[linux-audio-dev] Mixer controls

Hi,

I am an ALSA developer. I was hoping that someone on this list would
have experience with professional mixing desks.
I would like to duplicate the behavior of professional mixing desks in
the alsa mixer controls.

I am only interested in gain control at this point.
There are effectively two separate but linked controls for each gain
control.
a) Mute control
b) Gain control in dB.

If I have a gain control that starts at 0 dB, with each step down by 1
dB until -40dB. With DSPs, it is very easy to add the next step down as
being the mute level. E.g. Sample * gain_multiplier where for the mute
level, gain_multiplier = 0.0, thus resulting is a zero sample output.

My question is really what should I do when the gain_multiplier is 0.0

Do I:
a) Limit the range of the gain control to 0dB to -40 dB and have a
separate Mute control.
b) When the gain control has a gain_multiplier of 0.0, automatically
activate the Mute control.
c) Some other method.

Thank you

James
Received on Sun Nov 6 16:15:05 2005