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Glossary:
SACD - SVCD
Glossary of CD and DVD related
technical terms and abbreviations in alphabetical order. |
SACD: Super Audio CD, an alternative to the DVD-Audio format developed by
Philips and Sony. It is designed to play on audio CD players and Super
Audio CD players by comprising two layers: one with CD-Audio the other
with high quality audio. The audio encoding used is Direct Stream
Digital (DSD).
SafeAudio: a copy protection system for CD Audio discs developed
by Macrovision to prevent copying and piracy. SafeDisc: a copy protection
system for CD-ROM titles developed by C-dilla (now owned by
Macrovision) to prevent copying and piracy. It involves encrypting the
data and placing a signature on the disc that cannot be copied but must
be in place in order for the disc to be played.
Sampling: The first step in the process of converting an analogue signal
into a digital representation. This is accomplished by measuring the
value of the analogue signal at regular intervals called samples. These
values are then encoded to provide a digital representation of the
analogue signal
Sampling rate: The number of samples taken of a signal per unit time.
SAO: Session at once, where a complete session (Lead-in, Program and
Lead-out areas) of a CD-R or CD-RW disc is written in one uninterrupted
sequence.
Satellite: a loudspeaker, usually one of up to 5, which has a
limited bass response to reduce its size but is used with a subwoofer to
provide a full frequency range in a surround sound system.
Scanning Velocity: Velocity (speed) of a CD or DVD when being read at
normal speed. This should be constant from start to finish of the disc.
Scarlet Book: The book containing the specification for SACD,
Philips' and Sony's proposal for a next generation audio disc format.
SCMS: Serial Copy Management System, which is used to control the
copying of the content of a CD. Three possible conditions are defined:
1. No restrictions on copying
2. Single generation copy allowed
3. No further digital copying allowed
The SCMS flags are output from CD players via the S/PDIF which is used
to connect to a CD-recorder or other recording hardware. CD-recorders
should obey the SCMS flags, inhibiting copying from a second generation
copy or where no copying is allowed. SCMS has no affect on analogue
copying.
Screen Printing: A process used for printing multi-colour labels on CD
and DVD discs.
SD: Super Density Disc, Toshiba's original high-density compact disc
proposal.
SDDS: Sony Dynamic Digital Sound, introduced in August 1994, for the
film industry, designed to provide the best and highest quality sound
presentation. SDDS is an optional audio coding format for DVD-Video.
SECAM: "SEquential Couleur A Memoire" (sequential colour with
memory). Video format used in France, Eastern Europe and other
countries.
Sectors: Units of data on a CD-ROM of DVD-ROM disc containing 2048
bytes of
data plus header information.
SecuROM: A CD-ROM copy protection technology developed by Sony
and offered by Deluxe for protecting games and other CD-ROM
applications.
Session: An area of a multisession CD consisting of a Lead-In area,
Program area and a Lead-Out area. On a CD-R it allows the data to be
written a session at a time. Up to 99 sessions may be written to a
single disc.
SHG Laser: Second Harmonic Generation laser, for creating a laser output
with half the wavelength of the laser generating the light. This allows
an infrared laser to be used to generate blue light for higher density
optical discs.
Si: The chemical symbol for Silicon, used for the semi-reflective layer
of a dual layer DVD-9 disc as a lower cost alternative to Gold.
SID Code: A unique set of codes on Compact Discs to identify where it
was manufactured. The Mastering Code identifies the laser beam recorder
used to master the title and the Mould Code identifies which moulding
machine was used. SID Codes were introduced by the IFPI in conjunction
with Philips Electronics
SIF: Standard Interchange Format for video images of 240 lines with 352
pixels each for NTSC, and 288 lines by 352 pixels for PAL and SECAM.
SIIA: Software and Information Industry Association, which was formed on
1 Jan 1999 from the SPA (Software Publishing Association) and the IIA
(Information Industry Association).
SMART Content: System Managed Audio Resource Technique, used in
DVD-Audio discs and players to allow multi-channel audio to be
down-mixed to stereo exactly as the artist/producer intended.
SMPTE: Society of Motion Picture and Television Engineers.
SMPTE Time Code: An 80-bit standardised edit time code adopted by the
SMPTE.
SPA: Software Publishers' Association, which has joined up with the IIA
(Information Industry Association) to become the SIIA (Software and
Information Industry Association).
S/PDIF: Sony/Philips Digital InterFace, for transferring digital
audio from a CD to another device.
Sputtering: A process for coating moulded CDs with aluminium whereby an
aluminium target is bombarded with particles causing the aluminium to be
deposited on the CD surface. Sputtering is also used to deposit Gold or
Silicon on the semi-reflective layer of dual layer DVD-9 discs.
Stamper: A nickel disc created by electroforming from the mother and
used to mould CDs and DVDs.
Subcode: A separate low speed data channel on every CD. The subcode
comprises 8 channels. The P and Q channels are used to provide control
information for CD discs. The R to W channels are used for CD Graphics.
Subheader: Subheader is one of the fields in a mode 2 sector and is used
to describe the contents of the sector.
Subpicture: Overlay graphics image contained in a DVD-Video file for
subtitles, menu highlighting and other purposes.
Subwoofer: A loudspeaker designed for low frequencies to reproduce the
low frequencies from the .1 channel of 5.1 channel surround sound. Also
used with small satellite speakers to reproduce the non-directional low
frequencies.
Super Audio CD: An alternative to the DVD-Audio format developed by
Philips and Sony. It is designed to play on audio CD players and Super
Audio CD players by comprising two layers: one with CD-Audio the other
with high quality audio. The audio encoding used is Direct Stream
Digital (DSD).
Super Video CD (SVCD): An enhanced Video CD format, which uses variable
bit rate MPEG-2 encoding at a higher data rate then Video CD version 2.
It also includes an additional stereo audio channel or multi-channel
audio and subpictures. SVCD offers video quality and features closer to
DVD-Video, although a full-length movie will require three discs.
Surround sound: Multi-channel audio providing a two-dimensional sound
resulting from the use of loudspeakers at the front and rear. A typical
example is 5.1 channels (used in DVD-Video titles) comprising three
front and two rear channels plus a low frequency effects channel.
SVCD: Super Video CD, an enhanced Video CD format, which uses variable
bit rate MPEG-2 encoding at a higher data rate then Video CD version 2.
It also includes an additional stereo audio channel or multi-channel
audio and subpictures. SVCD offers video quality and features closer to
DVD-Video, although a full-length movie will require three discs.
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