`sndio_server` & `volume` variables are not actually used

[morgant]

It appears that the $sndio_server variable is not actually used. I think it should be used in $MON_IN, though it appears that using snd/mon is roughly equivalent. That said, in my testing, using snd/mon instead of snd/${sndio_server}.mon will not fail if the mon sub-device doesn't exist on the server device and will silently result is no audio (no pun intended). However, using snd/${sndio_server} will result in an error if the mon` sub-device doesn't exist:

[sndio @ 0x15d51a56800] Could not open sndio device
snd/0.mon: Input/output error

I think the error would be preferable if one is trying to record a monitor mix and haven't correctly configured sndiod(8).

UPDATE: It appears that sndiod(8) sub-device naming has changed sometime since OpenBSD 7.5 (see 7.5's sndiod(8) vs 7.6's sndiod(8) manual pages), so a monitor sub-device would be accessed as snd/mon instead of snd/0.mon. At least, the manual pages changed, so I need to re-research & test which method is correct (or are both still valid?)

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On a related note, I noticed that the "monitor only" recording doesn't utilize either the $volume_mon (as specified with -vmon <volume>) or the volume variable, so you can't control the volume for a monitor-only stream.

Furthermore, the $volume variable is actually not used anywhere. I'd suggest dropping the $volume variable (specified with -v <volume>) and using $volume_mon in monitor-only recordings.