Hi all, Has anyone tried conveying signaling tones (DTMF) through speex? If so, can i get an idea of the lowest bit-rate at which I can do so with 'tolerable distortion'. G.728 does so and G.729E (11.8 Kbps mode) is 'claimed' to do so but even if true, G.729 (rather G.729I - 11.8/8/6.4 kbps) does not allow me to go below 6.4 kbps if needed. Basically I am looking for a single codec which would allow me to play with multiple (low) bit-rates within voice and switch to a higher bit-rate upon detecting a signaling tone instead of using RFC 2833/out-of-band signaling methods. I hope speex is the solution am looking for! Regards, Mainak PS: In any case I will have to test it out myself but a positive answer to this query would definelty brighten up the road ahead :-) -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20070504/4dc07473/attachment-0001.htm
Hi Mainak, Speex will definitely be able to handle DTMF. The only question is what the minimum rate for that will be. I remember testing on a few tones at 8 kbps and I didn't hear too much distortion (though there have have been). The only thing I can recommend is to use a higher complexity setting that one would normally use. For voice, I can't really tell the difference between quality 1 and quality 3, but for DTMF, it actually makes a big difference. I'd recommend using complexity 3 or 4 if you can afford it (in speexenc, you can change that with --comp and the default is 3). Jean-Marc Mainak Chakraborty a ?crit :> Hi all, > Has anyone tried conveying signaling tones (DTMF) through speex? If so, can > i get an idea of the lowest bit-rate at which I can do so with 'tolerable > distortion'. G.728 does so and G.729E (11.8 Kbps mode) is 'claimed' to > do so > but even if true, G.729 (rather G.729I - 11.8/8/6.4 kbps) does not allow me > to go below 6.4 kbps if needed. Basically I am looking for a single codec > which would allow me to play with multiple (low) bit-rates within voice and > switch to a higher bit-rate upon detecting a signaling tone instead of > using > RFC 2833/out-of-band signaling methods. I hope speex is the solution am > looking for! > Regards, > Mainak > > PS: In any case I will have to test it out myself but a positive answer to > this query would definelty brighten up the road ahead :-) > > > ------------------------------------------------------------------------ > > _______________________________________________ > Speex-dev mailing list > Speex-dev@xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev
Hi Jean, Thats great news for me to start off with as I was planning to go with 16 Kbps ADPCM keeping in mind the issues and options I had. Now, whether the additional computation cost is worth the significant bandwidth savings, I have to see. Just wondering if it is possible to extend this logic to G3 and G4 fax as well, i.e. using a higher bit-rate and complexity mode for modem or fax instead of going for a higher bit-rate ADPCM. If so, a one stop solution for all kinds of traffic would be awesome. Thanks a lot for the prompt reply, Mainak On 5/4/07, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> wrote:> > Hi Mainak, > > Speex will definitely be able to handle DTMF. The only question is what > the minimum rate for that will be. I remember testing on a few tones at > 8 kbps and I didn't hear too much distortion (though there have have > been). The only thing I can recommend is to use a higher complexity > setting that one would normally use. For voice, I can't really tell the > difference between quality 1 and quality 3, but for DTMF, it actually > makes a big difference. I'd recommend using complexity 3 or 4 if you can > afford it (in speexenc, you can change that with --comp and the default > is 3). > > Jean-Marc > > Mainak Chakraborty a ?crit : > > Hi all, > > Has anyone tried conveying signaling tones (DTMF) through speex? If so, > can > > i get an idea of the lowest bit-rate at which I can do so with > 'tolerable > > distortion'. G.728 does so and G.729E (11.8 Kbps mode) is 'claimed' to > > do so > > but even if true, G.729 (rather G.729I - 11.8/8/6.4 kbps) does not allow > me > > to go below 6.4 kbps if needed. Basically I am looking for a single > codec > > which would allow me to play with multiple (low) bit-rates within voice > and > > switch to a higher bit-rate upon detecting a signaling tone instead of > > using > > RFC 2833/out-of-band signaling methods. I hope speex is the solution am > > looking for! > > Regards, > > Mainak > > > > PS: In any case I will have to test it out myself but a positive answer > to > > this query would definelty brighten up the road ahead :-) > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Speex-dev mailing list > > Speex-dev@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/20070507/5d24cf7e/attachment.htm