Facsimile and static presentation processing – Static presentation processing – Attribute control
Patent
1982-05-17
1984-10-23
Martin, John C.
Facsimile and static presentation processing
Static presentation processing
Attribute control
358 11, 358142, H04N 932, H04N 942, H04N 708
Patent
active
044791429
ABSTRACT:
Digitally encoded (DPCM) NTSC video is transmitted in a standard T3 data format and rate via a transmit interface module. The module is subjected to inputs comprising DPCM encoded NTSC video, horizontal sync and a video sampling clock at 3f.sub.sc, where f.sub.sc is the color subcarrier frequency. The sampling clock is used to write the DPCM encoded video and horizontal sync into a buffer. The buffer is read out via a read clock which is a submultiple of the 44736 MHz T3 rate. To assist in receiver decoding, the video data is supplemented with horizontal sync indicating code words, which designate the start of each horizontal scan line. On detection of a horizontal sync word read out of the buffer memory, the read clock is inhibited for the insertion of the horizontal sync indicating code words. The T3 frame is also supplemented with two digitized audio channels, stuff indicators and a stuff opportunity slot as well as parity, frame and multiframe indicators and an alarm channel. The T3 frame also carries data indicating a relationship between the T3 clock and f.sub.sc. This is useful at the receiver for ensuring that f.sub.sc at the receiver will track f.sub.sc at the transmitter. In accordance with standard T3 operation, the frame comprises 56 85-bit words, 28 odd and 28 even. The first bit of each 85-bit word is a control bit. Substantially all of the odd words include a 4-bit digitized audio nibble. Exceptions are two unused 4-bit nibbles, a single 4-bit stuff opportunity nibble and a single 4-bit video sample. Each of the even words includes 21 4-bit video samples which can be either video samples or sync indicating code words.
REFERENCES:
patent: 4122477 (1978-10-01), Gallo
Buschman Bob D.
Muth Glenn D.
O'Connell Ronald T.
M/A-COM DCC, Inc.
Martin John C.
Nguyen Luan
LandOfFree
Interface apparatus and method for asynchronous encoding of digi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Interface apparatus and method for asynchronous encoding of digi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interface apparatus and method for asynchronous encoding of digi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1601718