Re: [linux-audio-dev] Acoustic echo canceller released

From: Jean-Marc Valin <Jean-Marc.Valin@email-addr-hidden>
Date: Sun Jun 05 2005 - 20:15:30 EEST

Le dimanche 05 juin 2005 à 13:01 +0200, Benno Senoner a écrit :
> Hi,
> cool news about the echo canceller.
>
> some questions:
> I've found this algorithm on the web (but I did not test it)
>
> http://home.arcor.de/andreadrian/echo_cancel/draft-aec-03.txt
>
> How do you think your's and the one above compare quality wise ?

I am aware of this AEC and have talked to Andre Adrian. He tested both
AEC and found that aside from the fact that his AEC does a high-pass at
300 Hz, my AEC performed better for both double-talk-detection and echo
attenuation. It also takes half the CPU his AEC requires.

> Do linux telephony apps like linphone, gnomemeeting etc already have
> echo cancellation built in ?
> I guess not.

Not yet because it's really recent, but I talked to Damien Sandras
(Gnomemeeting author) and Simon Morlat (Linphone author) and both seemed
willing to integrate it. I think Steve Kann is currently integrating it
in aixclient.

> Perhaps it would be handy if you made a shared lib out of your echo
> canceller (or provide a c file
> with a simple API like in the link above) so that linux telephony apps
> can easily integrate it
> (and it should work for any codec not just speex).

Even though the AEC is part of Speex, it does not depend on the codec at
all. Also, I updated the Speex manual for info on how to use it. The
manual on the site is still old, but the new one is included in release
1.1.9 (or you can get it from svn at
http://svn.xiph.org/trunk/speex/doc/manual.pdf ).

        Jean-Marc

> Thoughts ?
>
> thanks,
> Benno
> http://www.linuxsampler.org
>
>
> Jean-Marc Valin wrote:
>
> >Hi,
> >
> >I thought this could be of interest to some people here. I have just
> >released an acoustic echo canceller as part of Speex 1.1.9
> >(http://www.speex.org/). So far, I have tested it on 8 kHz, but it
> >should work for other sampling rates. It uses the MDF algorithm and
> >(optionally) residual echo cancellation in the spectral domain. If
> >anyone is interested in making an ALSA plugin out of it, I can provide
> >assistance. Oh, and it's released under the (revised) BSD license.
> >
> > Jean-Marc
> >
> >P.S. In case some noticed, there was an echo canceller in Speex before,
> >but this is the first version to actually work in real conditions
> >(double talk and all).
> >
> >
> >
>
>

-- 
Jean-Marc Valin <Jean-Marc.Valin@email-addr-hidden>
Université de Sherbrooke
Received on Mon Jun 6 00:15:05 2005

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