Amarok + PulseAudio: volume control changes global volume

Colin Guthrie gmane at
Tue Jul 6 14:21:46 BST 2010

'Twas brillig, and Nikos Chantziaras at 06/07/10 13:36 did gyre and gimble:
> On 07/06/2010 11:38 AM, Colin Guthrie wrote:
>> [...]
>> So what is this logic? Well, the general premise is that h/w volume
>> control is favoured whenever possible.
> Why?  As I mentioned in another post, lowering hardware volume results 
> in a reduction of bit-depth, and thus sound quality.  PA is free to mix 
> at a higher bit-depth than the hardware supports in order to avoid this, 
> but the hardware can't.

PA mixes the prior to sending it to h/w so doing so before applying
volume changes is clearly going to be better quality.

Essentially the aim is to avoid touching the audio stream if at all
possible and that's what this approach does. As mentioned earlier it's
the same approach taken in the latest Windows incarnations too.

>> So in short, what you are seeing is all expected behaviour in this
>> scenario. Get yourself a PA enabled kmix and drink the kool aid and
>> you'll never need to worry again :)
>> If you really don't like this, disable flat-volumes as previously mentioned.
> Actually my experiment with PA ended and thus I'm not using it any 
> longer.  It didn't provide anything new to me that I didn't have before, 
> but introduced new problems instead;

That's a shame. Be warned that as time marches on, most users and thus
most testing will end up using PA. The power savings (particularly
important on mobile devices) and unification of audio settings are
probably the primary reasons for doing this.

Just like you avoid consolekit and possibly other things that make up
part of a modern, standard desktop, you'll find it increasingly hard to
get support from people involved with upstream projects.

I'm all for experimenting and trying out new things and doing it your
own way etc., but it's important to realise the disadvantages while
stepping off the well trodden path. Good luck :)

> I hope you'll be able to solve any remaining issues with it 
> (mplayer with PA is something I simply cannot live with.)

I've used mplayer with PA for about two or three years. There have been
a couple bugs along the way but none that are not solved AFAIK. Works
great here.



Colin Guthrie

Day Job:
  Tribalogic Limited []
Open Source:
  Mandriva Linux Contributor []
  PulseAudio Hacker []
  Trac Hacker []

More information about the kde-multimedia mailing list