[sip-comm-dev] echo cancellation

Koch Michael MKoch at rowa.de
Tue Nov 20 15:27:21 CET 2007


Hi Damencho!

I tried your code today. It took some massaging to get it to work under
Windows. Unfortunately, my result was the same as when I tested echo
cancellation with the speex command line tools themselves: the sound quality
was degraded and the echo wasn't cancelled. Does echo cancellation work with
your setup? Did you change any of the parameters to make it work?

These are the things I did to make the code work on Windows XP
* Build the current svn version of speex using cgywin (with the -mno-cygwin
flag).
* Build jspeex using cygwin (with the -mno-cygwin flag, using info.txt as
base).
* Modify the System.loadLibrary calls in SpeexLib. The lib names are
different when compiled with cygwin. Also, the speex lib seems to be
separated into speex and speexdsp now.
* Set the sample rate of the audio capture device to 8000, since the Windows
default is 44100 and that doesn't work with the echo cancellation plugin.

Thanks!
Michael Koch


> Hi Michael,
> 
> Sorry for the delay! Here is what we have done about echo 
> cancellation.
> http://www.sip-communicator.org/echo/sip-communicator-echo.tgz
> http://www.sip-communicator.org/echo/JNI2.tgz
> 
> The first archive is the modified sip-communicator source I 
> was working 
> on. The second one contains source for the native part.
> Most of the modifications are in MediaControl.java, 
> CallSessionImpl.java 
> and in the packages 
> net.java.sip.communicator.impl.media.codec.audio.echo and 
> net.java.sip.communicator.impl.media.codec.audio.speex.impl.Sp
> eexLib.java
> Let me know if you have any questions.
> This is working under linux, but I couldn't make it work on 
> windows as 
> there are problems with capturing media.
> 
> Good luck!
> damencho
> 
> Koch Michael wrote:
> > Hi Emil!
> >
> >   
> >> Hello Michael
> >>
> >> Koch Michael wrote:
> >>     
> >>> Hello Emil, Sergei!
> >>>
> >>>       
> >>>> We (mostly Damian actually) have been working on echo 
> >>>>         
> >> cancellation for
> >>     
> >>>> some time now. We have been using the speex utilities for 
> >>>>         
> >> this. So far
> >>     
> >>>> we have managed to get something working on Linux but the 
> >>>>         
> >> situation is
> >>     
> >>>> far from being ready for integration in the source code, and 
> >>>> it doesn't
> >>>> work on Windows or Mac OS X.
> >>>>         
> >>> This sounds really interesting. We need echo cancellation for our
> >>> application, so I could spend time working on it. Do you 
> >>>       
> >> think it would make
> >>     
> >>> sense if I have a go at the code, or would you rather not 
> >>>       
> >> publish it at this
> >>     
> >>> state?
> >>>       
> >> The thing is that it requires substantial modifications in 
> >> the existing
> >> code of the media package so we can't commit it until it's 
> >> fully tested
> >> or else it would probably break everything. I don't know 
> whether we'll
> >> be able to commit soon since the project is on hold at the 
> >> moment, so we
> >> might as well send it to you.
> >>
> >> Let me know if you'd like this.
> >>     
> >
> > Yes, I'd be interested. I'd like to try out if it works for 
> our setup. If
> > yes, I could take the time to work on the code to do it "properly".
> >
> > Regards
> > Michael Koch
> >   
> 
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