[pulseaudio-discuss] Per-app flat volume adjustment is highly unintuitive, if mathematically consistent.

[Jud Craft]

On Wed, May 27, 2009 at 10:23 AM, Lennart Poettering
<lennart at poettering.net> wrote:
>
> Mate, please just read those mails I wrote yesterday.

I'm working on it, I think I'm getting better.  Note the end of this email...

> PA is not storing stream volumes relative to each other but relative
> to the sink's reference volume.

I guess that's just a unfortunate side-effect of the logic.  Since
only active volumes are rescaled against the reference, it means that
closing an App X and then changing the reference volume with the rest
of the active Apps will make that App X lose its relative position to
the other Apps when it is relaunched.  That's the only thing I don't
like.

I do like the flat logic's intention (use hardware scaling over
software scaling when possible) though.  It sounds like a smart way to
overcome that problem.


I believe you mentioned in your earlier email to me that "setting the
_stream_, not the sink [which I assume means output]" leaves the
reference volume alone.  I think this makes sense, so I will give flat
volumes another shot when I get home today.

So with this explanation, I can understand why Banshee always changes
the volume predictably in flat-volume mode.

I believe, with the sink set to 100%, I must have set Banshee to
something like 92% (while some other app was playing 100% relative to
the sink volume).  Thus the sink was 100%, and Banshee was 92%.

And then I changed the sink volume (thus the reference volume) to near
90%.  I closed the other app.  This made the sink match Banshee's
volume (which by that time was 0.92*0.9 = 83%).  So, with my reference
volume set to 90% and Banshee set to 92% of that, this means that when
playing, Banshee will have a stream factor of 83%, and the sink meter
matches this while I play.  Whenever I cease playing, the sink will
resume displaying the reference volume of 90%.

Do I have it correct?  And I will add, that this behavior (the sink's
visible volume constantly jumping around, even if the reference stays
at 90% internally) is what I find a little confusing.

However, if, as you say, the Sound Events were treated as any other
application in Gnome-Volume-Control (and thus the sink volume matched
them when that stream was set to 100%), this would provide nearly
identical behavior to Vista, as far as I can tell, since I often
adjust all of my apps relative to the Events volume in Vista (which I
believe is how I must have achieved what I do in Windows).