Two-channel coding of digital signals
CA 1261069 A · Owner: Nortel Networks Corporation · Inventors: Prasada, Birendra; Sabri, Mohamed S.; Golembiowski, Albert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of Disclosure A video codec is used to reduce the bandwidth of a video signal for storage and/or transmission. To transmit an uncoded quality colour NTSC television signal in digitized form requires channel bandwidth typically 90-120 Mb/s for the signal in the composite format and 216 Mb/s for the signal in the component format. The proposed video codec achieves a reduction of the required transmission bandwidth by a factor of 2-3 by splitting the input signal into two channels, a main and a complementary channel and by, applying different coding techniques in each. In the main channel the input signal is subsampled and DPCM encoded using a fixed-rate companded quantization, …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.