[Speex-dev] Time Delay Estimation
jean-marc.valin at usherbrooke.ca
Thu Jun 7 16:54:49 PDT 2007
> Does the echo canceller maintain some data structure that I might be
> able to use if I wanted to estimate the amount of delay between the
> near-end and far-end signals? I'd like to be able to do this in order to
> optimally align the signals before passing them to the canceller. There
> seem to be many milliseconds of latency in a Wintel audio subsystem and
> I would like to accurately compensate for that rather than just using a
> huge echo tail.
> I would guess that the adaptive filter must compute some good data that
> I could use as observations for a tracking algorithm.
If you don't need too much accuracy, you can look at the prop array.
The index of the largest element in "prop" will give you the delay in
frames. If you need more accurate, then you'll need to convert the
frequency-domain weights (W) tp time domain and look for the max.
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