Jean-Marc Valin
2006-Dec-05 15:00 UTC
[Speex-dev] get the mode from a incoming speex stream
In a "normal" frame that doesn't have in-band signalling (which nobody seems to use anyway), the frame starts with the narrowband information. If the frame is in wideband, then this will be followed by a bit of wideband information that starts with a bit set to 1 (narrowband starts with a bit set to 0). Have a look at what the Speex decoder does. You may actually want to have similar code in a "null decoder". Jean-Marc Aymeric Moizard a ?crit :> > Hi speexers, > > I want to be able to automatically detect the mode (narrowband/wb..) > of the RTP stream I'm receiving. > > I guess this information is included in frames? Isn'it? > How can I read it? > > tks, > Aymeric MOIZARD / ANTISIP > amsip - http://www.antisip.com > osip2 - http://www.osip.org > eXosip2 - http://savannah.nongnu.org/projects/exosip/ > > _______________________________________________ > Speex-dev mailing list > Speex-dev@xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev > >
Hi Jean-Marc, I remember you said that the SDP tells the mode information. Is SDP what you called in-band signalling? Lianghu On 12/6/06, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> wrote:> > In a "normal" frame that doesn't have in-band signalling (which nobody > seems to use anyway), the frame starts with the narrowband information. > If the frame is in wideband, then this will be followed by a bit of > wideband information that starts with a bit set to 1 (narrowband starts > with a bit set to 0). Have a look at what the Speex decoder does. You > may actually want to have similar code in a "null decoder". > > Jean-Marc > > Aymeric Moizard a ?crit : > > > > Hi speexers, > > > > I want to be able to automatically detect the mode (narrowband/wb..) > > of the RTP stream I'm receiving. > > > > I guess this information is included in frames? Isn'it? > > How can I read it? > > > > tks, > > Aymeric MOIZARD / ANTISIP > > amsip - http://www.antisip.com > > osip2 - http://www.osip.org > > eXosip2 - http://savannah.nongnu.org/projects/exosip/ > > > > _______________________________________________ > > Speex-dev mailing list > > Speex-dev@xiph.org > > http://lists.xiph.org/mailman/listinfo/speex-dev > > > > > _______________________________________________ > 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/20061206/e3e7b679/attachment.html
Aymeric Moizard
2006-Dec-06 03:22 UTC
[Speex-dev] get the mode from a incoming speex stream
On Wed, 6 Dec 2006, lianghu xu wrote:> Hi Jean-Marc, > > I remember you said that the SDP tells the mode information.Right. But a decoder like speex can always be configured from information contained in the incoming stream. That makes your application more interroperable. Aymeric MOIZARD / ANTISIP amsip - http://www.antisip.com osip2 - http://www.osip.org eXosip2 - http://savannah.nongnu.org/projects/exosip/> Is SDP what you called in-band signalling?> Lianghu > > On 12/6/06, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> wrote: >> >> In a "normal" frame that doesn't have in-band signalling (which nobody >> seems to use anyway), the frame starts with the narrowband information. >> If the frame is in wideband, then this will be followed by a bit of >> wideband information that starts with a bit set to 1 (narrowband starts >> with a bit set to 0). Have a look at what the Speex decoder does. You >> may actually want to have similar code in a "null decoder". >> >> Jean-Marc >> >> Aymeric Moizard a ?crit : >> > >> > Hi speexers, >> > >> > I want to be able to automatically detect the mode (narrowband/wb..) >> > of the RTP stream I'm receiving. >> > >> > I guess this information is included in frames? Isn'it? >> > How can I read it? >> > >> > tks, >> > Aymeric MOIZARD / ANTISIP >> > amsip - http://www.antisip.com >> > osip2 - http://www.osip.org >> > eXosip2 - http://savannah.nongnu.org/projects/exosip/ >> > >> > _______________________________________________ >> > Speex-dev mailing list >> > Speex-dev@xiph.org >> > http://lists.xiph.org/mailman/listinfo/speex-dev >> > >> > >> _______________________________________________ >> Speex-dev mailing list >> Speex-dev@xiph.org >> http://lists.xiph.org/mailman/listinfo/speex-dev >> >