Mailinglist Archive: opensuse-kde (287 mails)

[Daniel Eckl <daniel.eckl@xxxxxx>]

Am Mittwoch, 4. August 2004 09:23 schrieb Guenter Lichtenberg:
> On Wednesday 04 August 2004 03:35, Marc Collin wrote:
> > hi
> >
> > i can play music, mp3 without problem under kde...
> > but i the kde control center - sound, kde notification sound system is
> > on... but i have no sound when an event happen...
> >
> > same thing for kopete... i receive a message or send one... but no sound
> > happen
> >
> > any idea?
> >
> > i use suse 9.1
> >
> > thanks
>
> Hi -
> 	I had the same problem on SuSE 9.1. I solved it by - strangely enough -
> setting the external player to 'artsplay'. You do this by starting the
> control center and then going to 'Sound&Multimedia'->'System Notifications'
> and then push 'Player Settings' and fill in artsplay.
>
> It is maybe a SuSE 9.1 problem, my PC at work has red-hat and there it
> worked without any external player (as it should).
>
> Hope it helps
> gl

If you find that behavior strange, then you have deficiency in understanding 
the linux sound system.

Nearly all sound chips can only be opened by one sound application at one 
time. Only exception I know are EMU10K1 based soundcards like Soundblaster 
512 or Live! (and perhaps Audigy?)

To get sound from two applications at one, you have to use a sound daemon like 
arts daemon (short artsd).
This daemon opens the sound device and listens for connections from arts aware 
applications. These can connect to arts daemon and give it the sound stream. 
Artsd after that looks if any other application is playing, too and if 
neccessary it mixes all sound streams and then sends the one mixed sound 
stream to the soundcard.

Artsd releases the sound device when not used for some seconds. Then you can 
open your music player and start playing.
If after that an arts-aware app will play sound, it gives sound to artsd, but 
this time artsd cannot open the device. It's blocked by the music player.

So one solution is to get the music player arts-aware, too. Examples are the 
arts plugin for xmms.

Another aproach is more difficult, but it works better, because it has no 
noticable latency (the time between application starts playing and the time 
the sound comes out of your boxes).

You can choose to use alsa as backend for anything. Configure alsa to use the 
dmix plugin (http://alsa.opensrc.org/index.php?page=DmixPlugin). This does 
the software mixing like artsd, but it does it somehow better and faster. If 
someone is in need for further explanation, then ask here on this list.
After that, configure arts to use alsa as backend. If asound.conf is 
configured right, it qill use the alsa dmix plugin.

After that try to switch all other sound applications to use native alsa, too. 
This works wonderful with apps like xine, mplayer, xmms and if you use the 
aoss libraries with LD_PRELOAD (I can explain this further, too), then you 
even can get mozilla, opera and helixplayer / realplayer to use alsa with 
dmix plugin, too.

So, thanks for reading this biiiig mail and I hope I could give some light 
into this ever repeating question.

Greets,
Daniel