[asterisk-dev] DTMF detection in dsp.c intolerant?

Eric "ManxPower" Wieling eric at fnords.org
Wed Aug 22 10:59:21 CDT 2007

Maybe so, but it has fixed DTMF issues for me in the past.

Steve Underwood wrote:
> Eric "ManxPower" Wieling wrote:
>> Try increasing or decreasing your zaptel rxgain by a couple of Db down 
>> or up.
> Change the gain - the favourite resort of the desperate. :-)
> This audio is only 6dB below clipping right now.
>> Tony Mountifield wrote:
>>> In article <46CC389F.4040707 at coppice.org>,
>>> Steve Underwood <steveu at coppice.org> wrote:
>>>> Those files decode OK with the DTMF decoder in spandsp. Since the one in 
>>>> * is based on that, the problem must be due to something subtle in the 
>>>> differences.
>>> Hi Steve, many thanks for your reply. Would you mind running the following
>>> file through the same decoder?
>>> http://www.softins.co.uk/dtmf-call-31378.wav
>>> In this one the audio is not so clean, but I would have thought a good
>>> decoder should still be able to extract the DTMF.
>>> The string sent was again *82779736*91856360** but this time Asterisk
>>> only detected *87936*918636*
>>> I'll have a look at the decoder in spandsp and try to compare it with
>>> the one in Asterisk.
>>> BTW, I'm using Asterisk 1.2.
>>> Cheers
>>> Tony
> I actually looked at the audio. Its seriously screwed up. Every digit 
> has two short beeps before it. Its consistent on every digit.

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