Re: How to detect tone signals by our modem?

moham14@[EMAIL PROTECTED]
 wrote:
> Does anyone know how we can detect the numbers which the dialer person
> presses on his telephone by our modem?
> 
> I have downloaded some TAPI commands. With these commands in a simple
> Delphi program I can wait for a outside dial and then pick up the hand
> set when there is a ringing, by modem. But what I realy need is that
> what should I do to detect the numbers that the dialer person presses
> on his telephone after my modem picks up the handset(virtually of
> course).
> 
> This is needed when the programs shoud receive an access code or an
> account number.
> 
> In addition to tone detection, if you help me to know the way that we
> can play a WAV file(or any kind that is possible) to the dialer person
> for guiding hom by some voice messages it will be very well.
> Thanks for your help
> 
> 
> 
> 
> 
> 
> 
> 
> 4461510_1
> 
you need an internal voice/fax type modem which you most likely have.
then you need to learn a little about wave recording using the MMSYSTEM 
code. its quite extensive so i would suggest finding some examples on
simple audio recording from the sound card.
    many voice modems will appear as a Wave device with a rough quality 
of recording, you simply need to config the recording and use DFT
  (Discrete fourier transforms) FFT is what you need to look for on the
net for example code of converting PCM bits into table of Coefficients 
that represent amp levels of tones.
  you need to detect the dual octive tones that come from the push
buttons.