Matakuliah
Tahun
: O0382 – Dasar-dasar Produksi Siaran Televisi
: 2010
VIDEO RECORDING AND STORAGE
SYSTEM
Pertemuan 9
Tape and Disk-Based Recording Systems (1/5)
Tape-based recording system uses videotape for the recording, storage,
and playback of video and audio information.
Disk-based recording system uses either large-capacity computer hard
disks or read/ write optical discs. This section will discuss aspects on
recording systems: (1) analog and digital systems, (2) linear and
nonlinear systems, (3) composite and component systems, and (4)
compression.
Analog and digital systems
The difference between analog and digital recording system is on the
way they store the recording. In analog recording systems, it records
video and audio signal as created and processed by the video source; in
digital recording systems, it stores not the video nor the audio signals,
but the data.
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Tape and Disk-Based Recording Systems (2/5)
Linear and nonlinear systems
The differences between linear and nonlinear recording systems are on
the way the information are recorded and accessed.
Linear systems apply to all tape-based systems. Linear system records
the information serially; therefore, the data retrieval should be in series.
Nonlinear systems apply to all disk-based systems. Nonlinear system
records the information randomly; therefore, the data retrieval can be
conducted in random access. Nonlinear or random access is important
when editing as the data can be recalled instantaneously.
Composite and component systems
The video recording in composite and component systems differs in
production application. Analog and digital systems can treat their signal
in four ways: (1) composite, (2) Y/C component, (3)Y/ color difference
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component, and (4) RGB component.
Tape and Disk-Based Recording Systems (3/5)
Composite system
The analog composite system combines the color (C, or
chrominance) and brightness (Y, or luminance) information into a single
(composite) signal. Composite signal is also called NTSC system since it
was standardized by the NTSC (National Television System Committee).
NTSC system is different from worldwide system (eg.: European PAL).
The major disadvantage of composite signal is that there can be
interference between chrominance and luminance that gets worse; and
more noticeable with each videotape generation.
Y/C component system
In the analog Y/C component system, the Y and C are kept
separate during the encoding (write) and decoding (read) process. During
recording process, both signals are combined and occupy the same track
on the videotape. The advantage of Y/C component system is that the
system produces higher-quality pictures that will suffer less in subsequent
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tape generations than do NTSC tapes.
Tape and Disk-Based Recording Systems (4/5)
Y/color difference component system
In the analog Y/color difference component system; the
luminance signal, the red signal minus its luminance (R-Y), and the blue
signal minus its luminance (B-Y) are transported and stored as three
separate signals.
RGB component system
In analog RGB component system, the red, greed, and blue
signals are kept separate and treated as separate component throughout
the recording and storage process.
Sampling
The 4:1:1 over 4:2:2 sampling ratios in all forms of video
recording mean in the digitizing process, the C (color) signals are each
sampled at one-fourth for 4:1:1 and one-half for 4:2:2 the sampling
frequency of the Y (luminance) signal.
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Tape and Disk-Based Recording Systems (5/5)
The luminance signal receives such privileged treatment because it is a
major contributor to the sharpness of the picture. As for color signal, it
produces good color for most normal production requirements.
If high-quality color that can stand up to a variety of special effects such as
various blue-screen or chrome-key effects is required, then the equipment
that uses a higher sampling ratio is needed.
Finally, we must understand that in comparison, the video signal of the
NTSC composite system is of lower quality than that of the Y/C component
system which is somewhat inferior to the Y/color difference component
system or the RGB component system.
Compression
In compression, there are (1) lossless compression which means
rearranging data so that it takes up less space, and (2) lossy compression
which means throwing away the unnecessary items so that it can use much
smaller suitcase. The 2 (two) compression standards are JPEG for
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compressing styli images and MPEG for compressing moving images.
Tape-Based Recording and Storage Systems (1/5)
This part will discuss 4 (four) aspects on tape-based recording and
storage systems: (1) how videotape recording works, (2) the operational
VTR controls, (3) their electronic features and how they function, and (4)
the major analog and digital VTR’s presently in use.
How videotape recording (VTR) works
VTR is any electronic recording device that records video and audio
signals in videotape for later playback or postproduction editing purpose.
There are 6 (six) components that take part in videotape recording
process: (1) record/ playback heads, (2) videotape tracks, (3) video track
that contain the picture information, (4) audio tracks that contain all sound
information, (5) control track that controls the videotape and rotation
speed of the VTR speed, (6) digital recording systems that translate the
video signal into digital form and record it as digital information. The final
record is no longer a video signal but on/off pulses that are usually coded
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as 0’s and 1’s.
Tape-Based Recording and Storage Systems (2/5)
Operational VTR controls
The most basic functions on VTR control are: (1) play, (2) stop, (3) record,
(4) fast-forward, (5) rewind, (6) eject buttons, and (7) audio volume
control. The more sophisticated VTR has additional functions: (1) standby,
(2) pause or still, (3) search or shuttle, (4) tracking, and (5) audio controls.
Electronic controls
The major electronic features that is important to understand to operate
VTR are: (1) input and output jack, (2) the time base corrector, (3) the
frame store synchronizer, (4) the automatic moisture shutdown.
Major Analog Videotape Recorders
The more popular tape-based analog VTRs found in many large and small
television stations and production centers include Betacam SP, S-VHS,
Hi8, and VHS. In the next slide, there will be breakdown of each
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characteristics of the major analog videotape recorders.
Tape-Based Recording and Storage Systems (3/5)
Analog VTR Table
System
Recording Format
Cassette
Production Characteristics
Betacam SP
Y/C component
Y/color difference
½ inch (12.65mm)
High quality, standard high-end analog
recording system in studio VTRs and
camcorders
S-VHS
Y/C component, but
actually recorded as a
composite signal
½ inch (12.65mm)
Good quality, downward compatible with
VHS
Hi8
Y/C componet
8mm (just slightly
more than ¼ inch)
Good first-generation quality, must be
dubbed up to a higher quality format for
extensive postproduction editing
VHS
NTSC composite
½ inch (12.65
mm)
Quality not good enough for broadcast
applications or extensive postproduction,
used extensively in off-line work.
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Tape-Based Recording and Storage Systems (4/5)
Major Digital Videotape Recorders
The advantages of digital VTRs are:
 More compact and even less expensive models produce high-quality
pictures and sound that maintain their quality through repeated dubs;
 Does not need to be converted for computer storage on hard disk for
nonlinear editing and special effect manipulation;
 Easy to operate
The major systems on major digital videotape recorders are: (1) DVCPRO,
(2) DVCam, (3) DV, and (4) Digital Betacam. In the next slide there will
be description on each characteristic of those systems.
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Tape-Based Recording and Storage Systems (5/5)
Digital Classification
Sistem
Recording Format
Sampling
Ratio
Cassette
Production Characteristics
D-1
RGB component
Y/color difference
component
4:4:4
4:2:2
¾ inch
(19mm)
Superior video and audio quality, still in use in
some postproduction houses for building
complex effects, tolerates many dubs with no
quality loss
D-2
NTSC composite
¾ inch
(19mm)
Can be integrated with analog equipment, no
compression
D-3
NTSC composite
½ inch
(12.65mm)
Same as D-2 except that it has a smaller tape
size. Can record up to 4 hours of programming,
no compression
D-5
RGB component
4:2:2
¼ inch
(6.35mm)
All four audio tracks are high-fidelity and
reproduce CD-quality sound. No compression in
standard TV, compressed in HDTV
D-7/
DVCPRO
Y/color difference
component
4:1:1
½ inch
(12.65mm)
Excellent quality, intraframe compression. The
higher-quality DVCPRO 50 uses 4:2:2 sampling
when interfaced.
D-9/ DigitalS
Y/color difference
component
4:2:2
½ inch
(12.65mm)
Compatible with other digital systems, plays
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back S-VHS tapes, intraframe compression.
Disk-Based Recording and Storage Systems (1/3)
The basis for nonlinear production editing is the development of largecapacity hard disks or read/write optical discs with fast access times.
The following will be the overview on all disk-based recording and
storage system related aspects: (1) hard disk systems, (2) read/ write
optical discs, and (3) methods of data transfer.
Hard Disk Systems
These systems include:
Large capacity hard disks
The accelerated hard-drive speeds and highly efficient
compression techniques makes it easier to store and retrieve digital
video and audio information for postproduction editing.
Portable hard disks
Also called fieldpacks, are designed to be docked with ENG/
EFP cameras. It has the size of a dockable VTR that can hold two hours
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digital video and audio information.
Disk-Based Recording and Storage Systems (2/3)
 Electronic still store (ESS) systems
ESS is a slide that stores any frame from various video sources
(camera, videotape, or computer) and those frames can be stored in a
hard disk. A tiny 2-inch floppy can hold up to 200 frames.
Digital video cart machines
Video cart machines record, manage, and automatically play back a
great variety of videocassettes. However, this huge machine has been
replaced by large-capacity computer systems.
Read/ Write Optical Discs
This system enables the recording and playing back a great amount of
digital information. For this purpose, we can use CD-Rs (compact disc
recordable) for storing information, and CD-RWs (digital versatile discread/write) for recording and playing back short or long video
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sequences.
Disk-Based Recording and Storage Systems (3/3)
The main advantage of read/write optical disc is its extremely fast
access time; and the ability to precisely locate, cue, and play a certain
scene in a second.
Data Transfer
There is a need to transfer the data recorded by the digital camcorder to
a temporary digital storage device. FireWire (from Apple) and i-link (from
Sony) are the data transfer system that able to transfer digital data from
storage (like camcorder VTR) to a desktop computer.
Similar to streaming audio, streaming video is an internet delivery
system that sends compressed data as a continuous stream and it can
update video continuously while you are watching the video.
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