|
Hi all, Do anyone know of a way to detect DTMF on a GSM AMR bitstream without fully decoding it? I will be happy to know if you can do it on ITU-T voice codecs as well (G.723.1, G.728, G.729). Thanks |
|
|
DTMF detection on a GSM AMR bitstream
Started by ●June 29, 2003
Reply by ●June 29, 20032003-06-29
|
On Sun, Jun 29, 2003 at 07:19:02AM -0000, e_voice61 wrote: > Hi all, > > Do anyone know of a way to detect DTMF on a GSM AMR bitstream without > fully decoding it? > I will be happy to know if you can do it on ITU-T voice codecs as > well (G.723.1, G.728, G.729). > These codecs are optimized for voice. They are not able to carry DTMF tones reliably. So even with a full decode, you won't be able to detect them. They have to be transmitted out-of-band. -- Nicolas Bougues Axialys Interactive |
Reply by ●July 1, 20032003-07-01
|
G.728 will pass DTMF tones with perfect results as theory predicts and both
lab and field testing have validated. The same is true for at least Annex E of G.729. And as you said, G.723.1 will unfortunately not pass DTMF at either rate. Chuck In a message dated 6/29/2003 2:52:06 PM Eastern Standard Time, writes: > > > On Sun, Jun 29, 2003 at 07:19:02AM -0000, e_voice61 wrote: > > Hi all, > > > > Do anyone know of a way to detect DTMF on a GSM AMR bitstream without > > fully decoding it? > > I will be happy to know if you can do it on ITU-T voice codecs as > > well (G.723.1, G.728, G.729). > > > > These codecs are optimized for voice. They are not able to carry DTMF > tones reliably. So even with a full decode, you won't be able to > detect them. > > They have to be transmitted out-of-band. > -- > Nicolas Bougues > Axialys Interactive > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: > > To Post: > > To Leave: > > Archives: http://www.yahoogroups.com/group/speechcoding > > Other DSP-Related Groups: http://www.dsprelated.com > ">http://docs.yahoo.com/info/terms/ |
