Currently, mixerctl.conf(5) says
Most devices have a number of digital to analogue converters
(DACs), used for sound playback, and each DAC has a corresponding
output mixer. The mixers are labelled “mix” or “sel”.
That doesn't seem to be the case, at least not universaly
as the wording seems to imply. For example, this is
mixerctl output on a Thinkpad T400:
inputs.dac-0:1=222,222
inputs.dac-2:3=222,222
inputs.beep=0
record.adc-2:3_source=mic2
record.adc-2:3=219,219
record.adc-0:1_source=mic
record.adc-0:1=219,219
outputs.hp_source=dac-0:1
outputs.hp_boost=on
inputs.mic=189,189
outputs.mic_dir=input-vr80
outputs.spkr_source=dac-2:3
outputs.spkr_eapd=on
inputs.mic2=189,189
outputs.hp_sense=unplugged
outputs.mic_sense=unplugged
outputs.master=240,240
outputs.master.mute=off
outputs.master.slaves=
record.volume=240,240
record.volume.mute=off
record.volume.slaves=
record.enable=sysctl
Apparently, it has two DACS (for the speakers and the headphones).
The current wording might confuse the user into thinking he has
no output mixer, but the
inputs.dac-0:1=222,222
inputs.dac-2:3=222,222
do control the respective volumes,
while no "mix" or "sel" exists.
Similarly for recording via the two ADCs.
Jan
Index: mixerctl.conf.5
===================================================================
RCS file: /cvs/src/share/man/man5/mixerctl.conf.5,v
retrieving revision 1.10
diff -u -p -r1.10 mixerctl.conf.5
--- mixerctl.conf.5 21 Apr 2020 21:32:26 -0000 1.10
+++ mixerctl.conf.5 17 Oct 2020 15:31:23 -0000
@@ -66,10 +66,6 @@ TOSLink, RCA, or 1/8" mini stereo.
Most devices have a number of digital to analogue converters (DACs),
used for sound playback,
and each DAC has a corresponding output mixer.
-The mixers are labelled
-.Dq mix
-or
-.Dq sel .
Each DAC represents two channels of playback.
.Pp
Verify that playback works by playing an audio file
@@ -104,10 +100,6 @@ shows the number of channels available.
Most devices have a number of analogue to digital converters (ADCs),
used for recording sound,
and each ADC has a corresponding input mixer.
-The mixers are labelled
-.Dq mix
-or
-.Dq sel .
Each ADC represents two channels of recording.
.Pp
Connect line in on the audio card to an audio source,
