[alsa-devel] Mixer volume/decibel mapping

[Raymond Yau]

2010/5/25 Clemens Ladisch <clemens at ladisch.de>

> Raymond Yau wrote:
> > 2010/5/21 Clemens Ladisch <clemens at ladisch.de>
>
>
> > > 0 == -infinity dB, full scale == 0 dB, and the mapping between mixer
> > > control values and corresponding dB values it _not_ linear.
> > >
>

20 log10 rule

This mean than 0.5 == -6 dB ,  0.25 == -12 dB , 0.124 == -24dB . 0.625 ==
-48dB

I have doubt why PA is at 15% when the volume control of HDA is -48dB