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

Steve Underwood steveu at coppice.org
Wed Aug 22 10:20:04 CDT 2007

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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