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References
Analog Audio
Analog audio is a standard method of
recording audio used on all laser discs.
CAV (Standard Play)
A video recording system is used where
signals are recorded on the disc one frame
(picture) per disc revolution, and the disc
is played at a fixed rotational speed (CAV
= Constant Angular Velocity) of 1,800 rpm
(revolutions per minute).
This system is well suited for frame-by-
frame playback and variable-speed
playback. One side of a CAV disc can
have a playback time of up to 30 minutes
(for a 12-inch disc), which is equivalent to
54,000 individual frames. Each frame –
from frame 1 to frame 54,000 – is encoded
with its frame number. Playback time
varies according to the contents of the
disc.
CLV (Extended Play)
A video recording system where signals
are recorded on the disc at a Constant
Linear Velocity (CLV), and the rotational
speed during playback varies from 1,800
rpm (revolutions per minute) for the
innermost track to 600 rpm for the
outermost track. As a result, one side of a
CLV disc can have a playback time of up
to 60 minutes (for a 12-inch disc), which is
twice as long as a standard play (CAV)
disc.
CLV discs are encoded with time numbers
which correspond to the elapsed playback
time from the beginning of the disc.
Playback time varies according to the
contents of the disc.
Chapter Number
Some discs have chapter numbers used to
indicate the boundaries of sections on the
disc – similar to the chapters in a book. If
chapter numbers are recorded on a disc, it
will be indicated on the disc’s jacket. The
chapter search feature uses chapter
numbers to locate a certain chapter on the
disc.
Digital Audio
Digital audio is a method of recording
audio that is used on CDs, CDVs, and
laser discs in addition to the analog
audio. Digital audio provides wider
dynamic range and less distortion for a
more accurate reproduction of the
actual sound.
Frame Number
Frame numbers are the numbers
assigned to each picture frame on a
CAV (standard play) laser disc. The
frame search feature uses numbers to
locate a certain frame on the disc.
Time Number
Time numbers indicate the actual time
elapsed from the beginning of a CLV
(extended play) laser disc. The time
search feature uses the time number to
locate a certain place on the disc.
Track Number
Track numbers indicate the boundaries
of the sections (or tracks) on a compact
disc or compact disc with video. Track
numbers are assigned consistently
throughout the audio and video
portions of a disc. The track search
feature uses numbers to locate certain
tracks on the disc.
TOC (Table of Contents)
Compact discs (CDs), compact discs
with video (CDVs), and selected laser
discs (LDs) are provided with a section
called TOC at the beginning of the disc.
The TOC section is similar to the table
of contents of a book. It contains
information on the contents (number of
chapters, tracks, playing time, etc.) of
the disc.
Glossary
