[gobolinux-users] Audio recipe advisory

[Lucas C. Villa Real]

On 2/21/07, Benjamin Bruheim <grolgh at gmail.com> wrote:
> Hi,
>
> I did some research and wrote up a piece for the wiki. I would like
> your comments on this:

Hi there Ben. Sorry for the late reply, but I was waiting until I
could give a special attention to this message.

> ALSA has for a while supported audio mixing through the alsa dmix
> plugin. With this in mind:
>
>     * Always enable ALSA support.

Ok.

>     * You might even want to disable OSS support if the applications
> resolves the default API the wrong direction.
>     * If an application supports JACK, please enable this support and
> add JACK to the dependencies.

Ok.

>     * esound (ESD) is legacy, as is ARTs. Do not make these required.
> More on this below.
>     * Some KDE apps do not work without ARTs. This is imho a bug from
> their side.
>
> I might want to add that there's a huge problem with KDE's ARTs deamon
> that makes it hijack ALSA. For this --without-arts should be supplied
> to the configure scripts for KDE packages (if it exists). There is
> however a (current) side-effect of this; noatun will stop working,
> thus movie previews will stop working (!!). This is to be fixed by KDE
> 4 or earlier.

But well, we're on KDE 3.5.6 right now.. I also dislike ARTs, but I
think we must keep using it until their packages are fixed to live
fine without that dependency. I'm going to compile KDE for the
incoming 014 iso this week (it's the next package in my queue), so I
would really like to do the right thing, without compromising KDE
apps.

By the way, I can also remember at least from Audiofile. Is there any
important application depending on it nowadays? Audiofile's latest
release dates from 2004..

> And, lastly. What we sound-dudes love is low latency. Thus it is
> recommended to use these patches:
> http://people.redhat.com/mingo/realtime-preempt/
> These allows latencies below < 30ms and makes linux a viable platform
> for live playback. The inclusion of this patch is usually what sets
> audio-distros apart from the rest. Now, if gobo was to have an
> official set of patches applied ....

We always try to avoid filling recipes with non-strictily necessary
patches. However, given that Mingo's work is constantly being updated
(and probably will be merged soon), I think this can be plausible. I
know that at least Hisham would be glad to have such feature in, as he
also used to work on audio on his PC.

Is there a way to compile this as a module, or does it only compiles
as a built-in? I ask this because I'm afraid that if the patch is
somehow defective all the sound infrastructure will be compromised,
and a new kernel without realtime-preempt should be needed.

-- 
Lucas
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