Wolfgang Fritz wrote:
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>
> There exists a long text about DTMF detection somewhere on the net (I
> may have the link in the office but I'm on vacation now). What I
> remember is that a "correct" DTMF detection requires much more computing
> power as the present i4l implementation needs (much longer audio samples
> for the goertzel filter, a larger number of frequencies to check) and a
> standard test procedure with a lot of test cases which are not available
> to mortal humans (audio tapes from Bellcore IIRC)
>
The link below is not the text I mean above but shows an approach which
is similar to the present i4l implementation but has some improvements
which may be good enough for us.
http://www.mitsubishichips.com/press/dtmf0199e.pdf
> Wolfgang
> >
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