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Glossary:
Caddy - CYMK
Glossary of CD and DVD related
technical terms and abbreviations in alphabetical order. |
Cactus Data Shield: A CD audio copy protection technology
developed by the Israeli company Midbar Tech. Two versions are
available, CDS-100 and CDS-200, the latter including a second CD-ROM
session containing compressed audio files, which play on a PC. Midbar
Tech was acquired by Macrovision in December 2002 and new CD copy
protection systems will comprise the best of the two companies’
technologies.
Caddy: Required to hold a CD or CD-R before it is loaded into
some CD-ROM drives or CD recorders.
CAV: Constant angular velocity where the rotational speed
remains constant. This mode is used in laserdics for interactive
applications. (see CLV)
CBR: Constant Bit Rate for MPEG-2 video encoding.
CCA: DVD Copy Control Association which administers the CSS copy
protection for DVD-Video and distributes keys to licensees.
 CCCD: Copy-Control CD, used to identify
copy protected CDs in Japan. A logo on the outer packaging of such CDs
is used to identify them.
CCI: Copy Control Information, for example
used by CPPM on a DVD-Audio disc and containing a number
of parameters defining what if any copies can be made. These include
Copy Permission, Sound Quality, Related Content and Transaction. The
parameters define how many generations of copy at the specified quality
and with the access constraints held elsewhere and pointed to by the
Transaction Parameter.
CCITT: Comité Consultatif Internationale de Telegraphique et
Telephonique or Consultative Committee on International Telephone and
Telegraphy, now known as the ITU-T (International Telecommunications
Union - Telecommunication Standardisation Sector). It is the primary
international body for fostering co-operative standards for
telecommunications equipment and systems.
CD: Abbreviation for Compact disc.
CD TEXT: A recent addition to the CD audio specification
allowing disc and track related information to be added to standard
audio CDs for playback on suitably equipped CD audio players. The CD
TEXT information, coded as characters for maximum efficiency, is
contained in the R to W subcode channels in the lead-in and/or program
area of a CD. CD TEXT is compatible with the ITTS (Interactive Text
Transmission System) standard. CD TEXT equipped players can provide a
range of display formats from one or two line, 20 character display to
21 lines of 40 colour alphanumeric or graphics characters. The
specification also allows for the future addition of additional data
such as JPEG coded images.
CD-EXTRA: Alternative name for Enhanced Music CDs, which are multisession CDs comprising a CD Audio session (with up to 98 tracks)
followed by a single-track CD-ROM XA session, which contains the data.
CD-EXTRA discs are compatible with all CD audio players (as the data
session is not seen) and the data track can be played in a Windows 95 or
98 PC and/or a Macintosh depending on how the software was written.
CD-G/CD-Graphics: CD Graphics using the subcode channels R to
W on an
audio CD.
CD-i: Compact Disc interactive (CD-i), a multimedia standard
introduced by Philips in 1987. The standard covers both disc and player.
Approximately 1m CD-i players have been sold worldwide, but, now only
used for some education and training applications.
CD-i Bridge: A bridge standard allowing CD-ROM XA discs to
play on CD-i players.
CD-i Ready: CDs that can be played on audio players (audio
only) and CD-i players (CD-i data & audio)
CD-R, CD-Recordables: Recordable CD used where small quantities are
required. CD-Rs allow data to be written either once only or in sessions
for a multisession disc. This allows the data to be updated and/or added
to until the disc is full. The data on a CD-R disc cannot be erased or
re-written, hence their alternative name WORM (Write Once Read Many)
disc.
CD-ROM: Compact Disc Read Only Memory, a compact disc used for
storing computer data and for multimedia and games applications. Data is
stored in sectors of 2048 bytes. The CD-ROM specification is contained
in the Yellow Book.
CD-ROM XA, CD-XA: Compact Disc Read Only Memory Extended
Architecture, a version of CD-ROM disc where data is stored in sectors
of 2048 bytes (with error correction) or 2324 bytes (without error
correction). Sectors also include a subheader, which contains
information to describe the contents of the sector. CD-I, Video CD,
Photo CD and CD EXTRA discs are based on the CD-ROM XA specification.
The CD-ROM XA specification is contained in an extension to the Yellow
Book.
CD-RTOS: Compact Disc - Real Time Operating System for CD-i
Players.
CD-RW: CD-ReWritable disc, which can be written to and
re-written a large number of times.
CD-Video/CD-V: Compact Disc - Video; CD audio with analogue
video. This format was launched on the market in 1988 but has not been
successful. CD-V discs should not be confused with Video CDs, which
contain up to 74 minutes of digital video on a compact disc.
CD-XA: See CD-ROM XA.
CDDA: Compact Disc Digital Audio, defined in the Red Book.
CDS: Cactus Data Shield, a CD audio copy protection technology
developed by the Israeli company Midbar Tech. Two versions are
available, CDS100 and CDS200, the latter including a second CD-ROM
session containing compressed audio files, which play on a PC. Midbar
Tech was acquired by Macrovision in December 2002 and new CD copy
protection systems will comprise the best of the two companies’
technologies.
CEMA: Consumer Electronics Manufacturers Association.
CGMS: Copy Generation Management System, a method for controlling
copying of DVD-Video discs. It allows only a first-generation copy to be
made. The player embeds information such as "Copy free," "First
generation only OK" or "Copy not possible" in the playback signal and
outputs it together with the latter, and the recorder detects it.
Chapter: Subdivisions of a video title (eg movie) on a DVD-Video disc,
each chapter being a scene or other section as defined during authoring.
Chroma, Chrominance: The colour portion of the video signal that
includes colour information. The luminance or intensity information is
coded in a separate part of the signal. The decoder will combine the
colour and intensity information and create the red, green and blue
signals that are needed to define the picture to be displayed.
CIRC: Cross Interleaved Read-Solomon Code used on every CD for error
correction.
Closed Captions: Text encoded in a NTSC TV signal for display on
a TV under user control. Closed caption data are contained in the MPEG-2
stream of a NTSC DVD disc and passed to the TV in the vertical blanking
interval (VBI) of the video signal.
CLV: Constant Linear Velocity, ie a constant speed in metres/second used
for reading the data on CDs. This contrasts with constant Angular
Velocity (CAV) where the rotation speed is constant. Laserdiscs can be
either CLV or CAV, but CLV versions have longer playing times than CAV
discs.
CMF: Cutting Master Format, which is a protocol, similar to DDP, that
describes data that will be recorded onto an optical disc and allows the
use of DVD-R for Authoring media instead of the more usual DLT. A single
DVD-R disc can therefore serve as both a check disc for testing and for
input to glass mastering. The CMF is written to the lead-in area. Titles
that require CSS encryption, CGMS or region coding cannot currently be
used with CMF.
CMYK: Cyan-Magenta-Yellow-Black (colour model for colour printing)
Codec: Coder/decoder; device or software that encodes and decodes
digital information.
Colorstripe: Part of Macrovision’s Analogue Copy Protection (ACP)
for DVD-Video, which makes recordings on VHS very distorted and
unviewable.
 Colour Palette: A table of colour values used to reduce the data per
pixel for encoding graphics images. For example a palette of 256 colours
can be programmed to any set of 256 colours from, say, a total of 16
million and therefore each pixel is represented by only 8 bits.
Component Video: A method for coding video signals as three separate
components, normally YUV or RGB.
Composite Video: A video format that combines chrominance (colour),
luminance (brightness) and blanking in one signal, rather than the
component parts.
Compression: The conversion of data to a more compact form for storage
or transmission. Compression can be lossy (used where there is redundant
information in the original data) or lossless (where the original data
can be recovered in its entirety).
Copy Protection: A technique used on CD and DVD discs to prevent the
contents being copied and/or re-used. Technologies used include
watermarking, signatures on disc and encryption.
CPPM: Content Copy Protection for Pre-recorded Media, developed by the
4C consortium comprising IBM, Intel, Matsushita and Toshiba. CPPM is the
digital copy protection system used for DVD-Audio discs and provides
more protection than CSS does for DVD-Video. For example it allows a
hacked playback device to be revoked through the use of a Media Key
Block (MKB) containing a different key for every model of playback
device instead of a single key.
CPRM: Content Copy Protection for Recordable Media, developed by the 4C
consortium comprising IBM, Intel, Matsushita and Toshiba. CPRM was
developed for recordable DVD discs and ensures that DVD discs cannot be
copied unless it is permitted by the content owner. In particular a
first generation copy cannot be further copied. It uses some of the
methods used for CPPM, but each individual disc is uniquely identified.
CPTWG: The Copy Protection Technical Working Group, an unofficial
industry panel recommending copy protection techniques for the DVD Forum.
CRC: Cyclic Redundancy Check used to check whether a data stream has
suffered any corruption producing errors.
CSS: Content Scrambling System, used for digital copy protection of
DVD-Video discs. CSS involves scrambling the video and audio data using
keys, which are stored in encrypted form on the disc. CSS scrambling is
normally carried out during glass mastering.
CYMK: Cyan-Yellow-Magenta-Black (colour model for printing)
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