting) or color.
Unity Gain: Output that equals the input. Unity gain screen material reflects as much light as the reference material. Has an even dispersion of light.
Universal Remote: Remote that has the commands of numerous brands stored into memory and can control several different devices
Unspecified Bit Rate (UBR) The UBR service class is intended for delay-tolerant or non-real-time applications, or those which do not require
tightly constrained delay and delay variation.
Upconversion The reproduction of a lower resolution image such as PAL/NTSC to a high definition image.
Upconverting: Process which increases the number of pixels or frame rate or scanning format used to represent an image by interpolating existing
pixels to create new ones at closer spacing. Process does not increase the resolution of image. Upconverting is done from standard definition to high
definition. (See Downconverting.)
Upconverter A device used to add a lower frequency to a microwave frequency.
Up-res-ing The process whereby an image of a lesser resolution is displayed at a higher resolution to match the quality of the intercut highresolution material.
Upstream or Reverse Path or Return Path
The term used to describe traffic and paths that go from the subscriber to the headend.
USB Universal Serial Bus. A connection port for transfering digital data. Fast data transfer speed of up to 12 Megabits per second. USB - USB
stands for Universal Serial Bus and allows you to connect devices (such as a camcorder) to your computer quickly and easily. USB allows for Plugand-Play settings (i.e. plug the device into your computer and it should be instantly compatible). USB is now one of the dominant interfaces for
connecting almost all computer peripherals, including camcorders. USB Terminal for PC Video and stills stored on memory cards can be transferred
to a PC at high speed via USB terminal. Attach your images to email or post on the Web. (all models)
USB 2.0 High-speed 480-Mbps data transfer interface. Approximately 40 times faster than USB1.1 (12 Mbps).
UV Filter A filter designed to cut UV (ultraviolet) light. Also used as a lens protection filter.
UXGA Abbreviation for Ultra eXtended Graphics Array. Resolution is 1600 x 1200 pixels. This resolution is a vertical and horizontal expansion of
XGA (1024 x 768 pixels).
UXGA: UXGA is used to define a specific display resolution. Resolution is defined by the number of individual dots that a display uses to create an
image. These dots are called pixels. A UXGA display has 1600 horizontal pixels and 1200 vertical pixels giving a total display resolution of 1,920,000
individual pixels that are used to compose the image delivered by a projector
V
V2000 Full description not available yet. One of the three competing video formats in early 1980's, developed by Philips in order to beat the crap
out of Sony's BetaMax and VHS. It has some unique features that other VCR formats didn't have -- the cassette can be flipped over, just like a
regular C-cassette and it also had linear stereo already in early '80s. It was also the first VCR format to achieve noise-free still picture and many
other achievements. Unfortunately Philips ceased the development of this format in late '80s. For more information, I suggest you to read this
excellent website: http://v2000.palsite.com/
Value-Added Reseller (VAR) Refers to distributors that also provide other services such as systems integration or network management.
Variable Bit Rate A 'bit' is a single piece of digital data. This data is compressed so that you can record more on a single disc. The Variable Bit Rate
continuously controls the amount of compression for a more efficient recording. Variable Bit Rate (VBR) A type of telecommunications service
characterised by a service bit rate specified by statistically expressed parameters that allow the bit rate to vary within defined limits.
VAS: The volume of air that offers the same degree of restoring force on the loudspeaker driver's cone as that of the cone's suspension.
VBR Full description not available yet.VBR stands for Variable Bitrate -- as opposed to CBR.
VCD VCD stands for VideoCD (version 2.0 to be more specific). VideoCD is a standard developed in early 1990's that allows regular CD to contain
74 minutes of video and audio. Both, video and audio, are encoded in MPEG-1 format and stored on the CD in specific format. VideoCDs can be
played in most of the stand-alone DVD players, in all stand-alone VCD players and in all computers that have CD-ROM drive. This is the VCD's
strong point against DivX format which is based on MPEG-4 audio/video encoding technology. VideoCD resolution is in PAL format 352 x 288 pixels
with 25 frames/second. In NTSC format it is 352 x 240 pixels with 29,97 frames/second (except in NTSC film format, where the framerate is 23,976
frames/second. Audio is encoded with bitrate of 224 kbit/sec in MPEG-1 Layer2 format (in both PAL and NTSC versions). Video is encoded with
bitrate of 1150 kbit/sec. VideoCDs are pretty rare in western countries -- basically only VCDs you see in the Europe or in the U.S. (except in NYC's
Chinatown, which is a true VCD paradise in middle of the western city :-) are illegal copies or porn movies. On the other hand, VCD is a very popular
method for movie distribution in China, Hong Kong, Singapore, Malaysia, etc.. Some studios release some of their movies officially for VCD format in
Asia. It has almost completely replaced regular VHS format in Asia, because cheap VCD recorders are widely available there. VideoCD's successor
is called SuperVideoCD.
V-chip: Technology that blocks content. The chip reads transmitted ratings from television programs and blacks them out at the level set by the TV
owner. V-Chip Violence Chip A term used to describe a microchip which will permit parental control over rated television programs.
VCR: See Video Cassette Recorder.
VCR Plus: VCR feature that, once programmed, allows the user to input the TV guide code for a given program into the VCR, which then
automatically sets itself to record that program.
Velocity Modulation Regulates the speed of the electron beam to keep the picture tightly focused at all times.
Vented: See Port or Passive Radiator.
Vertical Aperture Control Sense and adjusts brightness in the vertical plane.
Very Small Aperture Terminal VSAT Small earth stations with a satellite dish usually 1-2 metres in diameter used to receive high speed data
transmissions; can also transmit slow-speed data.
VFZ Abbreviation for Vector Format for Zooming. This next-generation digital image format uses lossless compression to save an image at 2/3 its
original size. Unlike standard digital compression, which makes it difficult to reuse data, this format allows the easy enlarging and reducing of data,
with no loss in quality.
VGA Abbreviation for Video Graphics Array. A graphics system developed by IBM. Resolution is 640 x 480 pixels and uses 16 colors. Widely used
as a standard for PC graphics systems. VGA: VGA is used to define a specific display resolution. Resolution is defined by the number of individual
dots that a display uses to create an image. These dots are called pixels. A VGA display has 640 horizontal pixels and 480 vertical pixels giving a
total display resolution of 307,200 individual pixels that are used to compose the image delivered by a projector. VGA - Refers to the standard Video
Graphics Array adapter card or function of your computer. Standard VGA resolution is 320x240 pixels, while Super VGA resolutions are 640x480,
800x600, and 1024x768
VHF Very High Frequency 50-300 MHz Very High Frequency VHF Channels 2-13 (54 - 88 MHz and 174 - 216 MHz)
VHS: Vertical Helical Scan (or as JCV calls it, "Video Home System"). Widely used method of recording audio and video electrical signals onto
magnetic tape. VHS
Full description not available yet. Vertical Helix Scan. Video casette format and technology introduced by JVC in 1976.
Competed with Sony's BETA format. Eventually VHS came out as a winner and BETA died out. SVHS (SuperVHS) is an improved, high-resolution
VHS standard.
Video A term pertaining to the bandwidth and spectrum of the signal which results from television scanning and which is used to produce a picture.
Video Capture The act of "capturing" an analogue video source and converting it to a digital format.
Video Cassette Recorder: Device that records audio and video electrical signals onto magnetic tape (aka videotape recorder).
VideoCD See VCD.
Video Dialtone The means by which telephone companies may provide transmission facilities and for on-telco video programming as well as
certain enhanced services to third-party programmers.
VIDEO DISPLAY UNIT (VDU): Formerly known as your TV, now called your VDU or your monitor, the device containing the television tube or tubes
which display the television picture.
VIDEO FILE SERVER: A unit which uses computer hard drives rather than magnetic tape to record and playback video and audio. Because these
units are "non-linear" a program may be broadcast while the end of the program is still being recorded. They are also very useful in editing television
programs, since pieces of the programs can be easily moved about.
Video-on-Demand (VOD): When video can be requested at any time, solely at the discretion of the end-user (viewer). Video On Demand (VOD)
Allows the end-user subscriber to select movies they wish to view from a large selection of titles and categories stored on a remote server at any
time. Service may also provide VCR functionality, (stop, pause etc) which allows the end-user subscriber to control the 'play back' of the server from
the remote control.
Videotex The generic term used to refer to a 2-way interactive system for the delivery of computer-generated data into the home, usually using the
television set as a display device. Some of the more often used specific terms are 'viewdata' for telephone-based systems (narrowband interactive
systems); 'wideband broadcast' or 'cabletext' for systems utilising a full video channel for information transmission; and 'wideband 2-way teletext' for
systems which could be implemented over 2-way cable television systems. In addition, hybrids and other transmission technologies, such as
satellite, could be used for delivery of videotext services on a national scale.
Viewers Per Viewing Household (VPVH) A demographic percentage which indicates how many persons per 100 or per 1000 households are
viewing. For example, a VPVH of 80 K2-11 means that for every 100 households viewing, there are an estimated 80 children ages 2 to 11.
Virtual Channel (VC) The communication channel that provides for the sequential unidirectional transport of ATM cells.
VLC Variable Length Coding
VOB Full description not available yet. VOB stands for DVD Video Object. It is basically one of the core files found on DVD-Video discs and
contains the actual movie data. Basically VOB file is just a basic MPEG-2 system stream -- meaning that it is a file that contains multiplexed MPEG2 video stream, audio streams (normally AC3 format) and subtitle streams.
Volt: The unit of electrical potential, or difference in electrical pressure, expressing the difference between two electrical charges.
Vorbis See Ogg Vorbis
VP3 VP3 is a video codec originally developed by On2 Technologies, which donated the codec to Xiph.org Foundation in summer 2002 as an open
source project. On2 still has further developer propietary version of VP3 among its products, currently called as VP5. VP3 codec is now part of
Xiph.org Foundation's Ogg Theora project, which aims to integrate Ogg Vorbis audio codec and VP3 into a fully integrated multimedia platform that
would compete against likes of MPEG-4.
VQF Full detailed description not available yet. One of the "alternative" audio compression formats back in 1990s that was aimed to take over MP3
by providing better audio quality than MP3 with lower bitrate. Failed miserabely due various reasons, most notably because of restrictive licensing.
Nowadays the only serious alternatives to MP3 are probably Ogg Vorbis and Microsoft's WMA.
VSB Vestigial Side Band modulation system, prefixed by,
8 for 8 level terrestrial or 16 for 16 level cable version VSB: "Vestigial side band." VSB is an analog modulation technique used to reduce the amount
of spectrum needed to transmit information through cable TV, or over-the-air broadcasts used in the NTSC (analog) standard.
W
Watt: A unit of power or energy. One horsepower is equal to 745.7 watts.
Watts: Measurement of amplifier power. Home amplifiers and receivers must be rated in watts per channel, or the amount of power the amp sends
to each speaker.
WebTV™: WebTV Networks, Inc. manufactures set-top boxes that allow users/viewers to access the Internet on their NTSC TV receivers.
Weight Categories To try to simplify choosing a projector we have divided our range into 5 weight categories:
Sub-micro - projectors less than 2 kilogrammes
Micro - projectors from 2 to 3 kilogrammes
Portable - projectors from 3 to 5 kilogrammes
Desktop - projectors from 5 to 12 kilogrammes
Installation - projectors greater than 12 kilogrammes
Wide Area Network (WAN) A computer network which usually spans larger geographic area, such as cities, counties, states, nations and planets.
WAN's usually employ telephone-type topologies, like T1, T2, T5, ATM, ect. The Internet is held together by lots of WAN's which hold together
LAN's, which network computers.
Widescreen: This format presents films in their original theatrical aspect ratios, or shape. Most theatrical movies are shot on film that is from 25
percent to 90 percent wider than a standard TV display. For example, a film shot in a 2.35:1 aspect ratio loses almost half the original picture when it
is cropped to fill your TV screen, which is 1.33:1. The black bars at the top and bottom of the screen are normal for this format. Even though the
image is smaller, you can actually see more of the picture. WIDESCREEN: Programs that are recorded and broadcast in the 16:9 format. In the
analog format, these programs are presented in the "letterbox" format. Widescreen: Term given to picture displays with a wider aspect ratio than
NTSC 4:3. Digital HDTV is 16:9 widescreen. Most motion pictures also have a widescreen aspect ratio, some even wider than 16:9. Widescreen
Video material produced in wider aspect ratio than the standard TV ratio (4:3, or 1.33:1) is commonly referred to as widescreen video. In general
anything with an aspect ratio above 1.66:1 can be considered widescreen. Widescreen material is presented on DVDs in either anamorphic or
letterboxed format. At times widescreen material is also cropped into 4:3 format using Pan & Scan. Widescreen - Term given to picture displays with
a wider aspect ratio than NTSC 4:3. Digital HDTV is 16:9 widescreen. Most motion pictures also have a widescreen aspect ratio, some even wider
than 16:9.
Window Box: Films with an aspect ratio more narrow than 16:9 will display black bars on the sides of the picture rather than the top and bottom.
Windows Media Name of a group of technologies developed by Microsoft. This umbrella includes Microsoft's Digital Rights Management tools,
Windows Media Video encoding technology and Windows Media Audio encoding technology. Not very surprising, but these products are not public
standards, but Microsoft's own varieties of open standards like MPEG-4.
Wireless Cable Uses microwaves frequencies to transmit programming to a small antenna at a subscribers home.
WMA This is a compression format developed by Microsoft* Corporation to be played in Windows Media Player. It achieves an even better sound
quality than MP3s, with a smaller file size. *Microsoft and its logo as well as Windows and Windows NT, Windows Media are trademarks or
registered trademarks of Microsoft Corporation of the U.S in both the United States and other countries. WMA: Windows Media Audio. An audio
compression format similar to MP3, but with digital rights management (copy protection and usage restrictions) built-in by Microsoft. WMA Full
description not available yet. WMA stands for Windows Media Audio. A proprietary audio format owned by Microsoft, part of Microsoft's Windows
Media technology.
WMF "Windows MetaFile". A standard introduced by Microsoft for the exchange of images between Windows applications. WMF files can store a
complete screen image along with the vector information needed to recreate it in one file.
WMV WMV stands for Windows Media Video -- developed and controlled by Microsoft. WMV is a generic name of Microsoft's video encoding
solutions and doesn't necessarily define the technology what it uses -- since version 7 (WMV7) Microsoft has used its own flavour of MPEG-4 video
encoding technology (not very surprising, it's not compatible with other MPEG-4 technologies..). DivX ;-) video format is originally based on hacked
WMV codec.
Woofer: A speaker driver designed to reproduce low frequencies.
Word Length: The sampling rate determines how often an analog wave is sampled; the word length determines the resolution of the sample. The
larger the word length, the more accurate the sample as a whole. A 16-bit word length (CD) allows 65,536 different level or volume steps that can be
chosen for each sample.
Wow-and-Flutter: A measurement of speed instability in analog equipment usually applied to cassette transports and turntables. Wow is slow-speed
variations, and flutter is fast-speed variations. Lower percentages are better
Wrapper See container.
WSXGA: WSXGA defines a class of SXGA displays with a width resolution sufficient to create an aspect ratio of 16:9. Resolution is defined by the
number of individual dots that a display uses to create an image. These dots are called pixels. A WSXGA display has 1920 to 1600 horizontal pixels
and 1080 to 900 vertical pixels respectively that are used to compose the image delivered by the projector.
WXGA: WXGA defines a class of XGA displays with a width resolution sufficient to create an aspect ratio of 16:9. Resolution is defined by the
number of individual dots that a display uses to create an image. These dots are called pixels. A WXGA display has 1366 to 1280 horizontal pixels
and 768 to 720 vertical pixels respectively that are used to compose the image delivered by the projector.
X
XCD New data CD format which uses CD Mode 2/XA to store data on CD. Basically you can fit more data on single CD than using regular Mode 1,
because Mode 2 doesn't use triple error correction like Mode 1 does. Mode 2 is normally used for VideoCDs and AudioCDs.
X-curve: An intentional roll-off in a theatrical system's playback response above ~2kHz at 3dB per octave. A modern convention (standardized
between 1975 and 1984) specified in ISO Bulletin 2969, it is measured at the rerecording position in a dubbing stage or two-thirds of the way back in
a movie theater. Pink noise should measure flat to 2kHz and then should roll-off above that. Home THX processors add this roll-off, when engaged,
so that a home video soundtrack will have the same response as it would in a theatrical setting.
XGA Abbreviation for eXtended Graphics Array. Resolution is 1024 x 768 pixels. One of the standard PC data display modes. XGA: XGA is used to
define a specific display resolution. Resolution is defined by the number of individual dots that a display uses to create an image. These dots are
called pixels. An XGA display has 1020 horizontal pixels and 768 vertical pixels giving a total display resolution of 783,360 individual pixels that are
used to compose the image delivered by a projector. XGA - Short for Extended Graphics Array. A high-resolution computer display standard
developed by IBM in 1990. XGA supports 65,536 colours at a screen resolution of 640 x 480 pixels and 256 colours at 1,024 x 768 pixels. The latest
XGA-2 offers 1,024 by 768 resolution in high colour and a higher-refresh rate than XGA.
X-over: see crossover
XSVCD XSVCD stands for eXtended SuperVideoCD. XSVCD is same for SVCD as XVCD is for VCD -- an unofficial hack for an existing format, in
this case, for SuperVideoCD. XSVCD is a regular SVCD disc, but instead of staying within SVCD bitrate limits, it pushes the bitrate limits up to the
same level as DVD-Video does, up to 9.8Mbit/sec. With XSVCD you can also use full PAL/NTSC resolution instead of SVCD's regular 480x576 /
480x480 resolution. XSVCD is based on the idea that if standalone DVD player supports SVCD discs, it can read the material from the disc and in
other hand, when DVD player supports regular DVD-Video discs, it must be able to read higher bitrates of MPEG-2 video as well (both, SVCD and
DVD-Video are based on MPEG-2 encoding, so it is the same chip that decodes both formats). XSVCD's cons include the fact that only very small
amount of video can be stored in one CD and the fact that some DVD players don't support it as it is a hack and not a real format.
XVCD XVCD stands for eXtended VideoCD. It is not a real format unlike VideoCD and SuperVideoCD are, but instead it is a hack/extension of
VideoCD format. Instead of using VideoCD's constant bitrate of 1150kbit/sec, the video can use up to 3,5Mbit/sec bitrate, providing better video
quality. Also the resolution can be higher than VideoCD's CIF resolution -- full PAL/NTSC resolution can be used instead.
The problem with XVCD is the fact that it is not a real standard and therefore only some standalone DVD player can play these discs. And of course
using higher bitrate causes the problem that one CD can contain less video and your movies end up taking more CDs (VCD uses 1,1Mbit/sec bitrate
and if you use 3,5MBit/sec, obviously the CD can only contain appx. 1/3 of the length VCD can -- average of 25 minutes per CD). See also XSVCD.
XviD Full description not available yet. An open source video codec project which was launched in 2001 to continue Project Mayo's open source
DivX codec. Basically a short piece of history is required in here to understand this fully. Original DivX ;-) codec was not developed from the scratch,
but was just a hacked version of Microsoft's WMV video codec. This version, best known as DivX ;-) v3.11 alpha (which was the last official version
of the hacked codec), quickly became ridiculously popular among videofreaks all over the world. After its success, group of people, most notably the
hacker behind the DivX ;-) codec, started developing a legal version of the codec which would be a real codec instead of basic hack of existing
Microsoft codec. They launched an open source project, dubbed as Project Mayo (also known as OpenDivX) to develop this codec. After a while the
codec matured, but the original developers wanted to push it further and started a company called DivXNetworks which started developing its own
closed source version, based on the work of the Project Mayo. Eventually this closed source codec was released as DivX 4 (since that, we've seen
this closed source version to develop further and currently, 04/2002, the latest version of the codec is called DivX 5.01). Now, open source guys
didn't want to abandon the work of the Project Mayo and they continued to develop the codec further and the XviD was born.
X-Windows An graphical input/output foundation used extensively on Unix systems. X doesn't provide a complete GUI but rather the input and
output control a GUI uses. This means that you can select from dozens of different desktop's if you're running Linux or Unix from Window's look-alikes to the outlandish - but very attractive - Enlightenment.
Y
Y/C: Abbreviation for luminance/ chrominance, aka S-video signal. Color and detail signals are kept separate, thus preventing composite video
artifacts. Cable uses four-pin connector. Used with S-VHS VCRs, DVD players, Hi-8, and DBS receivers.
YpbPr Component Video signal the same as YUV where Y = luminance; Pb = blue minus luminance; and Pr = red minus luminance. Y/Pb/Pr: See
component video.
Y-Splitter A cable or adaptor to enable single output into two inputs or a single input into two outputs.
YUV A modified form of the component RGB video signal. The black and white (luminance) part of the signal is removed from the red and blue and
added to the green. This gives greater detail to the picture, as the human eye perceives detail in green better than red or blue
Z
Zero Cells A phenomenon common to local market cable television ratings. The Nielson household metre indicates viewing, but the corresponding
diary data shows no record of viewing.
Zone: One or more rooms powered by one or more amplifiers, which are all fed by one source. A home can be divided into multiple zones, which
can play multiple sources, even though several rooms (say, the kitchen, dining room, and living room) all play the same source.
Zoom: Allows the user to get a close up image of far away subjects. In the optical range the image is magnified by the lens. In the digital range the
image is enlarged electronically.
Zoom LensSome - usually higher end - projectors come with a lens that allows adjustment of focal length (image distance compared with size)
instead of physically moving the projector.
Zoom Lens: A lens with a variable focal length providing the ability to adjust the size of the image on a screen by adjusting the zoom lens, instead of
having to move the projector closer or further.
Zoom Lens Ratio: Is the ratio between the smallest and largest image a lens can projector from a fixed distance. For example, a 1.4:1 zoom lens
ratio means that a 10 foot image without zoom would be a 14 foot image with full zoom. Conversely, a 10 foot diagonal image at 15 feet with no
zoom would still be a 10 image at 21 feet at maximum zoom (15 x 1.4 = 21 feet). A zoom lens is "not as bright" as a fixed lens, and the higher the
ratio, the less light output.
Zoom Microphone: This system incorporates four independent electret condenser microphones and is linked with the zoom operation of the lens,
so the microphones' directionality and sensitivity are adjusted as the zoom is activated. The directionality adjusts in 256 steps from wide to zoom, so
voices and sounds are recorded naturally and correspond with the images. Wide mode emphasises the stereophonic ambience, while zoom mode
narrows the recording direction to capture monaural-like sound from a distant subject.
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