Re: [Alsa-user] ??simultaneous playback on alsa devices in general??

[Frank B. <fb...@fo...>]

Hallo,
Stefan Kombrink hat gesagt: // Stefan Kombrink wrote:

> When I used alsa in earlier stages i needed to run "artsd" to get simultaneous 
> playback (e.g. for xmms and some sound events...)
> 
> But suddenly my alsa driver seem to support multiple writes on /dev/dsp as 
> well!
> 
> However, this is not true for every sound card: SB Live + Maestro3 does, but 
> I810 doesn't.

The SB Live chipset mixes in hardware. 

> Now my question: What does this functionality depend on?
> Is it in fact possible for every sound card supported by ALSA, it would just 
> need to be implemented, or is it an hardware isse, that some cards will and 
> some won't.

You might want to upgrade to 0.9.1 and use the dmix plugin. It does
mixing of multiple sound streams inside of ALSA. You can select it as
a device like the "default" or "hw:0" PCMs, you might know already.
It somehow like 

$ aplay -D dmix some_long.wav &
$ aplay -D dmix another.wav 

I don't remember the exact syntax at the moment...

ciao
-- 
 Frank Barknecht                               _ ______footils.org__