[ltp] Sound devices (alsa,dmix, and dev/dsp)

[Richard Neill]

Dear All,

In Mandriva 2006, the alsa dmix plugin is enabled by default. This means 
that any applications which use ALSA as the output (and not artsd or 
oss) can happily co-exist.

This works great if for example, you want to hear sounds from system 
notifications at the same time as playing a sound, or you want (for some 
crazy reason!) to play 2 mp3s simultaneously, or just generally to make 
sure that 2 applications don't fight to the death over the sound card.

However, even though the sound driver is ALSA, the /dev/dsp device is 
not mixed. So any of the older programs (eg /usr/bin/play) can block all 
the alsa programs.

My question is: is there any way to change the oss emulation, so that 
multiple instances of /dev/dsp can be opened simultaneously? Why can't 
alsa transparently do what it does with dmix, but with /dev/dsp ?

Yes, I know about artsd, but artsd adds lots of startup latency, and 
there is also soundwrapper, but it seems to crash lots.

Thanks,

Richard






-- 
rn214@hermes.cam.ac.uk  **  http://www.richardneill.org
Richard Neill, Trinity College, Cambridge, CB21TQ, U.K.