[EMAIL PROTECTED] wrote: > From: "maverick me" <[EMAIL PROTECTED]> > > Is there any open source available that support detection of In-Band DTMF. > > The sipX system's voicemail system uses RFC 4733 DTMF. I don't know > if you consider that to be in-band. If you want to detect and decode > DTMF out of a real audio stream, that's a difficult task -- many of > the more efficient codecs damage DTMF tones enough that it's difficult > to recognize them reliably.
Indeed. You can't straightforwardly apply acoustic DTMF detection algorithms built on the assumption of a clear-channel 8000 Hz PCM frame stream to something pulverised by G.729A. But the most important question, I think, was asked by someone earlier in the thread - why? Who cares? What are you trying to accomplish? Perhaps there is a better way. -- Alex Balashov Evariste Systems Web : http://www.evaristesys.com/ Tel : (+1) (678) 954-0670 Direct : (+1) (678) 954-0671 Mobile : (+1) (706) 338-8599 _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
