Displaying 2 results from an estimated 2 matches for "sampofs".
2005 Nov 11
0
Re: aec
...akers).
On each event (sampling capture position passed a marker in the buffer):
- Fetch hardware sample-accurate sampling position of card A and B as PosA
and PosB.
- Copy 320 samples from buffer of card A at offset WantPosA into "mic
input".
- Calculate "negative offset" SampOfs = PosA-WantPosA.
- Copy 320 samples from card B at offset PosB-SampOfs into "speaker
input".
- WantPosA += 320
- Wait for next event and repeat.
This means that even if the cards drift a little (and they do, even with
identical cards), the drift is compensated for. Kind of.
The down...
2005 Nov 11
4
Re: aec
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