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

[Lennart Poettering]

On Wed, 27.05.09 11:10, Finn Thain (fthain at telegraphics.com.au) wrote:

> 
> 
> Lennart wrote:
> 
> > 
> > Now, I must admit that this all is a bit hard to grasp. And thus not 
> > exactly the definition of easy to use. We had a couple of discussions on 
> > this very ML about this. So far noone came up with a way to fix this in 
> > a way that would be completely convincing.
> 
> I can't claim to grasp it, but...
>  
> > I think the core problem is that it is impossible to figure out what the 
> > user actually wants. When he increases a volume of a stream he might A) 
> > want it a bit louder then whatever else is currently playing and would 
> > be pissed off if the other stream would get louder at the same time or 
> > B) want it a bit louder because everything that's playing is just too 
> > silent and he would be pissed off if only one stream would get louder 
> > and not all.
> 
> It seems to me that these problems would go away if you accept that 
> boost/compression should not be a function of volume. (Use a seperate 
> module!) If PA can't satisfy audiophiles, then PA will not earn a great 
> reputation with the layman who trusts experts either.
> 
> Every sensible volume control I can think of is conceptually an 
> attenuator, i.e. zero decibels at maximum (even if it is implemented as 
> amplifier gain control internally). That's why a slider is appropriate as 
> a GUI element here. (VLC player notwithstanding. I carefully leave it at 
> 100% and never touch it. The 400% upper bound is both non-intuitive, 
> arbitrary and likely to distort.)
> 
> So, if as you claim, the user "might A) want it a bit louder then whatever 
> else is currently playing and would be pissed off if the other stream 
> would get louder at the same time", I think that user has probably never 
> used a volume control or mixer (i.e. an attenuator). It doesn't make sense 
> (in my mind) to optimise for this unusual situation.

You are misunderstanding the flat volume logic.

In flat vol the hardware volume is always configured to the *maxmimum*
of all stream volumes. And if the streams have different volumes then
some of them will be attenuated digitally, *nothing* will be amplified
digitally.

So, if someone wants playback of exactly one stream a bit louder, then
this will have the effect that the output device volume will be
increased and digital attenuation happens for all other streams.

Which seems to be exactly hat you are asking for, which in turn makes
me wonder what your mail is actually about?

Lennart

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