[linux-audio-user] Sound servers conflict

[Christoph Eckert]

Hi Kai,


> Actually this is not quite correct. Dmix is part of
> standard ALSA and is thus available on any recent Linux
> system.
>
> You are of course right that dmix is not commonly
> configured to be part of default plugins.

Yep, you're right. It is installed, but of course I meant that 
per default an asoundrc is missing most often.

> But most ALSA 
> apps allow you to specify which soundcard to use (the usual
> implicit choice is 'default'). If you specify "plug:dmix",
> you'll get dmix output in most cases (unless user has
> overridden the asoundrc configuration).
>
> For example:
> aplay -Dplug:dmix foo.wav
> alsaplayer -o alsa -d plug:dmix
> ecasound -i foo.wav -o alsa,plug:dmix

Thanks for pointing this out. I'm still not experienced enough 
concerning ALSA and DMIX. I tried to write an asoundrc (which 
should not only enable DMIX but also order my cards in a 
certain order), but at some point I gave up ;-) .

> This works on my system with vanilla alsa-lib-1.0.4 (quite
> old version in fact) without absolutely no modifications to
> any ALSA configuration files (I don't even have a
> ~/.asoundrc on this machine). So I assume this should work
> out-of-the-box on any system that has recent ALSA (SuSE
> systems, FC2 and newer, Mandrake 10 and so on).
>
> More info at:
> http://alsa.opensrc.org/index.php?page=DmixPlugin

Yeah, I already read it. But still it requires manual work.

So, I thouht about a small script which could create an 
asoundrc automatically, then I tried to tweak the alsaconf 
script, the I saw it needs some rewriting and refactoring, 
and then I gave up ;-) .

> PS I think dmix is _the_ solution for "desktop sound
> mixing". Together with JACK they form a killer combo. :)

Do you use both at the same time? Jack is running all day and 
using DMIX, while maybe artsd or esound is running in 
parallel for desktop audio?

> I 
> use JACK when making music (ability to route audio between
> apps, transport control), and dmix when listening to mp3s
> (wide application support, no need to run nor configure any
> servers; still great performance ... also latency-wise!).

Is DMIX transparent to any ALSA aware application, or does an 
application need some coding to use DMIX, or is it needed to 
invoke the application always with the plug:DMIX parameter?

It would be cool if it were transparent to the user.


 Thanks & best regards


    ce