Glossary - Sony Handycam DCR-DVD100 Technology Handbook

GLOSSARY

Bit Rate
The amount (measured in "bits") of data that flows in a
specified period of time. For video recording and playback,
which requires a large amount of data, bit rate is expressed in
Mbps ("megabits per second"). In general, a higher bit rate
results in higher-quality picture and sound. Bit rate can also
be constant or variable.
Coding
In a digital video or audio signal, coding (or encoding) refers
to the process of converting data from one form to another
-- for example, into a compressed form so more data can be
recorded and stored on a DVD disc. During playback, the
compressed data is decoded to its original form.
Constant Bit Rate
Constant Bit Rate (CBR) means that all scenes are converted
at the same rate; its purpose is to simplify the coding and
decoding process.
Dolby AC-3
The audio system used in DVD Handycam recordings. In the
Dolby AC-3 system, audio can be recorded in 2-channel
stereo, monophonic, or 5.1 channel surround sound (using
six speakers for front left/right, center, rear left/right, and
subwoofer). Audio compression only takes place in the
frequency range beyond human hearing.
DVD Applications
DVD is a multipurpose medium used for storing moving and
still images, audio and data. Its official name is "Digital
Versatile Disc." There are various applications for DVD discs,
including high-capacity storage of computer software and
data. DVD video applications include DVD-Video, used for
high-quality commercial recordings, and DVD-VR (Video
Recording), used for personal video recordings that can be
re-written (recorded more than once) and edited.
DVD Capacity
CD-sized DVD discs (4-3/4" or 12cm in diameter) can have
one or two sides, and each side can contain one or two
recordable layers. For a single-sided disc, dual-layer
recording allows for up to 8.5 GB of data. For a double-sided
disc, single-layer recording holds up to 9.4 GB. A double-
sided disc with two recording layers can hold up to 17 GB of
data. DVD Handycam camcorder use smaller 3-1/8" (8cm)
discs. A double-sided DVD Handycam disc has one recording
layer per side and holds up to 2.8 GB of data; it allows up to 2
hours of recording.
20 20
D V D H a n d y c a m T E C H N O L O G Y H A N D B O O K
DVD Formats
DVD discs for video recording exist in various formats or
standards. DVD-ROM is a playback-only format used for
commercial movies. DVD-R is a format that can be recorded
only once. DVD-RW can be recorded, edited and re-written
(re-recorded). DVD-RAM, DVD+R and DVD+RW are alternate
recordable formats not compatible with Sony DVD Handycam
camcorders, which use only discs that conform to DVD-R and
DVD-RW standards.
DVD-Video
The application for DVD recordings that do not require editing.
DVD-Video allows up to 2 hours of high quality moving
images and sound on a single disc, using MPEG 2 coding for
movies and Dolby AC-3 (Dolby Digital 2-Channel) or linear
PCM recording for sound. DVD-Video is an optical disc format
that also allows for special playback features such as multiple
screen ratios, captions, language options, and simultaneous
multi-angle viewing of a scene.
DVD-VR
The application for which Sony DVD Handycam camcorders
are designed. DVD-VR (or DVD Video Recording) provides
added in-camera capabilities such as re-recording, editing,
playlist display, etc.
Finalizing
Finalizing a disc enables its recorded contents to be played
back on other equipment. Once finalized, DVD-R and DVD-
RW discs are read as though they were commercial recorded
DVD movies -- allowing them to be played back on most DVD
players. A finalized disc can no longer be re-recorded, but
DVD-RW discs can be "unfinalized" to return them to
recordable state.
Groove/Land
On a DVD disc, "groove" describes the spiral field where data
is written to a recordable layer; "land" describes areas where
data is not written. In the case of DVD-ROM, reading is
carried out by an optical pickup following "pits" in the surface
of the disc. In the case of DVD-R and DVD-RW, reading is
carried out by an optical pickup following grooves in the
surface of the disc.
Initializing
Initializing a disc allows the disc to be recorded or written on.
Initializing a previously recorded disc will erase all existing
data on the disc. DVD-R discs to not need to be initialized.
DVD-RW discs must be initialized. The DVD Handycam
camcorder system provides an "initializing" prompt each time
a new DVD-RW disc is inserted.