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

[Tom Gundersen]

On Sun, Aug 12, 2012 at 5:01 PM, Fons Adriaensen <fons at linuxaudio.org> wrote:
> If you have apps A, B, C with volumes a, b, c you can always
> set the HW gain to unity gain (0dB), and send
>
>   s = a * A + b * B + c * C         (1)
>
> to the soundcard. What would be the advantage of doing what
> PA does, which is
>
> * m = maximum of a, b, c)
> * Set the master to m,
> * send
>
>   s = a/m * A + b/m * B + c/m * C    (2)

Take a=0.00001 (or some other sufficiently small number), b=2*a and
c=3*a. You then risk that with (1) you have s=0 due to rounding
errors, whilst with (2) s>0.

How big a problem this is in practice, I don't know. I'm a
mathematician, and not a sound engineer.

-t