[alsa-devel] wrong decibel data?

[Raymond Yau]

2010/5/28 Colin Guthrie <gmane at colin.guthr.ie>

> 'Twas brillig, and Colin Guthrie at 27/05/10 15:43 did gyre and gimble:
> > PA should play nice with the softvol plugin so I don't think this is the
> > bit that is at fault.
> >
> > I strongly suspect that the reason has already been correctly identified
> > a while ago, which is that this card considers -48dB silent where as PA
> > assumes this level is -200dB. I believe it was Raymond who pointed out
> > the -48dB level in the HDA spec before on this list.
> >
>

if  floating point 0.0 is -inf dB , and 1.0 is 0dB ,

0.5 is -6dB , 0.25 is -12 dB , 0.125 is -24dB and 0.0625 is -48dB

how can PA master volume control at 10~15% equivalent to HDA 's -48dB ?

Can you provide the pulseaudio log when you change the volume from 100% to
0% ?