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

[Fons Adriaensen]

On Sun, Aug 12, 2012 at 07:38:58PM +0200, "Jérôme M. Berger" wrote:

> 	Actually, that's one point where PA is right (even though it's
> wrong on a lot of other points): doing it like (2) avoids amplifying
> the quantification noise if the sound card applies the master gain
> in analog (or uses higher bit depths internally before the DACs as
> some do).

True, if the master is after the DAC, but even then irrelevant. 
Quantisation noise for a typical 20-bit (or even 16-bit) DA is
low enough so it doesn't matter. See previous post.

> 	When cascading amplifiers, it is always better to put the highest
> possible gain on the first stages (always leaving enough headroom to
> avoid clipping/distortion) so that later stages will not amplify the
> noise from the first stages (or so that they will reduce it along
> with the signal). The only case when this rule does not hold is when
> doing digital processing in floating point (because then the
> quantification noise is defined as a proportion of the actual signal
> instead of its potential maximum).

Correct again. But there's not reason why a software mixer
shouldn't use floating point, or a fixed point format (e.g.
32 bit integers) that provides enough room above and below.
Please don't tell me that PA is using 16-bit for its internal
operations - that would really prove it's complete crap.

Ciao,

-- 
FA

A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)