[Speex-dev] DPLL in aec samples

Dario Andrade dario at ip.tv
Fri Nov 11 10:00:09 PST 2005

May I still try to sync them using some kind of DPLL (digital phase locked
loop) mechanism? Something like
matching clocks and interpolating samples to try to sync them together?
Do the interpolated samples get to be eligible for an aec in your opinion?


> To everyone on the list: do *NOT* attempt to do echo cancellation with
> signals sampled using different clocks. This will *NOT* work. Just a
> 0.1% difference between the two sampling rates (it's sometimes worse
> than that) means that the impulse response drifts by 8 samples every
> second. There's just no way to efficiently track this.  Or at least no
> way that doesn't involve something 100x more complex than what I have
> now. So if you want to use two different soundcards, you should either:
> 1) Have professionals cards connected with a clock sync
> 2) Have an atomic clock in both cards
> 3) Forget about echo cancellation
> 	Jean-Marc

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