Perceptual noise shaping in the time domain via lpc prediction in the frequency domain
CA 2194419 C · Owner: At&T Corp. · Inventors: Herre, Juergen Heinrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for the perceptual coding of audio signals in which perceptual noise shaping is achieved in the time domain by performing a (linear) prediction (i.e. filtering) in the frequency domain. As a result the temporal spread of quantization, noise is reduced. Specifically according to one illustrative embodiment of the present invention, a method comprises decomposition of the audio signal into a plurality of spectral component signals; generating a prediction signal representative of a prediction of one of said spectral component signals, said prediction based on one or more other ones of said spectral component signals; comparing the prediction signal with said one of said …
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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 January 6, 1997 and granted May 1, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 6, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 6, 2019.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.