The Speex project
aims to build an open-source (LGPL) patent-free voice codec. Unlike
other codecs like MP3 and Ogg Vorbis, Speex is specially designed for compressing voice at low bit-rates
for applications such as voice over IP (VoIP). In some sense, it is meant
to be complementary to the Ogg Vorbis codec.
If you are interested in participating to the project, contact us at
speex-devel@lists.sourceforge.net or
join our mailing list. Right now, we are mostly looking for
developers with signal processing and speech coding knowledge, as well
as people with knowledge about patents in that field.
Download
You can download Speex from
here.
Documentation
Speex Programming Guide
Speex API (generated by Doc++)
News
2002/05/15
Speex 0.1.0 has been released. Speex now uses the Ogg bitstream (using libogg). That means that
there is now (limited) bitstream error recovery. Also, the narrowband bit-rate has been reduced
from 15.7 kbps to 15.1 kbps and the wideband bit-rate has been reduced from 31.3 kbps to 27.7 kbps.
The quality remains roughly the same for both narrowband and wideband.
Once again, this breaks compatibility with previous versions.
2002/05/07
Speex 0.0.3 released.
2002/04/15
Speex version 0.0.2 has been released. This release provides much improved
wideband quality at an only slightly higher bit-rate of 31.3 kbps. This
means that the wideband Speex files are not compatible with those of the 0.0.1
release. The narrowband codec (at 14.5 kbps) is however exactly the same
as in 0.0.1.
2002/03/27
Speex 0.0.1 has been released. This first version of Speex supports
fixed bit-rate encoding at 14.5 kbps for speech sampled at 8 kHz (narrowband)
and at 28.5 kbps for 16 kHz (wideband) speech. Future releases will likely
provide a wider choice of bit-rates, better quality, as well as variable
bit-rate (VBR) and discontinuous transmission (DTX).
Note that this is a preliminary release and that bit-rates, quality
and bitstream definition will change in the future. This means that
the format used in this release will not be compatible with future releases.
Also note that this software has so far received only a minimum amount
of testing, so it may break or do unexpected things.
2002/03/12
We now have a working encoder prototype that produces good quality
narrowband (8 kHz sampling rate) at a bit-rate of 14.5 kb/s. There is
still a lot to do, but we're progressing fast.