Re: Notes from Sound BoF at GUADEC 2008

[Lennart Poettering <mztabzr 0pointer de>]

On Tue, 15.07.08 18:50, Rodrigo Moya (rodrigo gnome-db org) wrote:

> I was thinking about just changing the current gnome-volume control and
> applet to use pulse/libcanberra directly. I don't think there is need to
> write it from scratch, even if we want (yes, we do) to change it as per
> the topaz mockups

I guess that's up to the one implementing this. I am happy with
either. I just wonder if it really makes sense to port the current
g-v-c code over, since PA and classic hw devices are just too
different. Also, it might make sense to keep the current g-v-c around
for those distributors who don't want to adopt PA (Solaris, ...).

> >        Vincent:
> >            1. Check with people (i.e. Solaris, ...) if it is OK to
> >               link against libpulse directly from some very specific 
> >               desktop applications (such as g-v-c) instead of always 
> >               going through some kind of abstraction layer (i.e. 
> >               GStreamer, libcanberra, ...).
> >            2. Ask KDE folks about how to proceed with PA and lib
> >               canberra 
> >      
> for opensuse 11.1, we are going to use PA for the whole distro, even for
> KDE, where (as far as the KDE guys I've talked with say) they will be
> using just the gstreamer backend. I don't think they would want to
> rewrite/remove phonon code just to accomodate PA/canberra. We can
> probably convince them to have a libcanberra-based backend that will,
> hopefully, replace their ALSA/GStreamer backends.

BTW. The PA backend for Xine should work perfectly fine. That's how we
ship KDE on Fedora.

I brought up libcanberra on the kde mailing list. They love their
knotify, and don't have anything like input feedback sounds. I don't
see them adopting libcanberra anytime soon. Noone in the KDE camp
showed much interest in adding something like this to Qt/KDE. 

> >         Lennart:
> >            1. Release pa 0.9.11, so that Bastien can actually make use
> >               of the property support of PA (i.e. icons for audio apps
> >               in volcontrol)
> >

> when are you going to release? I'm testing 0.9.11 packages now, and it
> seems to work pretty good. Anything I should be testing in detail?

Sometimes the timing interpolation runs amok as it seems. The two
remaining bugs on my list are mostly internal API stuff, which I need
to fix so that it won't break later on.

> > Also, we hoped that we can convince Rodrigo to write the other sound
> > config dialog page, which would allow configuration of the default
> > devices for special roles. Before this can be started, Lennart needs
> > to do his items on the list first, however.
> > 
> I have allocated time to work on PA for the next few weeks, but I don't
> see (or understand) what do we need this for, we already have it in the
> sound capplet, or are you talking about something different?

Yes, it already is available in the dialog. However, it currently
configures only the gst sink to use. Unfortunately only a subset of
audio passes through gst right now. The idea is to configure PA
directly, so that all non-gst streams are routed properly too. This is
not high-priority however, since almost no application tags its
streams with the proper role right now (i.e. "video" vs. "music"
vs. "voip", ...) And of course, PA doesn't have any API for
configuring such mappings right now. All mappings happen implicit
right now: PA remembers where the route was the last time and you then
can fix them by moving streams to different devices.

> What I would really like to do is to have a better looking paprefs/paman
> GUIs, so what are the plans there? Should all that functionality just be
> in the gnome-volume-control capplet from Bastien?

I think paman/padevchooser need to die. paprefs is a trivial application. Fixing
it would probably just require dropping the white bar.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4