Hi, I've been testing out the speex narrowband codec at low data rates (using linphone and Counterpath's Eyebeam). I'm finding that at data rates of ~25 kbps, the quality of the voice call is very poor. I know speex is supposed to work at much lower data rates (~2 kbps). Has anyone verified that speex will produce reasonable quality at low data rates? Are there any existing VoIP software clients that will utilize speex at low data rates? Any help is greatly appreciated! Thanks! Julee -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20090424/29cc74ce/attachment.htm
Pandya, Julee a ?crit :> I?ve been testing out the speex narrowband codec at low data rates > (using linphone and Counterpath?s Eyebeam). I?m finding that at data > rates of ~25 kbps, the quality of the voice call is very poor.If the sound quality is poor at those rates, then it's a bug somewhere (interoperability problem, losing packets, ...)? I know> speex is supposed to work at much lower data rates (~2 kbps). Has > anyone verified that speex will produce reasonable quality at low data > rates? Are there any existing VoIP software clients that will utilize > speex at low data rates?There's no point in using 2 kbps for VoIP because just sending 20 ms costs you 16 kbps in headers (IP/UDP/RTP) alone. Jean-Marc
SipXtapi, and I believe many other SIP UAs use sip at much lower bitrate than you are -- 8kHz vs 25kHz. Quality is very good at 8khz - speech quality that is. If you're trying to use speex to compress music, forget it as speex was not designed for that -- use vorbis instead. On Apr 24, 2009, at 14:09, "Pandya, Julee" <julee.pandya at lmco.com> wrote:> Hi, > > > > I?ve been testing out the speex narrowband codec at low data rates ( > using linphone and Counterpath?s Eyebeam). I?m finding that at > data rates of ~25 kbps, the quality of the voice call is very poor. > I know speex is supposed to work at much lower data rates (~2 kbps) > . Has anyone verified that speex will produce reasonable quality at > low data rates? Are there any existing VoIP software clients that > will utilize speex at low data rates? > > > > Any help is greatly appreciated! > > > > Thanks! > > Julee > > _______________________________________________ > Speex-dev mailing list > Speex-dev at xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20090515/995d85fe/attachment.htm