Linux ALSA sound bug

 
Whenever I try to play a sound in Etoys on Fedora 10, the VM logs a  
notice:

soundStart: snd_add_pcm_handler: Function not implemented

This has been reported a couple of times but did not make it to this  
list yet, apparently:

        http://tinyurl.com/c4kmta

A workaround is to force using OSS instead of ALSA using the -vm-sound-
OSS option.

I filed this at

http://bugs.squeak.org/view.php?id=7328

(wondered why it was auto-assigned to Tim - maybe Dave would be a  
better taker now?)

- Bert -

It's possible the hardware (DSP?) does not support interrupts needed
for triggering the callback so that function is not implemented. For
others with a similar problem if OSS does not work then checkout the
dsp wrapper for another sound server, eg, "esddsp" and "padsp" for
ESD/PulseAudio resp.

DOC

On Wed, Apr 1, 2009 at 2:38 PM, Bert Freudenberg <[hidden email]> wrote:

It is a known problem.

Colin Guthrie wrote: "Yeah, this simply wont work with pulse in it's current form, nor with other
ALSA plugins for handlings certain things slightly out of the ordinary.

The snd_async_add_pcm_handler() is not considered part of the "Safe" alsa API.

Lennart recently wrote a good guide about this:
http://0pointer.de/blog/projects/guide-to-sound-apis.html

From the section:
"You want to know more about the safe ALSA subset?"

"Do not use "async handlers", e.g. via snd_async_add_pcm_handler() and friends.
Asynchronous handlers are implemented using POSIX signals, which is a very
questionable use of them, especially from libraries and plugins. Even when you
don't want to limit yourself to the safe ALSA subset it is highly recommended
not to use this functionality."

Disable PulseAudio or to write a plugin "vm-sound-PA" for works with PulseAudio
(use this example: http://0pointer.de/lennart/projects/pulseaudio/doxygen/examples.html )

Bert Freudenberg wrote

 
Whenever I try to play a sound in Etoys on Fedora 10, the VM logs a  
notice:

soundStart: snd_add_pcm_handler: Function not implemented

This has been reported a couple of times but did not make it to this  
list yet, apparently:

        http://tinyurl.com/c4kmta

A workaround is to force using OSS instead of ALSA using the -vm-sound-
OSS option.

I filed this at

http://bugs.squeak.org/view.php?id=7328

(wondered why it was auto-assigned to Tim - maybe Dave would be a  
better taker now?)

- Bert -