how to order ALSAMixers?

Submitted by slackhead on Sat, 2020-10-03 01:46

Forums:

MOC version: 
2.6-alpha2

I suspect that this may be a hardware problem, since I am using an output that has no volume control, and I had to add a softvol for it in ~/.asoundrc.

First off, I normally use jack for music, but I also have voicemail files to play which are 8 kHz wav, and sound much clearer using alsa rather than jack.

The problem I'm finding is trying to work out the correct ALSAMixers to use.

I have "ALSADevice = default" and my ~/.asoundrc has default routed
to a Loopback, and then to jack and out through S/PDIF digital to the amp and speakers.

The main mixer is named Softvol0, which is the one I added to the digital output in ~/.asoundrc.

What I would like is to use that as a second mixer and have an extra
software mixer for the first/main mixer. I can get one named 'Soft' in moc using:

ALSAMixer1 = PCM
ALSAMixer2 = Softvol0

But, however I order those, Softvol0 is *always* the first one
showing, and I must press 'x' twice to get to 'Soft' which is a bit
strange. I don't want to use Softvol0 as the main mixer in moc because it controls all the sound output level.

'Master' controls the analogue speaker outputs, and so has no effect on S/PDIF at all.

Extra info:

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: D2X [Xonar D2X], device 0: Multichannel [Multichannel]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 0: D2X [Xonar D2X], device 1: Digital [Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 9: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 9: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
Subdevices: 1/1
Subdevice #0: subdevice #0

Some relevant bits of ~/.asoundrc:

pcm.!default {
type plug
slave.pcm "asoftvol"
}

pcm.asoftvol {
type softvol
slave.pcm "amix"
control.name "OUT"
min_dB -51.0
max_dB 15.0
}

pcm.amix {
type dmix
ipc_key 196101
slave.pcm "hw:Loopback"
}

pcm.cloop {
type hw
card Loopback
device 1
subdevice 0
format S16_LE
}

pcm.digi0 {
type softvol
min_dB -51.0
control { name "Softvol0 Playback Volume" card 0 }
slave.pcm "plug:equal"
# slave.pcm "hw:0,0"
}

Anyone have any ideas how to make the 'Soft' volume the first/main mixer in moc, and have Softvol0 as the secondary?

tomaszg

Sat, 2020-10-03 02:19

You can't without modifying MOC source code. However the change itself is very trivial. If I remember correctly, you need to change the line in audio.c
static int current_mixer = 0;
to
static int current_mixer = 2;
I didn't check it now.