March 28, 2002

Speex: open-source, patent-free voice compression

Jean-Marc Valin writes "We would like to announce the first release of the Speex project. Speex is an open-source (LGPL), patent-free compression format allowing an alternative to expensive proprietary codecs. Unlike Ogg Vorbis which compresses general audio, Speex is designed especially for speech. For that reason, Speex is meant to be a complement to Vorbis. Since it is specialized for voice communications, it is possible to attain lower (compared to Ogg Vorbis/MP3) bit-rates in the 8-32 kbps/channel range. Possible applications include Voice over IP (VoIP) applications, Internet audio streaming at low bit-rate and archiving of speech data (e.g. voice mail).

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)."


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