104
Glossary
A
ppe
ndix
video and digital television
transmission, it maintains high image
quality while achieving high
compression ratios, using predictive
techniques for capturing motion.
Non-drop frame mode
A mode of advancing timecode
which ignores the difference in frame
values between real time and the
timecode. Using this mode produces
a difference of approximately 86
seconds per day between real time
and timecode, which causes
problems when editing programs in
units of seconds using the number of
frames as a reference.
Non-linear editing
Editing while playing back video and
audio signals recorded on hard disks.
Video scenes stored on disk can be
cued up quickly, for increased editing
efficiency. See also “Linear editing.”
PCM audio
This is an audio signal represented by
pulse code modulation. The analog
audio signal is first broken down into
a sequence of pulses, and these are
then represented digitally.
Preroll
Running of a video tape to a prior to
an edit-start point to enable the tape
to reach a steady speed and to be
synchronized with other video tapes.
R-Y signal
A chrominance signal determined by
subtracting the Y (luminance) signal
from the R (red) signal. One of the
component signals.
Reference video signal
A video signal consisting of a sync
signal or sync and burst signals, used
as a reference.
RP188
Specifications by the American
Society of Motion Picture and
Television Engineers (SMPTE) for
transmitting control codes and
timecode in the ancillary data space
of digital television signals
SDSDI signal
SD Serial Digital Interface. An
interface standardized as SMPTE
259M which enables the
transmission of an uncompressed
digital component stream.
Setup (59.94i)
The difference between the reference
black level and the blanking level of
a composite signal.
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.
Search mode
A VCR operating mode used when
searching for specific scenes, by
viewing the video output or timecode
values while playing back the tape at
various speeds in forward or reverse
direction.
Servo lock
Synchronizing the drum rotation
phase and tape transport phase with a
reference signal during playback and
recording so that the video heads scan
the tape in the same pattern during
playback and recording.
Standby Off mode
One of two conditions in the stop
mode. The drum does not rotate and
tape is slackened. There is no damage
to the video heads and the tape, but
the VCR is not ready for immediate
recording or playback.
Standby on mode
One of two conditions in the stop
mode. The drum is rotating and the
tape is wrapped round the drum. The
VCR is ready for recording or
playback, so a still picture can be
obtained.
Subcarrier
A sine wave imposed on the
luminance portion of a video signal
and modulated to carry color
information. Its amplitude represents
color saturation and its phase
represents hue.
Superimpose
To put a set of characters onto a
picture so that both can be seen at the
same time.
Squeeze
Method of down-converting a 16:9
HD signal to 4:3 video by
compressing the image horizontally.
S-video
A signal format in which Y
(luminance) and C (chrominance)
signals are separated to reduce
interference between them so that
noiseless images are reproduced.
Sync signal
A reference signal consisting of
vertical and horizontal sync signals
used for synchronizing the scanning
patterns of the video camera and the
monitor.
TBC
Abbreviation of Time Base
Corrector. Electronic circuits to
electrically stabilize the playback
signals by removing color variation
and roll in the playback picture
caused by irregularity in drum
rotation and tape movement. Time
