Patent Yard Sign in
Expired Canadian patentCanada

Improved audio coding systems and methods using spectral component coupling and spectral component regeneration

CA 2521601 C · Owner: Williams, Philip Anthony · Inventors: Vernon, Stephen Decker; Williams, Philip Anthony; Andersen, Robert Loring

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

An audio encoder discards spectral components of an input signal and uses channel coupling to reduce the information capacity requirements of an encoded signal. Channel coupling represents selected spectral components of multiple channels of signals in a composite form. An audio decoder synthesizes spectral components to replace the discarded spectral components and generates spectral components for individual channel signals from the coupled-channel signal. The encoder provides scale factors in the encoded signal that improve the efficiency of the decoder to generate output signals that substantially preserve the spectral energy of the original input signals.

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 April 30, 2004 and granted August 20, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 30, 2024.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 30, 2026.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 30, 2004
GrantedAugust 20, 2013
Term endedApril 30, 2024
Patent numberCA 2521601 C
Classification (IPC)G10L19/00 +2 more

Timeline

Timeline From CIPO dates

2005200720092011201320152017201920212023Application filedApril 30, 2004Patent grantedAug 20, 2013Term endedApril 30, 2024

Sources & verification

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