Method and apparatus for inverse quantization of mpeg-4 video
CA 2329725 A1 · Owner: General Instrument Corporation · Inventors: Chen, Xuemin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Inverse quantization (36, 44, 60) of a two-dimensional array of video coefficients QFvu is provided. A first weighting matrix <o>W</o>0vu=2*W0vu for intra-coded macroblocks and a second weighting matrix <o>W</o>1vu=2*W1vu for non-intra-coded macroblocks are pre-computed and stored (88). A quantization difference (quanti+1) to be used in selecting a weight factor is computed (70) based on a current macroblock quantization level. The weight factor is output from one of the weighting matrices in response to the quantization difference and a macroblock type identifier (66) (i.e. intra-coded or non-intra-coded). Subsequent weights Wi+1wvu are then computed (86) from a current weight …
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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
- Filed April 27, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 27, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 27, 2021.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.