Switched filterbank for use in audio signal coding
CA 2199070 C · Owner: Johnston, James David · Inventors: Johnston, James David; Sinha, Deepen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An audio coding technique which utilizes a signal adaptive switched filterbank having a first filterbank and a wavelet filterbank. The filterbank switches between the first filterbank and the wavelet filterbank to filter an input signal as a function of the stationarity of the input signal. The first filterbank is utilized to filter stationary signal components. The wavelet filterbank is utilized to filter non-stationary signal components (e.g. attacks).
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 March 4, 1997 and granted May 15, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2019.
- 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.