Celp-based speech compressor
CA 2096991 C · Owner: He Holdings, Inc. · Inventors: Swaminathan, Kumar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high quality low bit rate audio codec having a reproduced voice quality that is comparable to that of a full rate codec compresses audio data sampled at8 Khz e.g. 64 Kbps PCM to 4.2 Kbps or decompresses it back to the original audio or both. The accompanying degradation in voice quality is comparable to the standard 8.0 Kbps voice codes. This is accomplished by using the same parametric model used in traditional CELP coders but determining quantizing encoding and updating these parameters differently. The low bit rate audio decoder is like most CELP decoders except that it operates in two modes depending on the received mode bit. Both pitch prefiltering and global postfiltering are …
Read the whole patent
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 May 26, 1993 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 26, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 26, 2015.
- 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.