Speex dev - Oct 2006 - Echo cancellation in speex 1.2 beta1 problem

Hi Speex Developers,

I'm Andrey Zhukov, the developer of PI-CONSULT GMBH company.

Building a voip application that uses your libraries, i have found the strange
problem with the latest version of Speex Libs.
Our application works under win32, and i used before version speex 1.1.12 ( were
built from sources).

It seems i have resolved the known problem with clock drift of audio cards using
the developed Windows compensation algorithm .
(I use sync. call speex_echo_cancel(...).The remain syncronisation between in
and out frames is my own.

The previous 1.1.12 cancellation works moreless well, and after appearance of
new version i desided to try use it.
The result is:
In real condition case 8 from 10 times cancellation is very unstable and starts
generate a noise signal. I think this happens on fast learning stage of EC
algotithm.
When  EC learning stage finished normally (2 from 10 times ) after 2- 5 seconds
cancelletion works better than previous version.

Could you please suggest to do something  to stabilize EC in new version 1.2
beta1?
Do you plan release the new version in nearest time?
Can i help to accelerate resolving the problem (deep investigation, testing or
something else)?


Best regards.
Andrey Z.
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> The previous 1.1.12 cancellation works moreless well, and after
> appearance of new version i desided to try use it. The result is: In
> real condition case 8 from 10 times cancellation is very unstable and
> starts generate a noise signal. I think this happens on fast learning
> stage of EC algotithm. When  EC learning stage finished normally (2
> from 10 times ) after 2- 5 seconds cancelletion works better than
> previous version.
That's a known problem due to a stupid bug in 1.2beta1 (see earlier post
on the list).
> Could you please suggest to do something  to stabilize EC in new
> version 1.2 beta1? Do you plan release the new version in nearest
> time? Can i help to accelerate resolving the problem (deep
> investigation, testing or something else)?
Can you try the following patch: https://trac.xiph.org/changeset/11882
Alternatively you can use the latest svn version (though be aware that
I'm currently shuffling lots of code around in svn).

Let me know if it still doesn't work.

	Jean-Marc