[pulseaudio-discuss] Rhythmbox and Pulseaudio: per-application volume adjustment causes major ruckus

[Jud Craft]

On Tue, May 26, 2009 at 6:01 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> The control flow should go like this:
>
> user changes volume in rb UI -> rb forwards that as sink input volume
> change to PA -> PA applies it to the stream -> PA forwards it via the
> flat vol logic to the sink volume.
>
> RB should not never look directly at the sink volume. Only ever at the
> sink input volume.
>
>> So, for example, moving the Main Volume to 88%, will cascade back into
>> Rhythmbox, reducing the in-app volume by over 50%.
>
> That sounds like a bug. Could you please file a bug?
>

Forgive me, but from what you just described, either I believe you
intend it to be that way, or I'm not sure about your logic flow.

If Rhythmbox forwards its volume to PA, and PA then adjusts the stream
volume of the RB app, which would then change the main sink (output)
volume, then obviously changing the Rhythmbox in-application volume is
going to change the stream volume in Pulse, and then muck with my main
system output device (sink, I believe) volume.

I'm not sure if you agree with me, but alright.  I just got a
gnome-bugzilla account, I'll take a look at the rhythmbox page and
file a bug.

Also, Banshee changes its volume too, but not as dramatically.

Whenever I pause/play or change tracks in Banshee 1.4.3, the volume
will usually shift a couple of percents.  For example, if I set system
volume to 88%, then when I press play it Banshee, it hops to 84%.  And
then, when I press stop in Banshee, it restores itself to 88%.  It
usually only jumps around 2-4% when I use Banshee, and always jumps
back when I'm done playing.

I have no idea why it should do that (maybe it's rounding down to a
certain dB?).  I'm sorry I can't talk in anything but percents, but
I'm really not that curious about the ALSA dB scale.  I'm just curious
why the stream volume is changing at all in Rhythmbox or Banshee.  I
set the stream volume in _one_ place, and I don't want anything else
changing it (if that's reasonable).

I did note -- much to my delight -- that disabling the flat volumes
fixes this problem.  Rhythmbox is still changing it's stream volume
all over the place, but at least it doesn't effect the main system
(sink) volume anymore.  And Banshee behaves perfectly.