On Tue, 13 Nov 2018 15:23:53 +0100, Guillermo Rodriguez Garcia wrote:

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)

It's mostly a historical reason.

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

Sure. You'd need to fix some more codes, not only removing the negative min_dB check, though.

thanks,

Takashi