[alsa-devel] Verifying mixer dB data/Invalid dB data from USB cards, especially Aureon 5.1 MkII

[Raymond Yau]

2010/2/18 Lennart Poettering <mznyfn at 0pointer.de>

> On Thu, 18.02.10 09:48, Raymond Yau (superquad.vortex2 at gmail.com) wrote:
>
> > From the viewpoint of user, they only care how easy to find the point
> which
> > is no software gain or software auttentation  since software gain lead to
> > clipping
>
> We decided to expose software amplification in the UI, since it is
> actually a much requested feature, and I have used myself a couple of
> times.
>
> The primary use case is when you play a DVD (which very often has
> audio normalized to a very low volume) on weak speakers, such as
> laptop speakers.
>
> Lennart
>
>
VLC media player has a slider from 0% to 300% , so the user are easily to
know  100% is the point which there is no software gain and no software
autentation

How did PA expose these software amplication in the UI so that ordinary user
can know that point ?

For the Mic Boost +20dB case , how PA handle this +20dB switch in the "Flat
Volume" model if you did not expost the Mic Boost switch to the user in the
mixer control ?

+20dB is quite significant in with the Capture Volume control