7800 Multiframe Manual
7825DSK2-LG(-HD)(-3G) 3G/HD/SD Dual Downstream Keyer
Page 1-4
Revision 2.0
OVERVIEW
D1:
A component digital video recording format that uses data conforming to the ITU-R601
standard. Records on 19 mm magnetic tape. (Often used incorrectly to refer to component
digital video.)
D2:
A composite digital video recording format that uses data conforming to SMPTE 244M.
Records on 19 mm magnetic tape. (Often used incorrectly to refer to composite digital
video.)
D3:
A composite digital video recording format that uses data conforming to SMPTE 244M.
Records on 1/2" magnetic tape.
D5:
A component digital video recording format that uses data conforming to the ITU-R601
standard. Records on 1/2" magnetic tape.
Drop frame:
In NTSC systems, where the frame rate is 29.97002618 frames per second, the drop
frame mode permits time of day indexing of the frame numbers by dropping certain frame
numbers. Specifically frames 0, and 1 at the beginning of each minute except minutes
0,10,20,30,40, & 50, are omitted, to compensate for an approximate timing error of 108
frames (3 seconds 18 frames) per hour. A flag bit is set in the time code to signal when the
drop frame mode is in effect.
DVS/168:
A standard for carrying EAS notifications over TCP/IP. Crawl text (.txt) and sound (.wav)
files are copied via FTP, then activated by a notification over a custom TCP/IP port.
EAS:
Emergency Alert System, a national warning system employed in the U.S.
EBU (European Broadcasting Union):
An organisation of European broadcasters that among
other activities provides technical recommendations for the 625/50 line television systems.
Embedded audio:
Digital audio is multiplexed onto a serial digital video data stream.
ITU:
The United Nations regulatory body governing all forms of communications. ITU-R
(previously CCIR) regulates the radio frequency spectrum, while ITU-T (previously CCITT)
deals with the telecommunications standards.
ITU-R601:
An international standard for standard definition component digital television from which was
derived SMPTE 125M and EBU 3246-E standards. ITU-R601 defines the sampling
systems, matrix values and filter characteristics for Y, B-Y, R-Y and RGB component digital
television signals.
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
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