11.4. Glossary
A
A-Roll/B-Roll
In analog editing, two reels of source footage (the A and B rolls) are used to
provide material for editing. The B roll may be a part or a whole copy of the A roll.
The two sources are then used to create video effects and transitions. In non-linear,
digital editing these terms are not generally used, since digitized clips of the original
footage can be duplicated, cut trimmed, and overlapped an unlimited number of
times.
A/V Drive
Hard drive that avoids thermal recalibration and thus avoids interrupting the flow
of information. This is sometimes referred to as "embedded servo." This is useful in
digital video, in which large amounts of image and audio information must pass
through the computer in realtime. Most new hard drives satisfy this requirement.
ADPCM
A compressed audio format developed by Microsoft. PCM stands for Pulse Code
Modulation.
AESEBUI
Digital audio transmission standards developed by the Audio Engineering Society
and European Broadcast Union. It specifies transmission of data in a stream that
encodes stereo audio signals along with optional information.
Aliasing
Aliasing is any unwanted result caused by a sampling rate lower than twice the
maximum frequency of the material being sampled. Because the object is not
sampled enough, it cannot be reproduced properly. Lines which are not filtered
properly, and look jagged rather than smooth, are an example of aliasing.
Alpha channel
The alpha channel is an 8-bit channel of information in certain image files such as
32-bit .tga files, which stores opacity and transparency values as greyscale values on
a scale of white (fully opaque) to black (fully transparent). The alpha channel is vital
in superimposing aspects of images, compositing, creating mattes, and colour
keying.
Analog signal
Storage or encoding of signal through the use of continuously varying voltages.
Electronic current that fluctuates smoothly in value (voltage amplitude) over time.
Anti-aliasing
Anti-aliasing removes or avoids the effects of aliasing by filtering more effectively.
Anti-aliasing smoothes rough edges and in sound removes artificial high frequency
"beats". This is particularly useful when your audio is being output to different
specifications than the original souce file. In audio, anti-aliasing is also known as
over sampling.
Artifact
Perceived degradation of an image through processing.
Aspect ratio
The ratio of width to height in a picture. Normal TV has an aspect ratio of 4 x 3 (or
1.33 to 1), widescreen TV - HDTV and widescreen PAL - (16 x 9) is 1.77 to 1.
Theatre screens generally have an aspect ratio of 1.85 to 1.
Audio editing
The act of mixing audio tracks with others and with video.
Audio levels
Measured in the VU meter, these show peak and average sound levels. In Speed
Razor's Composition and Batch Capture windows, you will see the VU meters. At
the default setting, levels need to be kept below 0dB to avoid oversaturation of
audio.
Audio mixing
Combining audio tracks. As in analog audio mixing, tools such as automatic gain
control, faders, and VU meters are built into Speed Razor.
Audio oversaturation
Audio volume levels that exceed the limits of safe digital playback. A snapping or
popping sound may result from oversaturated digital audio. Other terms used
include: audio clipping or peaking.
Audio quality
Quality is based on sampling rate, bit depth, and the analog portions of sound card
and system. 16-bit, 44.1 kHz is CD level quality and the standard quality for digital
audio editing.
Audio track
Horizontal line where audio is played in the lower area of the Composition
window. Tracks are numbered and infinite. You can layer as many audio tracks as
your hardware will allow.
AVI
Audio Video Interleave. File type created by Microsoft. AVI files are also called
Video for Windows files. It is a flexible file designed for storing and playing audio
and video information. AVI files have audio and video linked.
Axis (x, y, z)
In digital video effects, horizontal (x), vertical (y), and depth (z) axes. In Speed
Razor, the 3D DVE effect allows you to shift images along the z axis, or into 3D
space.
B
Bandwidth
Amount of information that can be passed in a given time. Large bandwidth is
needed to show sharp picture detail and is also a factor in the quality of recorded or
transmitted images.
Batch capture
Digitizing (or capturing) analog video using Speed Razor to control an outside
video deck. Also referred to as "deck control."
Betacam
Brand name of Sony broadcast quality 1/2 inch tape and recorders. It is an analog
component system that uses 1/2 inch cassette, and is the standard in news and low to
medium budget video productions. Betacam uses a BNC connector, which has four
plugs on the back and a half turn locking shell used with coaxial cable.
Bin
A Bin is the main tool for organizing all files in a project, and for storyboarding
video and audio items before placing these on the timeline. Use a Bin to store all
video, audio, effects, transitions, and other files imported or captured to your project.
Add, remove, split, duplicate, and replace items in the Bin at any time without
affecting original file information. (Note: "Bins" were called "Libraries" in previous
versions of Speed Razor. Speed Razor 2000 X allows for multiple bins in a single
project.)
Bios
Basic input/output system. Set of instructions in read only memory that controls
low level PC operations such as booting.
Bit
Binary digit. Basic unit of information in binary code. Bits are represented as 1
(on) or 0 (off). Digital video signal consists of information about light intensity and
colour, as represented by the numbers encoded in bits.
Bit rate (data rate)
A data transfer rate measured in bits per second rather than bytes per second. See
data transfer rate.
Black videotape
Formatting videotape with timecode.
Burned-in timecode
Timecode numbers that are superimposed on the picture, used for logging and
selecting material.
Byte
8 bits. The combination of 8 bits into 1 byte allows each byte to represent 256
possible values, or levels of grey between white and black.
C
Cache
The area of memory that improves performance by storing contents of frequently
accessed memory locations and their locations. A cache can speed up operations in a
computer with slow RAM access compared to its processor speed.
Capture card
Hardware that converts analog video into digital signals.
CCIR 601
The standard for digitizing component video. Also sometimes called D1 after the
VTR format that first used this signal.
CD-ROM
Compact Disc - Read Only Memory. Disc that contains information in digital form.
Character generator (CG)
Editing device that generates text. The Speed Razor CG plug-in is in-sync's high
performance, low cost, and versatile character generator for Speed Razor.
Chroma key
Process of overlaying one video signal over another by replacing a range of colours
with the second signal. Typically, the first picture is shot with a person or object
against a special, single colour background (key colour). The second picture is
inserted in place of the key colour. In Speed Razor, you can heighten or decrease the
threshold and blend of a key to enhance its quality using the Color Difference
Keying effect.
Chrominance
The colour part of a video signal, but not its brightness or luminance. Thus black
and white images have no chrominance.
Clip
A segment of sequential frames. Video or audio on the timeline.
Clip sequence
A sequence of clips that may be a series of still images, animation, audio, or a
digital video sequence.
Codec
Compression decompression schemes. Used to compress video to a manageable
size. Some compress by throwing out unnecessary information. Others use
algorithms to encode redundant information, reducing long series to one byte. One
example is Motion JPEG in which 21 MB of video data (about one second of
uncompressed video) may be compressed to 733 KB. See Compression.
Colour bars
Video pattern consisting of eight equal width colours, used to establish a proper
colour reference before recording and playback, and for adjustment purposes.
Colour space
Colour range of specified coordinates, such as RGG, Y, R-Y, B-Y, and Hue,
Saturation, Luminance (HSL).
Component
Recording signal for D1 quality video enhances quality over composite recording
by allowing two chominance channels, R-Y (Red minus luminance) and B-Y (Blue
minus luminance), along with signal brightness (Y). Green is represented from these
three signals. D1, MII, Betacam SP, and Betacam use component. RGB is also a
component signal. See Composite.
Composite
Encoding or recording of video information through one signal, combining
luminance and chrominance portions. Bandwidth is restricted, quality is not as high
as component.
Compositing
The layering of multiple pictures on top of each other to create the moving picture
equivalent to a collage, and often resulting in surreal combinations. Typically used in
movie and television special effects, this can be done in a variety of ways: painting,
retouching, rotoscoping, keying, matting digital effects, etc. A cutout or matte hold
back the background and allows the foreground picture to appear to be in the original
picture.
Compression (video)
The process of reducing the size of digital information, usually by removing
redundant information, "lossy compression," or rearranges it through algorithms
"lossless" compression. Uncompressed video takes up about 21 MB per second,
about 1.2 GB per minute. D1 quality can be maintained with a compression of
around 21 MB per second -- based on the conversion from RGB colour to YUV
(4:2:2) which is 4 parts luminance (brightness) per 2 chrominance (colour) parts.
RGB: 720 x 480 (NTSC: screen size in pixels x 3 (bytes per pixel) x 30 (frames per
second) = 31 MB per second. YUV: 720 x 480 (screen pixels) x 4 (bytes) x 2 (pixels)
= 21 MB per second. DV (4:1:1) = 15 MB/sec uncompressed "lossless" quality.
Contrast
Degree of difference between dark and light in an image.
D
D1
Digital video tape format using the ITU-R 601 standard to record 4:2:2 component
video on 19 mm tape. Currently the highest quality video tape format generally
available, uses component recording signal. The first digital video tape format, hence
D1.
D2
Digital video tape format using the 4 fsc method to record composite digital video.
Uses 19 mm tape and a cassette similar to D1, uses composite recording signal. The
second digital videotape format, hence D2.
Data transfer rate
The amount of data transported in a given amount of time. Data rate is one means
used to define the amount of compression used on a video signal. Uncompressed D1
has a bit rate of 21 MB per second. A regular 2 GB hard drive has a data transfer rate
of 3 - 6 MB per second. MPEG 1 has a bit rate to 150 K per second -- equal to that of
a CD-ROM drive speed.
Decibel (db)
A unit for expressing the ratio between two amounts of electronic or acoustic
signal power, used for measuring audio and video signals. Equal to 20 times the
common logarithm of the voltage or current ratio.
Deck control
See "Batch capture."
Dedicated hardware
Hardware and software built for a specific task, such as an effects accelerator card.
This can improve image processing speed 10 to 100 times.
Digital signal
A signal having only 2 logical values (0 or 1, off or on).
Digitizing
The act of taking analog video and converting it to digital form. In 8 bit digital
video there are 256 possible steps between maximum white and minimum black.
Dongle
Security device that came with previous versions of Speed Razor that you attached
to the computer.
Drop frame / non-drop frame timecode
Drop frame timecode vaporizes 2 frames worth of video timecode every minute in
order to match 29.97 frames per second (or 59.94 fields per second) NTSC standard.
When timecode as first developed, it was assumed that video would run at exactly 30
frames per second. However, colour television arrived at 29.97 frames per second.
This meant that over an hour's time there would be about a three and a half second
error -- about 110 frames. This resulted in a problem for broadcast television, that is
duration sensitive and the Society of Motion Picture and Television Engineers
(SMPTE) is developing drop frame timecode to solve the problem.
DV
Digital Video. Mini digital tape format having 500 lines horizontal resolution and
a 54 dB signal to noise ratio.
DVD
Digital video disk. DVD holds 4.7 GB or 135 minutes of high quality video,
compared to a CD-ROM at 650 MB storage.
DVE
Digital Video Effect. For example, Speed Razor's 3D DVE effect.
E
EDL
Edit Decision List: A list of edits (and relevant information) in a video project. An
EDL is created in an off-line editing session as an ASCII text-only file written in a
standard proprietary format (such as CMX 3400), and recorded to a formatted
floppy diskette. The EDL contains source video information, including: reel name,
timecode type, event number, source reel, edit mode, transitions, source and result
(or project) SMPTE In and Out points for video and audio. The list is then read by
online equipment used to produce the final high quality edit master tape. A "clean"
EDL accurately reflects the edits in a project. This EDL will not define any extra
frames not included in the edit. A "dirty" EDL includes extra sections of material,
before and after the pieces used in the final edit and so does not accurately reflect the
edit. A clean EDL is important for several reasons: a) It can be read: a necessity
when looking for shots or using the list for logging shorts. b) It is essential for online
assembly. c) A list must be clean if events are to be sorted.
Equalization
The use of filters or attenuators to adjust output levels in specified frequency
ranges.
F
Fibre channel
Network standard designed to replace both Ethernet and SCSI. Fibre channel
supports rates up to 125 MB per second (1000 Mbps), and over 64 devices per
segment.
Field
One half of a complete video picture (frame), containing all the odd or even
scanning lines of the picture. NTSC has 525 active lines of information, and shows
two interlaced fields of 262.5 lines each, which appear one after another. Because the
time is 1/30th of a second, the eye actually reads both at the same time.
FireWire
Single, six wire/lightweight cable that carries both data and power. Serial high
speed bus designed to replace SCSI. Found on Sony cameras. Can be used with up to
128 devices.
Frame
One complete video image -- usually comprised of two fields.
Frequency
Rate of steady vibration, pulse, or change measured in hertz (Hz) or cycles per
second. The frequency of alternating current in the United States is 60 Hz and the
frequency of alternating current in the United Kingdom is 50Hz.
G
Gain
The increase in signal provided by an amplifier between input and output level. It
may be positive, negative, or null (unity gain).
Garbage matte
See Matte.
Generation loss
Generation refers to a copy of analog video tape. Each generation adds more noise.
In digital, each layer of compression may degrade image quality. Speed Razor
maintains all source images to a composite in compressed form to avoid this.
Genlock
In capture, genlock syncs video signal to the deck, meaning the signal is slowed or
speeded to match the incoming signal.
Gigabyte (GB)
Approximately 1 billion bytes, or 1024 megabytes.
H
HDTV
High Definition Television. Screen aspect ratio is 16:9. Capable of producing much
higher detail than current broadcast systems.
I
IDE
Integrated Drive Electronics interface. Hard disk interface standard used for disks
in the range of 40 MB to 8.46 GB, requiring medium to fast data transfer rates. IDE
control is included with most motherboards.
In point
Point from which the video or audio clip is used in an edit.
Input source
In Speed Razor, the video clip that serves as the first source for a transition.
Interpolation
Another way of saying that the computer guesses the information that should be in
a given place based on surrounding information. In images, interpolation is based on
pixel colour. Audio interpolation is the sound equivalent.
IRQ
Interrupt Request lines. Hardware lines that carry signals from external devices to
the computer's processor. IRQs signal that an event has taken place requiring
processor attention.
ISDN
Integrated Services Digital Network. Allows computers to communicate over
existing telephone lines using a digital telephone network at much higher speeds than
are possible with an analog modem.
ITU-R 601 (CCIR601)
ITU-R 601 (formerly CCIR601) is a standard which defines broadcast quality
video and specifies how digital television should be encoded. The standard defines
encoding for 625 and 525 line systems. It usually refers to colour difference
component digital video, not RGB, although it could encompass RGB. This standard
sets out 4:2:2 sampling at 13.5 MHz with 720 luminance samples per active line.
Digitizing can take place in 8 or 10 bits. 13.5 MHz was selected because it works
equally well for the 625 and 525 line standards. Speed Razor adheres to broadcast
standards for video output.
J
Jog / Shuttle
In video editing, tool for viewing work to get exact frame location for editing.
Speed Razor's Composition and Item Info windows have jog / shuttles.
JPEG
Joint Photographic Experts Group. A standard for compressing still image files.
Uses a "lossy compression" method that results in some loss of original data.
K
Key frame
Key framing is a process of marking frames in a sequence to denote specified
movement. Frames between the key frames are interpolated based on a linear
calculation.
L
Lead In and Out
Extra frames in case you want them in capturing. This is "pre-roll."
Letterbox
Placing a wide screen image on a conventional TV by placing black bands at the
top and bottom of the screen. Speed Razor's Crop Image effect has preset letterbox
settings.
Library
See Bin.
Limiting
Automatic, gradual reduction of volume as it increases to avoid audio
oversaturation. Limiting performs a function similar to that of dynamic volume
(gain) control in analog audio. While the dynamic volume control would
automatically compensate for the difference between, for example, two speakers on a
live microphone, limiting lowers volume on sound in editing.
LTC timecode
Linear timecode is designed to be recorded on standard audio tapes. When
recorded to video, LTC is placed on one of the linear audio tracks of the video tape.
An advantage of LTC is that it can be easily played back over a wide speed range by
a stationary head. However, it cannot be displayed when the tape is stopped or
moving very slowly. Another limitation is that it occupies an audio track which
might otherwise be used as part of a project's soundtrack. LTC is the original
SMPTE timecode standard; older video tapes, if they contain timecode, are striped
with LTC. In audio only productions, LTC is normally used.
Luminance
The black and white, or brightness, or an image. A video signal is comprised of
luminance Y, chrominance (color information) C, and sync.
M
Markers
Points inserted on the timeline ruler that indicate instance to the editor, such as
significant cuts, scene changes, etc. Speed Razor's marker can be defined while a
video or audio clip is playing or added and moved at any time.
Matte
An image file, often created as a greyscale .bmp file, whose greyscale values are
used to combine two separate images for compositing. A matte is a shape imposed
on the video background through which you can view another video or still image. A
"garbage" matte is a drawn and movable shape that is often used to hide artifacts on
the original image.
Megabyte (MB)
One megabyte is equal to 1,024 kilobytes.
Megahertz (MHz)
A unit of frequency equal to 1 million cycles per second.
Motion JPEG
Video that is a sequence of JPEG images.
MPEG
Moving Picture Experts Group. A standard for compressing moving pictures.
MPEG 1 use3s a data rate of 1.2 Mbps (Mega Bits per Second), the speed of CDROM.
MPEG 2 supports much higher quality with a data rate (also called a bit rate)
of from 2 to 10 Mbps. MPEG 2 is the format most favoured for video on demand and
DVD.
Multimedia
Ability to combine audio, video, and other information with graphics, control,
storage and other features of computer-based systems. Applications include
presentation, editing, interactive learning, games, and conferencing.
N
Non-destructive editing
In digital video editing, "clips" that appear on screen are icons. While trimming,
cutting, and deleting clips from the Composition window in Speed Razor, the
original clip information is never destroyed.
Non-drop frame timecode
See Drop frame / non-drop frame timecode.
Non-linear (NLE)editing
Non-linear refers to random access capabilities for searching, recording and
playing back digital video sequences stored on the hard drive. Non-linear editing is
more efficient due to the elimination of search time associated with accessing video
clips from videotape. NLE allows you to reorganize clips or make changes to
sections without having to redo the entire production.
NTSC
National Television Standards Committee. The television and video standard in use
in the United States, Canada, Mexico, and Japan. Consists of 525 horizontal lines at
a field rate of 60 fields per second. (Two fields equal one complete frame). Only 486
of these lines are used for picture. Broadcast: 720 x 486 pixels. The rest are used for
sync or extra information such as VITC and Closed Captioning.
O
Off-line / On-line editing
Off-line editing is the process of producing a rough cut or EDL that will be passed
to another editing suite for final cut. On-line editing is the process of creating the
final high quality edit master tape. While cost may differ between the two processes,
what really distinguishes off-line and on-line editing processes is the editing intent.
in-sync Speed Razor is the all purpose, digital editing software that may be used for
on-line or off-line editing.
Out point
The end point of a trimmed clip.
Oversaturation
See Audio oversaturation.
P
PAL
Phase Alternating Line. The television and video standard in use in most of
Europe. Consists of 625 horizontal lines at a field rate of 50 fields per second. (Two
fields equal one complete frame). Only 576 of these lines are used for picture.
Broadcast: 720 x 576 pixels. The rest are used for sync or extra information such as
VITC and Closed Captioning.
PALplus
A widescreen (16 x 9) television standard in use in Europe that is compatible with
existing 4 x 3 TV sets. Non- 16 x 9 TVs show the picture in a letterbox form. While
its aspect ratio is the same as HDTV, it does not offer the same level of quality as
HDTV.
Pan
In audio, moving sound from one speaker to another. Pan can be set between left
and right speakers.
PCM
Pulse Code Modulation. Uncompressed audio format used to encode an analog
signal into digital data. Takes 8-bit sample at 4 kHz 80000x per second which
provide 16 k of data per second.
Pixel
Short for Picture Element. The basic unit from which a video or computer picture
is made. Essentially a dot with a given colour and brightness value. D1 images are
720 pixels wide by 486 high. NTSC images are 640 by 480 pixels.
Preview
View of an edit or capture before rendering or before capturing the clip. Speed
Razor allows you to shuttle preview an effect or transition on the computer monitor
and preview a clip before batch capturing.
Project
In Speed Razor, a project is a video production that contains: 1) Saved versions, or
workfiles, of your work. This includes pointers for the arrangement of items on the
Composition window timeline and in a Bin within specific workfiles. 2) Video,
audio, still images, effects, transitions, third party plug-ins or other files associated
with your project.
Q
Q factor
Quantization Factor. The Q factor measures how much video is compressed. For
most capture cards, the higher the Q factor, the better the quality of the captured
image. However, a higher Q factor allows for less file compression and requires
more disk space to store video. With certain video capture cards you have the option
of setting dynamic or automatic Q factors. When you select, dynamic, different Q
factors are used for each frame or field of video. An automatic setting usually means
that your video capture software will determine an appropriate Q factor for the video.
R
RAID
Redundant Array of Independent Disks. A group of hard drives combined with a
RAID controller, which causes them to act as one storage bin. A RAID may work as
a protective agent if one of the hard drives fails. The different RAID levels, 0
through 5, are such designed for specific use. The level you use depends on your
system and requirements. For video, levels 0 or 5 are the most likely.
RAM
Random Access Memory. Used for the operating system, application programs,
and processing data.
Raster
Pattern of parallel horizontal scanning lines, traced by a video monitor's electron
beam, making up a video image. A raster device manages an image as lines of dots,
such as a television set or computer monitor.
Rendering
The computing of an effect. Process in which the computer pulls up two frames of
source material to be used in creating the effect or transition.
Resolution
The amount of detail in an image. Higher resolution equals more detail. Also used
to describe the size of an image, usually in pixels. In video, generally referred to as
horizontal resolution and evaluated by establishing number of horizontal lines clearly
discernible on a test pattern.
Result timecode
Result timecode (also called "Project" timecode) refers to a video clip's position on
the Composition window timeline. The result In and Out points indicate a clip's start
and end points on the timeline.
RGB
Red, Green, Blue. The primary colors of light. Computers and some analog
component devices use separate red, green, and blue colour channels to keep the full
bandwidth and therefore the highest quality picture. RGB is a type of video signal
that provides separate channels for output for paint systems and computers. An
extremely high quality signal, but for recording, is transformed into component or
composite signal.
RS-422
Serial data transmission standard used with VTRs.
S
S-VHS
S-Video. A higher quality than the original VHS tape. Uses S-VHS connectors,
which have a round plug with four pins. Composite signal in which the C
(chrominance) signal has been separated from Y for better colour, a step up from
basic composite video.
Scrubbing
Replay of video or audio tracks at various speeds or by "manually dragging the
job/shuttle bar in Speed Razor's Composition or Item Info windows.
SCSI
Small Computer System Interface. High speed (up to 40 MB per second) parallel
interface that can connect up to 15 devices at a time. Often used to connect hard
disks, tape drives, CD-ROM drives, and other mass storage media. There are four
main types of SCSI drives. Fast (10 MB per second), Fast Wide (20 MB per second),
Ultra (20 MB per second), and Ultra Wide (40 MB per second). Fast and Ultra are 8
bit and share the same type of connector; Fast Wide and Ultra Wide are 16 bit and
share another connector type.
Secam
French Video Sequential Couleur Avec Memoire. 625 lines / 25 frames per second.
Serial port
Computer input/output port supporting serial communications, in which
information is transmitted one bit at a time. Referred to as "COM port."
SMPTE timecode
SMPTE timecode was developed by the Society of Motion Picture and Television
Engineers as a standard to locate exact points on videotape. This is very helpful for
editing video because such a standard affords the ability to specify exact In and Out
points in video. The format of SMPTE timecode is HH:MM:SS:FF (hours, minutes,
seconds, frames). Many video decks and cameras now keep track of this timecode
and usually display on a readout on the deck itself. Also, many of today's cameras
record timecode onto the tapes themselves in an area of the tape not used for video or
audio storage. Since many decks also transmit this timecode through RS-242 ports,
Speed Razor can capture this information and attach it to the video inside the
program. There are two types of SMPTE timecode: drop frame and non-drop frame,
and two basic ways of storing timecode information: LTC and VITC.
Source timecode
Source timecode in Speed Razor is a video clip's individual timecode. If a clip has
not been trimmed, this timecode will start at zero and end at the clip's length (if not
imported from tape). Since source In and Out points for a clip relate specifically to
the clip, moving a clip on the Composition window timeline does not affect it.
Straight cut
A straight cut is one video clip following another without any transition. In Speed
Razor, this is viewed as one clip next to another on a track.
Sync
A term used in electronics to describe the precise alignment of two signals or
functions. Electronic pulses that synchronize the scanning of various video
equipment. In video, sync is an essential element for maintaining the proper clocking
of video signals.
T
Terabyte
One terabyte is equal to 1,024 gigabytes.
Timecode
A digital code number recorded onto a videotape for editing purposes. When
decoded, the code identifies every frame of a videotape using digits reading hours:
minutes: seconds: frames. See SMPTE timecode; Drop frame / non-drop frame
timecode; LTC timecode; VITC timecode; Burned-in timecode; Result timecode;
and Source timecode.
Transitions
An effect which allows a passage from one scene to another. Transitions must be
rendered.
V
VBR
Variable bit rate.
VHS
Video Home System. 1/2" consumer video cassette recorder and tape. Uses an
RCA connector, which records composite video.
Video capture card
Hardware that converts analog video into digital signals. New cards are capable of
realtime processing of video effects. Most current cards capture in fields (30 fps = 60
fields per second) for high quality.
Video track
A horizontal line where video clips, transitions, and effects are placed in the upper
area of Speed Razor's Composition window.
Virtual editing
Term used to describe Speed Razor's feature for editing without actual clips. When
working from an EDL or a tight storyboard, virtual clips can be assembled. When
the actual clips are brought into Speed Razor, they go to their assigned positions on
the timeline.
Virtual memory
Memory management allowing information in physical memory to be swapped out
to a hard disk, and allowing more memory space for application programs.
VITC timecode
Vertical Interval Timecode is recorded within the video picture, during the vertical
blanking interval. It can be present in a video signal without being visible on screen.
Compared to LTC, VITC offers two advantages for video editing: It can be read
from a still frame; and it provides field-rate (half-frame) accuracy. VITC cannot be
recorded on linear audio tracks.
VTR
Video Tape Recorder.
VU (Volume Unit) meter
Indicates peak and average levels of audio, and aids in preventing audio
oversaturation, volume exceeding the limits of digital playback -- during capture,
editing, and output.
Y
Y, Cr, Cb
Digital luminance and colour difference signals in ITU-R 601 coding. Cr is a
digitized version of R-Y, Cb is a digitized version of B-Y.
Y/C
Term used to describe the separation of video signal components used in systems
such as Hi-8 and S-VHS, and 8 millimeter recordings. In addition to composite and
component formats of colour recording, Y/C is used to record video signal.
YUV
A video system employing luminance and two chroma components directly to the
red and blue components.