Subject: [AVT] Speex: open-source, IPR-free speech codec

From: Jean-Marc Valin <[email-masked]>
Date: 18 Jun 2002 00:43:02 -0400

Hi,

I've seen some discussion about the iLBC codec on this list and would
like to draw attention to another effort to provide an IPR-free speech
codec. The Speex project (http://speex.sourceforge.net/) has roughly the
same goal: free speech coding adapted to VoIP applications. (Note: I am
the main developer of Speex, so you may consider me biased)

Speex provides both narrowband (8 kHz sampling) and wideband (16 kHz
sampling rate) encoding. Right now, the narrowband bit-rates available
are 7.9 kbps and 14.8 kbps, while the wideband bit-rates are 20.2 kbps
and 27.4 kbps. To my ear the 14.8 kbps mode of Speex sounds
significantly superior to the 14 kbps mode available in iLBC (of course,
this is not a scientific evaluation!). As is the case of iLBC, Speex is
designed to be relatively robust to packet loss, but not to
bit-corruption (like for cell-phone codecs).

Speex is still in development, but it is already quite usable and is
capable of coding tones and music without too much degradation. The only
major feature that is still missing at this point is variable bit-rate
(VBR). 

	Jean-Marc

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