Florian Lefeuvre wrote:

Hi Steve,

I was the one who post a question about the RADIO_RELAX option.
In fact when I set it , I remark some better result in the detection of the DTMF...
after a few more tests, It appears I was wrong.
I did a record of samples used by the DTMF_detect function.
I obtain an audio file : PCM , 16 bits signed, big endian, Fs 8kHz.
If I compare an audio file of DTMF generated by land line with one generated
by GSM phone, I remarks a big difference.
for a land line, the shape is very good., amplitude is nearly constant for a dtmf.
for a gsm phone, the shape is bad, it can can an amplitude 5 times bigger than a land line.
After some tests, I see that lot's of errors occurs when the signal amplitude was too big (saturation).
I wonder if I should clip or attenuate the signal or a better detection...
if you want I can send you some file....



Florian

Send me some data, and I will tak a look. If the signal has overloaded it will not detect, as there will be too much harmonic energy to pass the tests.


Regards,
Steve

_______________________________________________
Asterisk-Users mailing list
[email protected]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users

Reply via email to