[Speex-dev] Stream Synchronization for Echo Cancellation

[Tom Grandgent]

Isn't this the same problem described starting at the bottom of 
this page?
http://www.embeddedstar.com/articles/2003/7/article20030720-11.html

Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> wrote:
> 
> > As it says in 5.4.1 of the good book "Using a different soundcard to do
> > the capture and playback will *not* work, regardless of what you may
> > think. The only exception to that is if the two cards can be made to
> > have their sampling clock 'locked' on the same clock source."
> > 
> > It seems to me that it should be possible to achieve synchronization
> > using some combination of cross-correlation, clock skew estimation, and
> > sample interpolation. But there are so many details to consider, I bet
> > it would take a long time to get right.
> 
> When you get that to work, please let me know and we'll publish some
> papers about it. Until then, your best hope is in echo *suppression*
> (i.e. frequency-dependent gain), although even that could be a bit tricky.
> 	
> 	Jean-Marc
> _______________________________________________
> Speex-dev mailing list
> Speex-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/speex-dev