[Speex-dev] AEC with different soundcards

John Ridges
2009-07-06T21:03:53Z

The problem with different sound cards is that their clocks are not
usually synchronized, and therefore the clock drift adds a non-linear
factor to the audio path. The AEC can only cancel linear changes to the
audio path, and so the AEC never converges.One solution is to measure
the clock drift and resample either the input or output signal so that
they *are* synchronized, and then the AEC can converge. It's not fun,
but it works.

John Ridges