Hi, mod_vmd is a bit more sophisticated than that. It looks for the signal being narrowband energy. However, mod_vmd isn't very reliable, as it takes a rather high SNR for its narrowband detector to work. So high that a lossy codec like G.711 can barely manage it.
Regards, Steve Anthony Minessale wrote: > i think that's what mod_vmd does > > On Mon, Mar 2, 2009 at 11:16 AM, Andy Spitzer <w...@nortel.com > <mailto:w...@nortel.com>> wrote: > > Woof! > > On Sun, 01 Mar 2009 21:28:18 -0500, Brian West > <br...@freeswitch.org <mailto:br...@freeswitch.org>> wrote: > > > NO. You want something that people THINK exists and works well... > > Reliable human/voice detection doesn't exist in ANY form. > > I beg to differ. See > http://www.freepatentsonline.com/5521967.html for one way to do > it. It works rather well and can quickly descriminate between > voice and tone. I've no idea who owns that patent now (not me, > for sure). > > There is a simpler, less reliable way of differentiating voice > from tone, that as far as I know isn't patented. If you compare > the RMS power levels of sequential 40 mS periods, call progress > tones will have very consistent power levels from sample to > sample. So if 5 or more 40 mS periods have about the same power > measurement (within say, 2%), it's a tone. Voice will have > dramatic power level differences over that same period. This > works very well in today's telephony environment, where tones are > computer generated. In the old days when ringback tone was > generated off the audio hum from the 20 Hz ring voltage > generator...not so well. > > --Woof! > > _______________________________________________ > Freeswitch-users mailing list > Freeswitch-users@lists.freeswitch.org > <mailto:Freeswitch-users@lists.freeswitch.org> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users > http://www.freeswitch.org > _______________________________________________ Freeswitch-users mailing list Freeswitch-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
