FESCo Meeting Summary for 20090424

Adam Williamson awilliam at redhat.com
Fri May 1 03:38:23 UTC 2009


On Thu, 2009-04-30 at 19:47 -0700, Adam Williamson wrote:
> (btw, the digital output issue is an interesting one. Presumably the
> PulseAudio folks will tell us that, if we want to switch from analog
> to
> digital output, we should use pavucontrol, right? So what's that? Two
> GUI applications to do the same thing...)

I rather want to amplify on this one, because I rather think I've hit a
winner. :)

what's pavucontrol?

to quote rpm -q pavucontrol:

"PulseAudio Volume Control (pavucontrol) is a simple GTK based volume
control tool ("mixer") for the PulseAudio sound server."

Why, it's a volume control tool! Isn't that exactly the same thing as
gnome-volume-control? Isn't the whole objection to including
gnome-alsamixer or gst-mixer that it's a terrible idea to install more
than one volume control tool by default?

Do we install pavucontrol by default? Why yes, yes we do.

http://cvs.fedoraproject.org/viewvc/comps/comps-f11.xml.in?revision=1.210&view=markup

there it is, right in the Sound and Video group, which is installed by
default in the desktop spin (and the desktop spin doesn't override it
out of there):

<packagereq type="default">pavucontrol</packagereq>

so why do we do this kind of interface insanity? Why would we install
*two* whole volume control applications for pulseaudio?

Why, because pavucontrol exposes useful functionality that
gnome-volume-control doesn't.

Here's Lennart helpfully explaining to me in the initial bug report -
491372 - that selecting between analog and digital output isn't a
problem, because PulseAudio handles it:

"Adam, you are misunderstanding how SPDIF in ALSA works. The special
device "spdif:" will toggle all mixer controls appropriately. It will
hence work properly an all cards -- and if it doesn't it's an ALSA bug.
Hence the profile logic PA exposes should provide *complete* SPDIF
experience -- fiddling with low level alsa mixer controls should never
be necessary."

Note that "the profile logic PA exposes" makes "fiddling with low level
alsa mixer controls" unnecessary. Great. But how is this profile logic
exposed? Does gnome-volume-control do it? Why no, no it doesn't. You
can't pick profiles with g-v-c. 

But that's okay! No problem! You can do it with pavucontrol, and that's
installed by default!

Soooo - it's fine to have pavucontrol and gnome-volume-control installed
by default, because pavucontrol is an alternative graphical volume
control application that exposes useful functionality which is not
exposed by gnome-volume-control.

However, the suggestion that an alternative graphical volume control
application like gst-mixer or gnome-alsamixer should be installed by
default because it'd expose useful functionality which is not exposed by
gnome-volume-control is a terrible, terrible idea. It'll confuse people
to death, and it only covers corner cases!

Uhhh...okay.
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Fedora Talk: adamwill AT fedoraproject DOT org
http://www.happyassassin.net




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