How to detect DTMF digits during active call

[rakesh1809]

Hi,

I am developing one Mobile Client/Dialer application (For Enterprise features like Fixed Mobile Convergence and Mobile-Extensions) which is used to make call using Cellular Network.

When User wants to activate Call Forward features. For this, User selects Call Forward from Mobile Dialer's option menu and activate it. Mobile Dialer application makes call to one predefined number (say Enterprise's Pilot number) and when enterprise system answers the call, Mobile dialer application dials Call Forward access codes using DTMF digits. Now due to any reason, Call Forward can not set.

So can we identify this error and give indication to the user that Call Forward cannot set? Is it possible to detect the digits using any symbian API or in GSM Module during active call at caller side? (If Enterprise system gives error indication using DTMF digits) or is there any method to do this?

Thanks.

[Maveric]

Hi rakesh1809,

If you are after detecting digits as DTMF, afaik there is no such lib for this by default.

Maybe you could check the call recording API and read the stream of audio samples, (one
example here)

http://developer.symbian.org/wiki/in..._Tuner_Example

...then correlate the samples against the reference frequencies.

Best Regards,