Matt, As is mod_vmd will not detect tones shorter then 138ms. However I could get that value down to ~30ms at best by making a few modifications to the algorithm.
Cheers. Eric des Courtis On Thu, Aug 20, 2009 at 7:51 PM, Eric des Courtis<[email protected]> wrote: > Matt, > > For your information the tones you gave me are exactly 738Hz. If you > want to try that tone detection thing. > > Cheers. > > Eric des Courtis > > On Thu, Aug 20, 2009 at 2:20 PM, Michael Collins<[email protected]> wrote: >> >> >> On Thu, Aug 20, 2009 at 11:06 AM, Steve Underwood <[email protected]> >> wrote: >>> >>> On 08/20/2009 05:22 AM, Michael Collins wrote: >>> > >>> > There is no noise on those 3 beeps. In fact, for something that's >>> > been >>> > through ulaw/alaw compression those beeps are very clean. They are >>> > quite >>> > short, though. >>> > >>> > >>> > Heck yeah they're short! Steve, in your experience is there a >>> > practical way to detect a beep that short without chewing up system >>> > resources or having lots of false positives? >>> > -MC >>> > >>> The tone samples I just looked at are about 130ms long. The problem is >>> the detector is trying to be a very open ended detector of anything >>> narrowband enough to be a single tone, and of any duration beyond some >>> small minimum. Its difficult to make such a thing voice immune unless >>> you can also count on a very large signal to noise ratio. With a digital >>> trunk you can probably rely on a large SNR, but what happens when people >>> use analogue lines? There is a reason why DTMF detectors try hard to >>> work down to about 10dB SNR. :-) >>> >>> Steve >> >> Thanks for the lesson uncle Steve! I'm guessing that the OP will need a new >> strategy. Possibly waiting for silence? Not sure what's the best way to go >> but I'm interested in hearing if someone has a solution. >> >> -MC >> >> >> >> _______________________________________________ >> FreeSWITCH-users mailing list >> [email protected] >> 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 [email protected] http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
