[vorbis-dev] Speex: Open-source, patent-free speech coding

[Jean-Marc Valin]

Le jeu 28/03/2002 à 13:16, Kendal a écrit :
> To the best of my knowledge, CELP is a patented method that requires licensing.
> See: http://www.voiceage.com
> 
> How can you produce a CELP codec that circumvents existing patents?

They own a patent on ACELP (Algebraic CELP), invented at the University
of Sherbrooke (I did my master with them and VoiceAge). CELP was
invented by Atal in the early 80's and is not patented AFAIK. ACELP is
now the most widely used technique, but unfortunately, we cannot use it
because of patents. We're using a "multi-pulse-like" method, but without
the search efficiency of ACELP. If you know about patents on multi-pulse
or other topics in Speech coding, please let me know.

        Jean-Marc


-- 
Jean-Marc Valin, M.Sc.A.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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