[Speex-dev] problem with echo cancellation

[Jean-Marc Valin]

Hi Julia,

Version 1.2-beta1 has a bug in the echo canceller. Try either svn or
1.1.12 -- or apply this patch to 1.2beta1:
https://trac.xiph.org/changeset/11882

	Jean-Marc

julia rg a écrit :
> Hello Jean-Marc,
> 
>  
> 
> I solved the variable delay problem, but I still have trouble with
> speex_echo_cancel(). When i try testecho.c with clean speech for far-end input
> and same speech with attenuation, a bit of reverb and 50-150 ms delay, all this
> done in sound editor, for mic input, i get 5-8 db attenuation.
> 
>  
> 
> But when i use the same speech played and recorded for mic input, i see about 5
> db of attenuation only if i remove the delay (150ms) at the beginning of mic
> input file to make far-end and mic input files to go almost “in sync”, and even
> in this case there’s almost no attenuation during about a second after pauses in
> speech. Looks like the filter re-adapts after each pause. When the delay is at
> least 50 ms, the output of echo cancellation doesn’t differ much from mic input.
> 
>  
> 
> I use speex1-2beta1 version, and i applied the patch you suggested. I use a
> sampling rate of 8000 which i have set with speex_echo_ctl(),  a frame size of
> 128 and tail length of 2048. I have tried other tail lengths (640, 1024, 4096)
> with no significant effect. I use the same soundcard for capture and playback,
> and quality speakers and microphone to avoid nonlinear distortions.
> 
>  
> 
> How much attenuation can the echo canceller normally produce? Is there anything
> that i'm doing wrong? Getting this to work is very important for me,
> 
>  
> 
> Thanks a lot!
> 
>  
> 
> Julia
> 
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