--------------- (Re-sent; I don't think it got through for some reason.) Hi, folks.
This note is more so it can be archived and indexed for future Google-ing. But maybe it'll help somebody already on the list. I had trouble with a link to my 6M ham repeater's autopatch facility. When I plugged a plain old VoIP telephone adaptor onto the repeater, all was well. Same with a POTS line from the phone company. But when hooked to a Wildcard, DTMF decode was poor to non-existent. I asked here, and never got any response on the issue. But you gotta love open source. I spent a little effort on it on and off when time permitted, and found that although the Wildcard has a DSP with DTMF decode, it's not used; the DTMF processing is soft, up in the Asterisk process. That's actually good news, because I added instrumentation to the decode process, dumping it to a trace file in /tmp. Then I had a little dump program which would format this after the fact, letting me see what was happening during the (attempted) decode. Bottom line from the trace was that, for the kinds of signal levels coming from my autopatch, DTMF_TO_TOTAL_ENERGY was quite a bit too high. I empirically determined that the default value of 42.0 should be tweaked down to perhaps as low as 35.0. There was already a compile option RADIO_RELAX, and a "relaxdtmf" option in the zapata.conf file. These didn't fix the problem for me, but they provided a nice hook for me to add my own fix. I added a conditional modification of the DTMF_TO_TOTAL_ENERGY value under the same "relaxdtmf" option, and bingo! DTMF seems to be working fine. I'll live with it for a while, see if I have problems with false decodes or what-not. Maybe I'll bring the value up a little, because there are a couple layers to the logic in DTMF decoding to defend against scratchy DTMF input anyway. Then I guess I'll submit it for consideration in the Asterisk source. Regards, Andy Valencia _______________________________________________ Asterisk-BSD mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-bsd
