Table of Contents
Advertisement
Glossary
Reference video
signal
A video signal which
contains a sync signal or
sync and burst signals,
used as a reference for
synchronization of video
equipment.
R-Y signal
One of the color
difference signals, the R
(red) signal minus Y
(luminance) signal.
Sampling frequency
The unit of time used
when converting an
analog signal with a
continuously varying
level to digital form by
sampling the level at a
fixed interval. In general,
a higher sampling
frequency makes it
possible to digitize
analog signals of a
higher frequency.
A-24
Appendixes
SCH
Abbreviation of Sub
Carrier to Horizontal.
The phase of the
subcarrier with respect
to the phase of the
horizontal
synchronization signal.
In editing of
monochrome video,
phase continuity is
maintained by editing in
units of frames (two
fields), so that the
continuity of the
horizontal
synchronization signal
phase is maintained.
Editing of color video
must be done in units of
two frames (four fields)
to maintain subcarrier
continuity. The SCH of a
field can be checked to
find out which of the
four fields it represents.
This allows edited video
signals to be joined
while maintaining
subcarrier continuity.
Search
Viewing the picture or
timecode by running the
tape in fast forward or
rewind mode, in order to
search for a particular
scene.
Servo
A mechanism that
controls the number and
phase of rotations of the
head drum or capstan.
Servo mechanism allows
playback of the video
signal without guard
band noise. The
reference signal of the
servo control is normally
a vertical sync signal.
Servo lock
This refers to the
synchronization of the
phase of the drum
rotation and the
reference signal for the
tape transport position,
so that the video heads
can trace the same
pattern on the tape for
playback and recording.
SMPTE
Abbreviation of Society
of Motion Picture and
Television Engineers, a
professional association
established in the USA.
S/N
Signal-to-Noise ratio.
The relation of the
strength of the desired
signal to the
accompanying electronic
interference, the noise.
If S/N is high, sounds
are reproduced with less
noise and pictures are
reproduced clearly
without snow.
Advertisement
Table of Contents
