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

[Raymond Yau]

2010/2/19 Lennart Poettering <mznyfn at 0pointer.de>

> On Thu, 18.02.10 14:15, Raymond Yau (superquad.vortex2 at gmail.com) wrote:
>
> > 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 ?
>
> Depends on the UI program. gnome-volume-control currently only puts a
> marker at the ALSA 0dB point, but not a second one where software amp
> starts.
>

For example , your program dbmeasure.c generate a full amplitude sine wave ,
the sine wave will be clipped for any software gain by pulseaudio , any
hardware att. by DAC cannot change the clipped sine wave