[nas] Question regarding performance of playRaw and AuHandleEvents()

[Jon Trulson]

On Fri, 25 Jun 2004, Matt Prazak wrote:

> From: Matt Prazak <prazak_lists at yahoo.com>
> Date: Fri, 25 Jun 2004 19:22:19 -0700 (PDT)
> Subject: Re: [nas] Question regarding performance of playRaw and
>     AuHandleEvents()
> To: jon at radscan.com
> Cc: nas at radscan.com
> X-Spam-Status: No, hits=-4.7 required=5.0 tests=AWL,BAYES_00 autolearn=no
> 	version=2.60
>
> --- Matt Prazak <prazak_lists at yahoo.com> wrote:
> > ...
> >
> > Apparently, everything I have been seeing with the choppy output
> > under Solaris on an UltraSPARC was a known problem back in 2000,
> > but it wasn't resolved (they blamed it on the Solaris kernel driver
> > for Ultra platforms).  One thing I have been seeing is that the
> > problem is definitely related to when SIGPOLL events are being
> > generated for the processAudioSignal() function, so this does seem
> > to corroborate that the kernel driver might not work well at the
> > 44100Hz 2-channel data rate.  However, I don't have a problem
> > playing audio CDs under Solaris nor is there a problem when
> > ogg123 uses a native Sun /dev/audio driver...I'll take a look at
> > the xmcd and ogg123 source code to see why they work well.
> >
> > ...
>
> It seems the other applications that work do so by managing their own
> timing and writing directly to /dev/audio.  They don't rely on SIGPOLL
> at all.  It seems that the solution for Solaris/UltraSPARC (which was
> mentioned in the 2000 thread) is to find a new implementation that
> bypasses SIGPOLL entirely while still fitting in with NAS'
> architecture.  Unfortunately, this is a bit beyond what I can do right
> now.

	Yeah... it should probably use a timer based approch like
auvoxware.  POLL would be the best way, but it does not seem reliable
enough.

	I suppose if I had a sparc I would take a crack at it, but alas...


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Jon Trulson    mailto:jon at radscan.com
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