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Jam sync: Refers to the operation of slaving the generator to data coming from the reader. Jam sync
should be used when dubbing time code from one tape to another, as the quality of the time
code signal deteriorates with each generation, and will become unusable after the third
generation.
In the jam sync mode, the generator and reader times are compared with each other during
each frame, automatically compensating for the decoding offsets. If for any reason they are not
equal, the jam is bypassed, and the generator substitutes the next frame number. If the
number of consecutive jam bypass errors exceeds 5, the last valid reader time is jammed into
the generator again. In the absence of valid reader data within the last 5 frames, the generator
continues to increment normally until valid reader code resumes. At this time it will be re-
jammed to the reader, thus repairing large dropouts on the reader tape.
Letterbox: Placing a wide screen image on a conventional TV by placing black bands at the top and
bottom of the screen.
Linear time code:
(Also known as Longitudinal Time Code) A digital code used for timing and control
purposes on videotape and associated audio tape machines. It is recorded on a linear track
with audio characteristics and is referred to as LTC. Each 80 bit code word is associated with
one television frame, and consists of 26 time bits, 6 flag bits, 32 user bits and 16 sync bits. This
time code may run at 24, 25 or 30 frames per second depending on the video format. See also
SMPTE 12M
LTC:
See Linear Time Code
NTSC:
National Television Standards Committee established the television and video standard in use
in the United States, Canada, Japan and several other countries. NTSC video consists of 525
horizontal lines at a field rate of approximately 60 fields per second. (Two fields equals one
complete Frame). Only 487 of these lines are used for picture. The rest are used for sync or
extra information such as VITC and Closed Captioning.
PAL:
Phase Alternating Line. The television and video standard in use in most of Europe. Consists of
625 horizontal lines at a field rate of 50 fields per second. (Two fields equals one complete
Frame). Only 576 of these lines are used for picture. The rest are used for sync or extra
information such as VITC and Teletext.
Pixel:
The smallest distinguishable and resolvable area in a video image. A single point on the
screen.
In digital video, a single sample of the picture.
element.
Serial digital: Digital information that is transmitted in serial form. Often used informally to refer to serial
digital television signals.
SMPTE (Society of Motion Picture and Television Engineers): A
recommends standards for the film and television industries.
SMPTE 12M:
The SMPTE standard for Time and address code. SMPTE 12M defines the parameters
required for both linear and vertical interval time codes.
OVERVIEW
HD9010-SIE High Definition Source ID Encoder Manual
Revision 1.2
Derived from the words picture
professional
organisation
that
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