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Expired Canadian patentCanada

Perceptual coding of audio-signals

CA 2117829 C · Owner: Sinha, Deepen · Inventors: Johnston, James David; Sinha, Deepen

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A five-channel perceptual audio compression system which encodes five matrixed channels switches among a fourteen encoding modes each utilizing a respective different set of matrixed channels. Six of the modes are for encoding the three front channels and eight of the modes are for encoding the two back channels. A number of the modes have as at least one of their respective matrixed channels a matrixed channel which is a function of a) one of the input channels or a sum ordifference of two of them and b) a predicted value of a).

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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 October 11, 1994 and granted June 30, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 11, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 11, 2016.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 11, 1994
GrantedJune 30, 1998
Term endedOctober 11, 2014
Patent numberCA 2117829 C
Classification (IPC)H04S3/02 +1 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedOct 11, 1994Patent grantedJune 30, 1998Term endedOct 11, 2014

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.