[Speex-dev] speex_echo_cancel, please help!

[danflu at uninet.com.br]

Hello,

Need some help using the speex_echo_cancel.
I've read the documentation about the
speex_echo_cancellation function:

speex_echo_cancellation(echo_state, input_frame, echo_frame,
output_frame); 

(in)  echo_state   => speex internal state.
(in)  input_frame  => audio captured by mic.
(in)  echo_frame   => the signal that was played in the
speaker.
(out) output_frame => the signal with echo removed.

I'm under linux and using portaudio as sound API.

My questions are: 

1) How can I grab the signal that was just played
(echo_frame parameter) ?

2) PortAudio can be used to achive this ? If so, how ? If
not what is the best API for grabing the output samples ? 

3) Is there any sample code available on using this function
?

Thank you very much,
Daniel