Speex dev - Mar 2007 - Performance of the acoustic echo canceller

It seems like the firefox 2.0 not quite works with hotmail... I am reposting my
message again
with IE for easy readability. Sorry about mess. 
Hi Jean-Marc, Thanks for the suggesting.  I tried the test wtih my recording
file offline through the testecho.
I got the same result(no prepocessor echo suppression) as my recording file for
that live call.
Basically I don't see the difference between input_frame and output_frame.  
As I mentioned in my original post, the echo return loss is about 20db. I guess
the echo canceller
is not really actively cancelling the echo in such condition? But without the
echo sppression/NLP, echo is
still noticable.  I used the same onboard sound card for the speaker and
microphone.  As far as I
can tell,  the delay between echo_frame and input_frame is consistent and about
10ms. I would assume
the synchronization is not a problem.  And I also have some other echo recording
files which has almost 0db echo return loss and about 20ms
consistent delay.  The EC can achieve about 10 to 15db echo return loss
enhancement in this case.
Is it normal?  I would think 25+ db ERLE plus 15+ NLP/ES should make the
residual echo inaudible.
I am not sure about the nonlinearity of those recording files but I would
appreciate it if you could take a look  of those.  I uploaded  them to
http://www.sharebigfile.com/file/101511/capture-zip.html
Capture1.zip is first case, 20db ERL.  Capture2.zip is second case, 0db ERL.
Bunch of thanks!  Regards,William


> Date: Mon, 5 Mar 2007 20:27:39 +1100> From:
jean-marc.valin@usherbrooke.ca> To: espzzh@hotmail.com> CC:
speex-dev@xiph.org> Subject: Re: [Speex-dev] Performance of the acoustic echo
canceller> > Best advice I can give is to record the near-end and far-end
files, pass> them through testecho (disable the preprocessor) and check the
result.> Then check why it's not working (if that's the case). Some
usual suspects:> > 1) Clock drift between capture and playback> 2) Bad
synchronisation> 3) A non-linearity somewhere (bad speakers, noise gate,
...)> > If you try everything and can't find what the problem is,
please upload> the files somewhere and send an email with the links (do not
email the> files directly).> > Jean-Marc> > William Zhang a ?crit
:> > Hi All,
>>  I am working on my master project to port the Speex Acousic
> > Canceller to FPGA. But I am not able to get a satisfied result in
its> > performance whenI integrated it to a SIP softphone as my first
step.
> > > > The SIP softphone calls to a PSTN gateway and lands to my
land line> > phone. I can hear the echo of my every word while I talks on
the> > land line phone. I am using G.711 codec, frame_size 80 and both>
> 1024 and 2048 tail length. The code was compiled as floating point> >
and fixed point in the PC. But none of them help. I made sure the the> >
synchronization between echo_frame and input_frame was stable and the> >
delay is consistant about 10ms. The echo return loss is around 20db> > but
output_frame and input_frame signal is about the same. I even> > tried
Jean-Marc's latest mdf.c from the subversion but no luck.
> >
> > Has anyone test the performance in any other softphones and how well
does> > it work? I have the recording files, anyone would be interesting
in> > taking a look? I wonder if there is something wrong with my
input,> > setup...
>>
> > BTW: did anyone ever try to port the algorithm to hardware?> > I
will do some profiling and implement the most compuation expensive> >
function in the Xilinx FPGA.I would really appecriate if anyone can> >
share some experience or provide adavise and suggest! I like to> >
contribute my work to the Speex project if my project turns out to be> >
good end.
> > Regards,
> > William > >
_________________________________________________________________ > >
Connect to the next generation of MSN Messenger > >
http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-us&source=wlmailtagline>
> > > > > > >
------------------------------------------------------------------------>
> > > > > _______________________________________________
Speex-dev mailing> > list Speex-dev@xiph.org > >
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On 3/6/07, William Zhang <espzzh@hotmail.com>
wrote:
> It seems like the firefox 2.0 not quite works with hotmail...
I think you meant that hotmail doesn't work with Firefox, not the
other way around.  Microsoft employs broken HTML mixed with
proprietary elements targeted solely at their own browser.

Do you want a gmail invitation?  That should solve your problems with
regards to e-mail communication.

Regarding your issue with Speex, have you tried to do the same thing
on another computer?  With both the same and an other mic?  A
different Operating System?  You may nail the problem if you try a
different recording setup.

-Ivo