[Speex-dev] Re: speex

[Jean-Marc Valin]

> I am using speex-1.2 beta1 version. When I am using sample files from
> http://www.surfnonstop.com/~bandit/speex/echocard1/ ,example 6, as input
> to mdf  through testecho the output is fine

That's a good start indeed.

> However when I am recording the signals in echocancel.cxx in
> OpalEchoCanceler::ReceivedPacket taking speaker signal from echo_buf and
> mike signal from ref_buf, echo cancellation is not affective. 

There's many things that can go wrong with AEC in general. First, I
suspect Opal doesn't have very good input/output synchronisation. If
your speakers are low-quality, it can have a big impact because
distortion cannot be cancelled. Any other non-linear element (e.g. noise
gate) in your setup will also have a bad effect. Same thing for doing
record and playback from different soundcards. You can always try the
latest svn version that has workarounds for some bad setups (doesn't do
miracles though) and see if it improves things. If you actually save the
data that goes into the AEC, you might get an idea of what's wrong.

> Can you please tell me how exactly have you recorded the signals. How
> may I record such samples to test the echo cancellation.

No idea how these files were recorded. I can just guess "properly"