PA by default

[Bastien Nocera]

On Mon, 2007-08-20 at 23:01 +0200, Lennart Poettering wrote:
> On Mon, 20.08.07 21:37, Bastien Nocera (bnocera at redhat.com) wrote:
> 
> > > GStreamer supports all kinds of interfaces to enumerate sound
> > > devices. gst-pulse supports those. Hence the dialog should work, but I
> > > cannot really say since I haven't testes this. (see above) qThe
> > > gnome-volume-control device selection does work the last time I
> > > looked. 
> > 
> > gstreamer-sound-properties. It's the "Sound" preference.
> 
> Hmm, is not installed on my machine, only gstreamer-properties which
> is not what I am looking for. Hmm, Google doesn't even find any
> mention of "gstreamer-sound-properties".
> 
> Hmm, you probably meant gnome-sound-properties. And update of
> control-center brought it back now. seems to work fine, too.

Yeah, I'm doing too many things at the same time :)

> > BTW, do you want me to change the default sinks in
> > gstreamer-plugins-good? If so, could you file a bug so I don't
> > forget :)
> 
> I checked those and they point to "autoaudiosink" by default, which
> should be enough to get gst-pulse working by default. And is the best
> choice anyway, to make sure that people who think that PA is devil's
> work don't get pissed off needlessly. ;-)

If that makes it work, then fine with me :)

> > > So, what I would like to see implemented is this: ALSA hides away
> > > unncessary volume controls and initializes them to sane defaults
> > > (i.e. "0 dB"), and makes sure there is always a "Master" volume
> > > control which is the actual control for the amplification in HW. This
> > > is what Takashi has started to work on. PA already exposes this single
> > > per-device volume control, and ignores all the rest the hw might
> > > expose. That's volume control #1, the per-device hw-based one. 
> > > 
> > > For volume #2, the per-stream sw-based one: the PA per-stream volume
> > > and the volume adjustment done in GST should be "merged". PA has all
> > > the necessary APIs but Gstreamer needs some non-trivial changes for
> > > this. Right now GST's mixer control is awful and designed with
> > > per-device controls in mind and hardware backends. Hence I am unable
> > > to expose the PA per-stream volume properly in gst-pulse.
> > 
> > Right now, Totem and Rhythmbox have their own software-volume in the
> > pipelines. Handling the "hardware" mixer that PA shows means that Totem
> > and Rhythmbox would need to special-case PA.
> 
> What I would like to see is that gst-pulse would expose a new
> interface on the GstPulseSink element that allows you to modify the
> per-stream volume control. In a way the current volume control
> abstraction in gst is already designed to work like that, but it's for
> per-device controls and totall fucked up anyway.

We're mixing 2 different things. There's the per-stream volume, for the
GstPulseSink for use in gnome-volume-control, and there's detecting that
we have a "stream" volume, for Totem and Rhythmbox.

The former I don't think is very important right now, as long as the
latter is implemented.

A simple read-only property would be enough to handle that. Does MacOS X
present a similar interface for applications to use, or do they
implement volume control by themselves like Totem/Rhythmbox currently do
with the volume element?

If there's something like that in MacOS X, it's a matter of agreeing on
the name of the property.