Grass Valley Performer-HD - Manual (Page 56)

Glossary-2 Performer-HD Instruction Manual
Deserializer
A device that converts serial digital infor-
mation to parallel.
Digital
Use of discrete signal levels that corre-
spond to logic 1 or 0 to convey informa-
tion.
Digital Television (DTV)
The digital television broadcasting system
that replaces analog television. DTV in-
cludes both HDTV and SDTV broadcast in
digital form using MPEG-2 compression
for video, AC-3 compression for multi-
channel audio, and 8-VSB modulation for
digital terrestrial transmission.
Field
One scan of an interlaced video image. In
interlace systems (1080i, for example) two
fields are required to make a complete pic-
ture (video frame) because alternate lines
are scanned. Note that on progressive sys-
tems (720p, for example), one scan con-
tains all the image information, and so this
single scan is called a frame rather than a
field.
Field Replaceable Units
Components of a frame, matrix, switcher,
etc. that can be removed and replaced with
a spare. Field Replaceable Units are not re-
paired in the field and are sent to designat-
ed repair depots.
Frame
One complete scan of a video image. For
progressive video, all the lines in a frame
are scanned successively from top to bot-
tom. For interlace video, alternate lines are
scanned, and so a frame containing all the
picture information consists of two fields.
Frame Rate
The number of frames presented per sec-
ond. Note that for interlace systems the
frame rate is half the field presentation
rate.
Framestore
A device that captures, saves, and outputs
a still video image.
GSC
Global Serial Channel
High Definition Television (HDTV)
Television with a resolution approximately
twice that of Conventional Definition Tele-
vision in both the horizontal (H) and verti-
cal (V) dimensions and a picture aspect
ratio (H x V) of 16:9.
Interlace
A system of video scanning where the odd
and even numbered lines of a picture are
presented consecutively as two separate
interleaved fields. The two fields required
to make a complete picture are called a
frame.
Jitter
An undesirable variation in the timing of
transitions in a digital signal.
MPEG-2
A video compression mechanism em-
ployed by DTV to fit the digital data into
an existing 6 MHz bandwidth transmis-
sion channel.
Parallel Digital Video
(1) Passing multiple video data bits in par-
allel groups along a collection of wires
(called a bus). High Definition parallel dig-
ital video (1080i and 720p) typically uses
two parallel 10 bit buses (20 bits total) op-
erating at 74.25 MHz. In comparison, Stan-