echo cancellation
 

Hi:
I am developing an IP Phone on ARM(samsung 6410; CPU:667MHZ), and use lib

mediastreamer.2.6.0 for audio
communication, but now the echo occur while talking. In the lib

mediastreamer.2.6.0, I find a filter can
do echo Cancellation by calling lib speex. I active it to filter the

collected voice, but the telephone
receiver can't hear any voice. Maybe I setup parameters wrong, the

parameters are as follow:

int ec_tail_len = 100;
int ec_delay = 20;
int ec_framesize = 0;
if (use_ec) {
stream->ec=ms_filter_new(MS_NEW_SPEEX_EC_ID);
ms_filter_call_method(stream-

>ec,MS_FILTER_NEW_SET_SAMPLE_RATE,&pt->clock_rate);
//inec_tail_len = 100;
//ec_delay = ;
if (ec_tail_len!=0)
ms_filter_call_method(stream-

>ec,MS_ECHO_CANCELLER_SET_TAIL_LENGTH,&ec_tail_len );
if (ec_delay!=0)
ms_filter_call_method(stream-

>ec,MS_ECHO_CANCELLER_SET_DELAY,&ec_delay);
if (ec_framesize!=0)
ms_filter_call_method(stream-

>ec,MS_ECHO_CANCELLER_SET_FRAMESIZE,&ec_framesize) ;
}

Expecting anybody can give me some advices to cancel the hateful echo.
Best regards!

Good echo cancellation is very tricky.

The easy way is to turn off the speaker when you detect cadence on the mic or turn off the mic when detecting cadence on the speaker. Do either one but no both.

Thank you all the same!