DVD glossary
- s
One second of time.
- Sample
Value of an analog or continuous signal at a
single point of time (see Digitize.)
- Scanning Velocity
Linear velocity at which optical data features
pass a fixed point such as the pickup head of a drive.
- Scarlet Book
Proprietary Philips/Sony specification (scarlet
cover) for a Super Audio disc of one DVD layer and one CD layer.
- Section
CD information group containing 98 consecutive
frames of interleaved bytes from scrambled sectors, plus C1 and C2 CIRC,
subcode, and frame sync. Also referred to as a subcode block.
- Sector
Smallest addressable entity in the information
area that can be addressed independently of other addressable parts.
- Servomechanism
Electromechanical means of automatically
maintaining a desired state by sensing variations from that state, and then
correcting those variations by using very small amounts of power to control
much larger amounts of power.
- Session
Single recording event that creates a single
information area (lead-in - program area - lead-out.)
- Single Session
Single recording event resulting in one lead-in
(with TOC), program area, and lead-out for the entire disc.
- Skew
See deviation.
- Space
High reflectance feature of a recording layer
representing data that can be sensed by an optical system.
- Spindle
Mechanical means of coupling a disc to a
rotating device.
- Stamper
The electroformed part made from a mother and
containing a reversed data image of the final disc. Becomes part of a mold for
the injection molding replication process.
- Standard for Recording
A document agreed upon by the originator and
recipient of a volume specifying the recording and addressing methods for
information, including;
a unique physical address for each recorded
sector, and
the location of the data field within each
sector, and
the length of the data field within each
sector.
- Subcode
Ninety-eight-bit codes used in the CD format. P
and Q codes contain flag and control information. Codes R,S,T,U,V,W are
available and may be used for CD+G or other specialized applications.
- Subcode Block
See Section.
- Substrate
Transparent physical layer providing mechanical
support through which the laser can access an information layer.
- Sync
Unique bit pattern appended to and preceding
information that establishes a reference point for decoding of that subsequent
information.
- System Area
The first sixteen logical sectors in a CD volume
numbered 0 to 15.
S/PDIF
Sony/Philips Digital Interface. The standard for transmitting digital data (like
Dolby Digital) on consumer-grade components. Uses either a 75-ohm coaxial or
TOSLINK optical cable.
Sampling
Process of creating a digital representation of an analog signal. Standard CD
PCM is sampled at a rate of 44.1 kHz (44,100 "samples" of the sound are taken
per second).
Saturation
The amount of gray, as opposed to hue, in a color-the intensity of the hue.
Scanning velocity
Rate at which the laser pickup beam travels along the spiral track.
SCART
The standard European AV connector/socket for TVs, VCRs, and DVD players.
Scene
Access
You do not have to watch a DVD from beginning to end, or use fast forward and
rewind to access a particular scene. You may pick from a list of chapters to get
to a certain scene, which is usually accessed via the menu, or by pressing the
corresponding chapter number on the remote.
SDDS
Sony Dynamic Digital Sound. Sony's discrete multi-channel surround sound
available only in theaters. SDDS is available in 6-channel or 8-channel
varieties.
Seamless Branching
DVD has the capacity to switch instantaneously between separate and distinct
video, audio and subtitle "streams" or tracks. This is done via complex coding
commands, but unfortunately has not yet been widely exploited. (See also
Multiple Video Tracks, Multiple Audio Tracks and Subtitles)
Sector
Logical collection of bytes at the data layer (after de-interleaving). At the
physical layer, a sector consists of 38, 688 channel bits.
Sector
information
Header field providing the sector number.
Sector
number
A number that identifies the physical sector on a disc.
Sequence
MPEG definition of a set of coded pictures that are dependently coded. Within a
sequence, all pictures adhere to a common bitrate (CBR), buffer size, picture
size, aspect ratio, and frame rate.
Skip
Another DVD playback anomaly. See Jump.
Still
Gallery
DVD has the ability to display a single video frame at a time, for perfect still
images. (This is quickly noticeable when the pause button is pressed during
playback.) The best use of this capability is to take a collection of images and
allow the viewer to page through them with the remote control skip buttons.
Still frame files are generally used for behind-the-scenes photographs,
promotional artwork, storyboards or conceptual art. A DVD can easily hold
thousands of images or more.
Sub-picture
A simple picture intended to be superimposed over the video. Variable in display
size but bounded to CCIR 601 picture dimensions (720 x 480 for NTSC-rate
displays or 720 x 576 for PAL-rate displays).
Substrate
The clear material (polycarbonate) that surrounds and protects the stamped
information on a DVD. The substrate is thin and helps the DVD ensure greater
accuracy in the laser pick-up, because the laser is less likely to refract. It's
a DVD half-disc. Two substrates, each 0.6 mm thick, are bonded together to form
a 1.2 mm thick DVD disc.
Subtitles
A subtitle stream places text on the screen for the viewer to read, and is
essentially used for dialogue. Subtitles can be in any number of languages, So
that the viewer who does not speak the native language of the movie can view the
movie and read what the actors are saying. DVD allows for up to 32 subtitle
tracks. Closed Captioning is an extended form of subtitling, wherein additional
text is displayed with aural sound descriptions to aid hearing-impaired
individuals better understand action on screen. Note that a Closed Captioning
decoder is required to receive captioning encoded on a disc. However, by law all
new televisions must have built in Closed Captioning decoders.
Subwoofer
A speaker designed to reproduce bass (low frequencies). Bass is not very
directional, so most home cinema systems only need one mono bass channel.
Surround Speakers
Used in a ProLogic, Dolby Digital or other surround system. In a ProLogic system
there is typically 5 speakers; center, front left, front right, and rear left
and right carrying the same mono signal. In a Dolby Digital/DTS system the rear
speakers carry a stereo signal, and there is usually an additional subwoofer. It
is also possible to add additional subwoofers, dipole rear speakers and so on.
S-Video
Output
Unlike the RGB Component output, S-Video modulates the video signal in its
separate parts -- chrominance (color) and luminance (light and dark). This makes
for a more precise, detailed picture than RF.
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