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

[Matt Prazak]

--- Jon Trulson <jon at radscan.com> wrote:
> On Wed, 23 Jun 2004, Matt Prazak wrote:
> 
> > ... 
> >
> >   Audio Error:  BadValue
> >   Request Major code 24 ()
> >   Error Serial #9
> >   Current Serial #47
> >
> 
> 	This is Au_WriteElement.  Out of curiousity, have you tried just
> using auplay (on solaris) to send a wav to a remote nas server
> (solaris->linux)?  Does that work?
>

Using auplay does yield some interesting results:

  - Playing an 8000Hz mono .au file, as in /usr/demo/SOUND/sounds/*.au
on Solaris _does_ work on the remote Linux server.

  - Playing a 44100Hz stereo .wav to the remote Linux server file also
_does_ work.

  - Using the libao NAS plugin in ogg123 to send a 44100Hz stereo Ogg
Vorbis file to the remote Linux server still generates the BadValue
error.

I guess there must be something subtle about how the ogg123 or the
libao NAS plugin interacts with the remote server that's different than
auplay.

> 
> 	Unfortunately, I know next to nothing about the ausuni module - it
> was written by Charles Levert, whom I haven't heard from in a couple
> of
> years.  The code does mention your chip specifically, so that's
> encouraging.
> 
> 	There do seem to be a lot of tweakables in there though -
> delayed_trigger seems interesting.
> 
> 	It's also worth looking at whether BSD_SIGNALS is being set/used
> properly.  There's some strange stuff there.
> 
> 	I would first see if auplay and friends have these problems too.
> Did you find any interesting/related by googling radscan.com? (ie:
> 'delayed_trigger site:radscan.com').. There might be some hints in
> the
> list archive somewhere...
>

Using auplay with nasd on Solaris does work for the 8000Hz mono .au
case, generally works with limited dropouts/static for the 44100Hz
stereo .wav case, but there is still the choppiness for ogg123 with the
44100Hz stereo Ogg Vorbis file.

There is one thing that I found at Google with "site:radscan.com
ausuni":

  http://radscan.com/nas/nas-ml/msg00549.html

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.

Thanks for the good suggestions.


Matt

> 
> -- 
> Jon Trulson    mailto:jon at radscan.com
> ID: 1A9A2B09, FP: C23F328A721264E7 B6188192EC733962
> PGP keys at http://radscan.com/~jon/PGPKeys.txt
> #include <std/disclaimer.h>
> "I am Nomad." -Nomad
> 
> 



	
		
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