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Glossary:
Table - YUV
Glossary of CD and DVD related
technical terms and abbreviations in alphabetical order. |
T
Table of Contents: Table of Contents of a CD, listing the start time
code of every track on the disc and contained in the subcode (Q-channel)
in the Lead In area. TAO:
Track At Once. Refers to the way some CD-Recorders write CD-R or CD-RW
discs, where a track (with post-gap) is written in one action, but then
waits before the next track is written. Each time the laser is stopped,
it writes Run-Out blocks. When re-starting, it writes Run-In blocks (a
total of 7 blocks). This can cause a glitch when playing audio CDs
recorded in this way, so other CD-Recorders use Disc at Once (DAO)
recording.
TCG: The DVD Forum's Technical Co-ordination Group, which comprises the
17 Steering Committee member companies and to which all the eight
working groups report. The TCG also submits technical proposals to the
Steering Committee.
Tilt: A measure of warping or dishing of an optical disc. Tilt is of
particular importance for DVD discs and must be kept within strict
limits.
Time Code: A frame-by-frame address code time reference recorded on the
spare track of videotape or inserted in the vertical blanking interval.
It is an eight-digit number encoding time in hours, minutes, seconds,
and video frames (e.g.: 02:04:48:16).
TOC: Table of Contents of CD, listing the start time code of every track
on the disc.
Track At Once: Refers to the way some CD-Recorders write CD-R or CD-RW
discs, where a track (with post-gap) is written in one action, but then
waits before the next track is written. Each time the laser is stopped,
it writes Run-Out blocks. When re-starting, it writes Run-In blocks (a
total of 7 blocks). This can cause a glitch when playing audio CDs
recorded in this way, so other CD-Recorders use Disc at Once (DAO)
recording.
Track Pitch: The distance between consecutive 'tracks' (ie series of
pits) on a CD or DVD
disc measured in a radial direction.
Tracks: Sub-divisions of the program area of a CD. Each disc may have up
to 99 tracks each at least 4 seconds in length. Each track can contain
data of only one type. Also refers to the sub-divisions of the audio on
a DVD-Audio disc, which may comprise up to 9 Groups each consisting of
up to 99 tracks.
TWG: Technical Working Group, which defined the original requirements
and specifications for DVD-ROM.
U
UDF: Universal Disk Format, the file system used for DVD and CD-RW
disks.
Unix: A multi-tasking operating system used in Sun workstations and
other computer systems.
UPC: Universal Product Code, a 13-digit catalogue number for the entire
disc contained in the disc's Table of Contents.
UV: Ultra violet light, used for curing the protective lacquer on CDs,
the bonding resin for DVDs and the inks used for printing labels on CD
and DVD discs.
V
Variable Bit Rate (VBR): Bit rate varies with time during the decoding
of a compressed bitstream. One example is MPEG-2 for DVD-Video where bit
rate changes according to compression requirements to keep the average bit
rate low. VBR encoding offers better quality than constant bit rate (CBR)
at lower data rates.
VBI: Vertical Blanking Interval, comprising lines at the start of
a TV signal before the picture area. These lines can contain Teletext,
Closed Caption (NTSC only) and other information.
Video CD: The White Book standard for up to 74 minutes of VHS quality
MPEG-1 video on one CD.
VOB: Video Object, a file on a DVD-Video disc containing MPEG video,
audio and navigation data.
Volume: According to the ISO 9660 standard, a single CD-ROM disc.
Volume Descriptors: Data (at the start of the program area of a CD-ROM
disc) containing file system information about the files and directories
on the disc. ISO 9660 and other file systems use volume descriptors.
VR: Video Recording mode defined by the DVD Forum for recording
video to re-writable DVD discs offering editing and other features. VR
recordings to DVD will not usually play on DVD players.
VSC: The Video Standards Council, established in 1989 as a non-profit
making body to develop and administer a Code of Practice designed to
promote high standards within the video industry and, from 1993, the
computer games Industry.
VTS: Video Title Set on a DVD-Video disc. There can be one or more
titles per DVD-Video disc.
W
WAV: File extension for PCM Wave audio files.
WG1: DVD Forum working group responsible for the DVD-Video
specification.
WG2: DVD Forum working group responsible for the DVD-ROM specification.
WG3: DVD Forum working group responsible for the File system specification
for DVD.
WG4: DVD Forum working group responsible for the DVD-Audio
specification.
WG5: DVD Forum working group responsible for the DVD-RAM
specification.
WG6: DVD Forum working group responsible for the DVD-R/RW
specification.
WG9: DVD Forum working group responsible for copy protection.
WG10: DVD Forum working group that is studying broadcast &
professional applications of DVD. WG11: A
new DVD Forum working group, formed in April 2002, to study technologies
for a new high definition DVD format.
White Book: Specification from Philips and Sony defining the Video CD
standard for up to 74 minutes of VHS quality MPEG-1 video on one CD.
WMA: Microsoft’s Windows Media Audio, an audio compression
format, offering higher quality than MP3 at the same bit rate, that is
supported by Microsoft’s Windows Media Player (WMP)and used, optionally,
in the second session of Midbar Tech’s CDS200 copy protected CD audios.
WMP: Microsoft’s Windows Media Player, which will play WMA,
MP3 audio files as well as Red Book CD tracks and video files. WMP is
used in Macrovision’s SafeAudio CD audio copy protection.
WORM: Write Once Read Many, known as CD-R (CD-Recordable).
X Xbox:
Microsoft’s games console, based on PC architecture.
XRCD: eXtended Resolution CD, developed by JVC to improve the
pre-mastering of audio for CD.
Y
Y: Common abbreviation for the luminance or luma signal.
Y/C Video: Type of video signal used in Hi8, S-VHS and some laserdisc
formats. It transmits luminance and colour portions separately, using
multiple wires.
Yellow Book: Specification from Philips & Sony defining the CD-ROM
specification.
YUV: A colour encoding scheme for natural pictures in which luminance
and chrominance are separate. The human eye is less sensitive to colour
variations than to intensity variations. YUV allows the encoding of
luminance (Y) information at full bandwidth and chrominance (UV)
information at reduced bandwidth.
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