[wellylug] Re: wellylug Digest, Vol 3, Issue 31

[pete at marchingcubes.com]

Some things to know:

There are 2 types of sound card supported by Linux. Those that have
drivers which support multiple opens on /dev/dsp (either through ALSA OSS
emulation or via OSS directly), and those that don't. Those that do
include the Sound Blaster Live/Audigy, and those that dont include i810
and most budget cards.

If you are using OSS drivers, your sound card cannot be shared between
applications if does not support multiple opens on /dev/dsp.

If you are using ALSA drivers, the situation is different - ALSA 1.0.9+
supports multiple applications accessing any sound card transparently, or
so they claim.

ALSA before  1.0.9 can be made to do this, but it will take a lot of
tinkering with .asoundrc etc. to get the dmix plugin to work

KDE and GNOME make use of sound servers (esd and artsd respectively) to
get around the lack of a sharable sound device - this is a single program
that opens the sound card, and then other applications send audio streams
to it to be played - in this way multiple sounds can be mixed while only
one process has /dev/dsp open.

It sounds like you are running artsd (the KDE sound server) on a machine
that does not support multiple opens on it's sound device, due to having a
budget audio card and either not using a very recent version of ALSA, or
using OSS.

As such, artsd has exclusive use of the sound card, and xmms will not play
unless it is configured to use artsd.

You can either turn off artsd (The sound server in the KDE control panel),
and configure xmms to use OSS or ALSA (depending on which drivers you are
using) directly, or you can leave artsd running, and configure xmms to use
artsd.

If this sounds complex and annoying, thats because it is. Linux sound
systems are improving but as far as ease of use and discoverability for
end users go, its not ideal.

Let me know if this helps, or if you need further clarification on any of
this.

-Pete



> Hi Chris,
> I've tried all your susgetions and they don't work, thanks anyway. Are
> you able to visit me tonight to help me out in person?
>
> Cheers,
> Steve
>
> On Wed, 23 Nov 2005 09:37:40 +1300 (NZDT),
> wellylug-request at lists.wellylug.org.nz wrote:
>> With Debian ensure that /dev/dsp & /dev/mixer is readable and writeable
>> by the audio group, and that the user you are trying to use XMMS with is
>> part of the audio group..
>>
>> Personally, and I know this should not be done, but I chmod
>> 777 /dev/dsp* and /dev/mixer* just stops issues like that coming up :)
>>
>> Also you might want to check out what output driver you have selected..
>>
>> In the left hand corner, where, O A I D V are, right click and select
>> Options, and then preferences and check that the output driver is set to
>> your sound options.
>>
>> OSS Driver or ALSA Driver...
>
>
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