A thread on the Linux kernel mailing list
drew my attention since it deals with a problem that had me annoyed for a long time: Not being able
to have two applications playing a sound at the same time on my notebook, which has an Intel AC97
Soundchip. The alsa kernel drivers do not support multiple streams on hardware that doesn’t do it,
so there hasn’t been software mixing available in kernel. The upcoming release of alsa however does
support these kind of advanced features
This problem is fixed with the upcoming ALSA 1.0.9 release - dmix will "just work". It's been a big area of development lately.
I have been playing around with my alsa configuration a little in order to see if the
bits suggested there would work for me – and indeed – I now can have XMMS running and mplayer using
my sound chip (with the snd_intel_8x0 kernel driver) at the same time. The dmix setup didn’t pose to many problems
to me, but you can of course just wait until your favorite distributor does it right for you.
Now let’s push the skype– and [insert random software that
still doesn’t support alsa here]- developers to use alsa since the OSS layer and also the alsa
OSS emulation don’t support all that shiny dmix magic. Mixing is done in userspace, so not using
alsa-lib means no fun.