[arch-general] OT: [arch-dev-public] polkit package upgrade patch

[Leonid Isaev]

On Sun, 12 Aug 2012 18:02:59 +0200
Tom Gundersen <teg at jklm.no> wrote:

> On Sun, Aug 12, 2012 at 5:27 PM, Fons Adriaensen <fons at linuxaudio.org> wrote:
> > On Sun, Aug 12, 2012 at 04:00:47PM +0200, Tom Gundersen wrote:
> >
> >> You have showed that it is unnecessary in one particular (very simple)
> >> case. However, you have not showed that it is unnecessary in all
> >> cases, so this is not really relevant (had we been talking about a
> >> human doing this, you'd have a point of course).
> >
> > I suspect that mathematical thinking is not your thing - no
> > problem. For otherwise it would be clear that the 'simple'
> > example I provided covers the general case.
> >
> > Let me try again. I write a PA-aware sound app X that
> >
> > * always sets its volume to 0 dB (max).
> > * always outputs silence (zero valued samples).
> >
> > As soon as that app runs, PA will set the master gain to
> > 0 dB and use software scaling on all other apps. Now there
> > are two possibilities:
> >
> > * Either everything is OK (it will be), and we have shown
> >   that you can always leave the master gain at 0 dB,
> >
> > * or everything is not OK, and we have shown that PA
> >   fails.
> 
> Your argument was clear (I'm ok with maths :) ). I was just pointing
> out that the case where the hardware can always be set to 0dB is not
> the interesting one.
> 
> You clearly want to avoid setting the hardware to >0dB if possible,

Correct me if I'm wrong but I don't think that's possible, because dB is
normalized to max power (in watts = intensity).

> but sometimes it is not possible (because you can't hear anything ;) )
> so you have to have an algorithm to do it in the best way. Imagine you
> have two streams (A) which needs no software nor hardware gain, had it
> been played alone, and (B) which forces the hardware gain to be >0dB
> (and (A) to be scaled down in sw). If (B) goes away you clearly want
> to set the hw volume back to 0 and (A) to stop being scaled in sw.
> 
> The second case, where the total gain should be <0dB, I would have
> thought intuitively that doing this purely in software (especially on
> very faint signals) would be less ideal than doing it in hw (you'd be
> throwing away the resolution, wouldn't you?), but I'll admit that I
> don't have the experience to talk about that with any authority.
> 
> -t



-- 
Leonid Isaev
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