[alsa-devel] using the softvol plugin with min_dB > 0

[Guillermo Rodriguez Garcia]

Hi all,

I have a board with a tlv320aic3106 codec and a digital mic. The
tlv320aic3106 does not support hardware gain for the digital mic, so I
am using the softvol plugin to provide this via software.

I would like to setup softvol so that it applies a gain in a range
that goes from approx +10dB to approx +40dB. The problem is that
softvol only accepts negative values for min_dB, i.e. assumes that you
*always* want to do attenuation, and that you might or might not want
to have gain (max_dB can be zero or negative).

Is there any reason for this, or is it just historical ? (I am aware
that the original softvol plugin only supported attenuation, and that
support for gain was added later)

Is it possible to setup softvol to accept a positive min_dB value ?

Best regards,

Guillermo Rodriguez Garcia
guille.rodriguez at gmail.com