Re: Linux Audio Conference 2007 impressions

[Stefan Westerfeld <stefan space twc de>]

   Hi!

On Tue, Mar 27, 2007 at 03:15:51PM +0200, Tim Janik wrote:
> On Mon, 26 Mar 2007, Stefan Westerfeld wrote:
> >Here is a short summary of my impressions from the Linux Audio
> >Conference 2007, which I attended. There were official talks, and
> >private conversations with other linux audio developers.
> 
> thanks for the wrapup!
> 
> >Exchanging Ideas
> >================
> 
> >Another point for code sharing could be the code that allows reading 
> >control
> >events from external devices, such as joysticks.
> 
> does Buzztard have some such code already (joysticks in partcular)?

I asked Stefan Kost yesterday on IRC, and his answer was that its not
finished, but he'd inform me once it is.

> >Marc-Andre Lureau and I had some discussion on desktop audio.  As this list
> >isn't really the place to discuss this,
> 
> oh, i wouldn't mind if you extended on that a bit here ;)
> or did you mean to post about that in another forum?

No, I didn't mean to actually start a new discussion somewhere.

> >here are just a few questions (without
> >necessarily being complete):
> 
> >* If Phonon suits the needs of KDE4, is there the need of something
> >  equivalent for Gnome?
> 
> suits it for what? gtk has python bindings already, but that's probably
> not what you mean, or is it?

Phonon is not Python. See http://phonon.kde.org/

Basically, for playing media within _most_ application (90% .. 95%), the
task is really simple: very often you want to just play a sound (like in a
game, or for window manager sound effects), or - if it's something like
a presentation software (think Open Office Impress / KPresenter), you
just want to play a video.

So for most applications, knowing all the details is not necessary. They
just want that their sound effects, and not care about whether the user
is running PulseAudio or aRts or no sound daemon at all, whether the
user's sound card can play multiple sounds at once natively or uses
DMix.

> 
> >* How can everything "just work" out of the box, if you mix KDE4 and
> >  Gnome?
> >* What form could a freedesktop.org standard take?
> 
> a standard for what purpose?

Basically something like

main()
{
   ...
   some_namespace_play_sound_now ("foo.wav");
}

that just works. It may also me themable like:

main()
{
   ...
   some_namespace_play_themed_sound_now ("warning");
}

which could be crossdesktop, so that the sound theme affects for
instance both, KDE and GNOME apps running on the same desktop.

Another thing that may be useful is an PCM stream abstraction (kind-of
like PortAudio). The reason for coming up with something like that is
that in the future it may not be a good idea to tie applications to
PulseAudio in the same way that it has been done with aRts/ESD in the
past.

GStreamer fans may say: simply use GStreamer for everything, but on the
other hand many many applications out there already produce their own
sound as PCM stream(s) (such as BEAST), and not all of them necessarily
would be good candidates for being components of a media framework.

This thread (on the freedesktop list) is related:

http://lists.freedesktop.org/archives/xdg/2007-January/008995.html

and this BLOG entry by the PulseAudio author:

http://0pointer.de/blog/projects/foms-lca-recap.html

   Cu... Stefan
-- 
Stefan Westerfeld, Hamburg/Germany, http://space.twc.de/~stefan