[CM] alsa and snd-6

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
22 Nov 2002 11:16:00 -0800


> > I'm getting lots of buffer underruns in snd with alsa-0.9rc3, both when
> > recording and playing. This must be an alsa issue, because csound also
> > gives buffer underruns when playing directly to devaudio. snd also
> > sometimes segfaults after playing, when first recorded. Now I changed
> > snd to use oss, and this seems to work correctly. I've downloaded the
> > alsa-0.9rc6, but haven't installed it yet. Has anybody else encountered
> > buffer underruns with alsa and does installing alsa-0.9rc6 do any help?
> 
> Hi Matti, how's everything going for you these days ?
> 
> Yes, I still have trouble with my SBLive and ALSA with Snd, so I usually
> compile it for OSS instead. Nando's done a lot of work on this already,
> but I suspect the SBLive is just a very difficult card to work with.

Not difficult but strange. It is asymetric, only supports two buffers
for recording but a lot more for playback. Currently snd assumes that
the audio i/o is going to be symetric, so you are stuck with just two
buffers for playback (before I "fixed" that, recording would not work),
which is not good as snd is not multithreaded with regards to audio i/o.
I obviously need to redo the alsa driver for snd, it is still missing
support for non-interleaved cards. Finding the time is the problem. 

-- Fernando