[Speex-dev] Echo cancellation diagnostic code

[William Zhang]

For the capture1.zip, there was no acoustic path change during the
recording. Nobody is in the near end, it is just a speaker and
microphone sitting on the desk, I was talking
at the far end in another seperated room.   As for the capture2.zip, I
am not sure as
I got it from the web.

Thanks again for looking into the capture and the effort in the echo
canceller diagnostic code.

On 3/23/07, Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> wrote:
> All I can say for now is that:
> 1) My diagnostic tool does funny things that need to be fixed
> 2) It was probably also getting confused by the clicks at the end of the
> files
> 3) There seems to be odd things with your recordings, though I can't say
> what that would be. Are you changing something during the recording by
> any chance? Note that if a person close to the mic of speaker moves,
> that changes the acoustic path
>
>        Jean-Marc
>
> William Zhang a écrit :
> > Definitely! It tells me that my delay is fine but drifting is -15. I
> > use the same onboard sound
> > to record the near end and far end voice. So I can assume it should be
> > fine?
> > But I don't see the any different between input and output the
> > echo_canceller function for this recording.
> > Maybe there is some nonlinearity issue there?  The link of this
> > file(Capture1.zip) is in
> > http://lists.xiph.org/pipermail/speex-dev/2007-March/005390.html
> > There is another record set in the file(Capture2.zip) which I got 141
> > sample delay and drift of 14.
> > I did not record this file so I don't know if it is from the same
> > sound card. The PC simulation
> > only gets about 10 to 15db ERLE.  It could be also a linearity issue.
> >
> > On 3/22/07, Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> wrote:
> >> > Thanks for the great work. It indeed helps to diagnose of echo
> >> > canceller and narrow down the
> >> > problem area.
> >>
> >> Good, so it worked for you?
> >>
> >> > I am not an expert in the signaling processing but I
> >> > wonder if it is possible
> >> > to add the linearity check in the echo_diagnostic function?
> >>
> >> Theoretically, yes. In practice, I'm not sure how accurate it would be.
> >> Do you have any samples you know have non-linear distortion?
> >>
> >>         Jean-Marc
> >>
> >> > Thanks,
> >> > William
> >> >
> >> > On 3/16/07, Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> wrote:
> >> >> Hi everyone,
> >> >>
> >> >> I think this should be interesting to all of those with echo
> >> >> cancellation problems. I finally check in some code to make these
> >> >> problems easier to debug. You'll need to have svn version for this.
> >> >>
> >> >> First, you need to manually define DUMP_ECHO_CANCEL_DATA in the
> >> >> compilation (sorry configure switch for now). With that, the AEC will
> >> >> automatically save the near-end, far-end and output signals to files
> >> >> (aec_rec.sw aec_play.sw and aec_out.sw). These are exactly what the
> >> AEC
> >> >> receives and outputs.
> >> >>
> >> >> >From there, you'll need to start Octave and type:
> >> >>
> >> >> echo_diagnostic('aec_rec.sw', 'aec_play.sw', 'aec_diagnostic.sw',
> >> 1024);
> >> >>
> >> >> (the value of 1024 is the filter length and can be changed)
> >> >>
> >> >> There will be some (possibly) useful messages printed and echo
> >> cancelled
> >> >> audio will be saved to aec_diagnostic.sw . If even that output is bad
> >> >> (almost no cancellation) then you probably have a recording problem.
> >> >>
> >> >> Cheers,
> >> >>
> >> >>         Jean-Marc
> >> >> _______________________________________________
> >> >> Speex-dev mailing list
> >> >> Speex-dev at xiph.org
> >> >> http://lists.xiph.org/mailman/listinfo/speex-dev
> >> >>
> >> >
> >> >
> >>
> >
> >
>