[nas] Re: Sound dropouts using ALSA and NAS on Linux

Jon Trulson jon at radscan.com
Thu Aug 24 18:33:01 MDT 2000


On Thu, 24 Aug 2000, Charles Levert wrote:

> Date: Thu, 24 Aug 2000 16:36:15 -0400
> From: Charles Levert <charles at comm.polymtl.ca>
> To: NAS mailing list <nas at radscan.com>
> Subject: [nas] Re: Sound dropouts using ALSA and NAS on Linux
> 
> Hi.
> 
> I wrote the unified Sun Sparc NAS dda (reusing, rearranging,
> debugging, and adding to pre-existing code).
> 
> David Morano <morano at computer.org> writes:
> 
> > > The problem is intermittent dropouts in the playing of a wav file.
> > > They seem to occur at the same points in the sound, i.e., if you
> > > play the sound again you are likely to hear the same pattern of
> > > dropouts.

[...]
> 
> So it may have more to do with the kernel audio driver support for
> 44100 samples/s than anything else.  The driver I am using is from a
> Sun patch for SunOS 4.1.4 that backported Solaris 2.5 stuff.  (The
> original CS4231 driver for SunOS 4.1.4 just didn't work, for those who
> can remember.)
> 

	Yeah...  I ran into a similiar problem on Linux.  I thought I'd
throw a cheapo SB 16 vibra onto one of the linux boxes in my office.  It
was *quite* choppy with lots of dropouts - this on a PIII 733Mhz!  I ended
up having to drop the output sample rate to 22K before it would play
uninterrrupted.  In this case I think it had more to do with the card and
the i820 chipset than the kernel, but my point is these types of things
can crop up and there isn't much NAS can do about it.  

	Note, I got the same dropouts whether I was using NAS or doing the
hw directly.  

	If possible (I've never worked on the sun code) you might try
lowering the output sample rate.  Hmm.  would be nice if the sun and hp
servers also parsed and used the 'outputsection' and 'inputsection'
options in nasd.conf that voxware uses - would be easier to do these types
of tweaks.

[...]

-- 
Jon Trulson    mailto:jon at radscan.com
ID: 1A9A2B09, FP: C23F328A721264E7 B6188192EC733962
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