Glossary
about Compact Disc
Appendable
Disc
An
open multisession disc. A readable disc that can have additional
data (sessions) written to it.
Bit
A binary digit, either zero or one.
Byte
A byte is made up of 8 bits. It represents one character
of information. A kilobyte (K) is approximately 1000 bytes.
A megabyte is approximately 1,000,000 bytes.
Buffer
A portion of memory that is reserved to hold data temporarily
before it is transferred to the CD recorder.
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CD-DA
This stands for Compact Disc Digital Audio. A CD-DA
disc conforms to the Red Book standard.
CD-R
This stands for Compact Disc Recordable. These discs
are writable with a CD writer drive and either a PC or Macintosh
computer.
CD-ROM
This stands for Compact Disc Read Only Memory. A CD-ROM
conforms to the Yellow Book standard. The data stored on it
can be either in the form of audio, computer or video files.
CD-ROM
Mode 1 & 2
The Yellow Book specifies two types of tracks, Mode
1 and Mode 2. Mode 1 is used for computer data and text and
has an extra error correction layer. Mode 2 is for audio and
video data and has no extra correction layer. CD-ROM/XA An expansion
of the CD-ROM Mode 2 format that allows both computer and audio/video
to be mixed in the same track.
Closed
Disc
Also called "non-appendable". Once a disc
is closed no further data can be added to the disc.
Close
Session
This prevents further data from being added to the
disc. This also stores file and directory information to the
Table of Contents.
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Data
Factual information such as sound, images, text, and
numbers in a form that can be processed by a computer.
Disc
at Once
A CD-ROM disc that the data is written in a single
session and the Table of Contents is written before the data.
HFS
Hierarchical File System - used by the Macintosh system
for storing files.
Hybrid
Generally a CD-ROM that contains both ISO 9600 and
Macintosh (HFS) files.
ISO
9600
The international standard for CD-ROM file format.
Joliet
Joliet is
an extension of the ISO 9660 standard, developed by Microsoft
for Windows 95 and Windows NT, to allow CDs to be recorded using
long filenames. It also allows for using the Unicode international
character set. For files recorded to CD, Joliet allows using
filenames up to 64 characters in length, including spaces. Joliet
also records the associated DOS-standard name for each file
so that the disc may be read on DOS systems or earlier versions
of Windows. [As in Windows 95/98, file and folder names up to
256 characters long, which may include spaces, are allowed.
To maintain DOS compatibility, a DOS-standard (8+3) filename
is associated with each file; these names are created automatically
by Windows 95/98 and can be viewed in Properties for each file.
To create these DOS-standard names, long filenames are truncated
and the tilde (~) is added; a number may also be added to distinguish
between files].
Mixed-Mode
A CD that contains tracks of differing formats. Most
often this term refers to discs that contain both computer data
(Yellow Book) and audio (Red Book) tracks. The data is on the
first track and the audio is on the following tracks.
Multisession
A way of writing to a CD that allows more data to
be added to readable discs at a later time.
MP3
A format for storing CD quality audio. This format
is a heavily compressed audio signal with a 10:1 ratio of compression,
while retaining its CD quality.
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Open
Disc
A CD that can accept additional tracks or sessions.
SCSI This stands for Small Computer System Interface. A SCSI
controller can support up to seven (7) devices(hard drives,
CD recorders and scanners). Each SCSI device in a chain must
have a unique ID number. Sector The information stored on a
CD is in sectors or blocks; each sector contains 2,048 bytes
(Mode 1) or 2336 bytes (Mode 2).
Session
A fully readable complete recording that contains one
or more tracks of computer data or audio on a CD.
Simulate
Write
A program that allows your CD writer to simulate the
writing to a disc with-out actually writing data. This is used
to test the hardware and file structure for errors.
Terminator A SCSI device that is required at the end of a SCSI
chain. TOC This stands for Table of Contents. On a CD disc it
is used by the computer or CD player to locate the information
on the CD.
Super
VCD
Super Video CD (SVCD) is an enhancement to Video CD that was
developed by a Chinese government-backed committee of manufacturers
and researchers. The final SVCD spec was announced in September
1998, winning out over C-Cube's China Video CD (CVD) and HQ-VCD.
In terms of video and audio quality, SVCD is in between Video
CD and DVD, using a 2x CD drive to support 2.2 Mbps VBR MPEG-2
video (at 480x480 (NSTC) or 480x576 (PAL) resolution) and 2-channel
MPEG-2 Layer II audio.
Track
A particular amount of data written on a CD. The size
of a track can vary from a few kilobytes to the whole contents
of the CD.
Track
at Once
A technique of writing to a CD disc where individual
tracks are written separately and the Table of Contents is written
after the data. The disc is not readable until "closed"
(i.e. Table of Contents is written).
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Video
CD
Similar to
an audio CD, a Video CD disc has a capacity of about 70 minutes
of video. It contains several tracks. The first track is a standard
ISO 9660 data track containing files which tell the VideoCD
player how to locate and play the other tracks on the disc.
It may also store still pictures, playlists, and menus. The
menus allow the user to select from various tracks or "scenes"
to play. Playlists can present the various tracks in different
orders. The other tracks on the disc are one or more audio/video
tracks, which may be followed by one or more standard CD-DA
audio tracks. The audio/video tracks use MPEG-1 compression
which compresses the video by a factor of approx. 60 to one.
VCD resolution
is 352x288 for PAL and 352x240 for NTSC. When playing PAL VCDs,
most NTSC DVD players and Video CD players, such as the Panasonic
and RCA players, deal with the difference is to chop off the
extra lines. The Sony NTSC players scale all 288 lines to fit.
Because PAL VCDs are encoded for 25 fps playback of 24 fps film,
there is usually a 4% speedup. Playing time is shorter, and
the audio is shifted up in pitch unless it was digitally processed
before encoding to shift the pitch back to normal.
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