[ntp:questions] Re: Audio refclock+linux+soundcard = yuck

Tim Shoppa shoppa at trailing-edge.com
Mon Sep 29 17:50:06 UTC 2003

Ulrich Windl <Ulrich.Windl at RZ.Uni-Regensburg.DE> wrote in message news:<m3lls7hpbs.fsf at pc5234.klinik.uni-regensburg.de>...
> shoppa at trailing-edge.com (Tim Shoppa) writes:
> > the digits.  BUT... the offset is circa 600 milliseconds!  Now a
> > ...
> ...
> advice. Usually sound cards have buffers, and to unload the CPU, an
> interrupt is only created if that buffer is mostly full (or
> empty). Maybe you can control the threshold...

That seems to be a good road to go down.  I'm using ALSA and I know that
the buffer size is 4096 bytes... which means (at 8kHz sampling rate) 512
milliseconds right there.  There seems to be some means for configuring
this buffer size although I have yet to figure out exactly how to do
it, it seems to be beyond the stock alsactl command-line too, I 'll probably
have to put it in the audio.c source at initialization time.


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