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7328 VM major always 04-01-09 13:36 07-03-09 19:55
bert  
lewis  
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0007328: Linux ALSA sound snd_add_pcm_handler: Function not implemented
Whenever I try to play a sound in Fedora 10, the VM logs a notice:
 
soundStart: snd_add_pcm_handler: Function not implemented

and no sound is heard. This has been reported a couple of times but did not make it to this tracker yet, apparently:

    http://tinyurl.com/c4kmta [^]

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


Notes
(0013149)
lewis   
07-03-09 19:55   
Additional info from ggromko@mail.ru on vm-dev list:

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 [^] )