[LAU] LV2 plugin to control alsa?

Len Ovens len at ovenwerks.net
Sat Mar 21 05:14:53 UTC 2015

This would not be portable across os... and require a config file. I am 
wondering if it is possible.

I am thinking it would be nice to have an lv2 alsa trimpot. The idea is 
that it would not affect the audio passing through, but provide a control 
that varies the level of an alsa control. This is so a mixer strip that 
was composed of plugins would be able to also control the alsa preamp 
level if it was available. I realize figuring out which channel goes to 
which strip at any one time (the same input channel might be routed to a 
number of channels at the same time) would be _difficult_. Knowing which 
control changes the level one wants might be hard to automate too. The 
user interface would require the ability for the user to set it (them). If 
there was more than one for the same control they would have to track as 
well (alsa mixers seem to do this already though).

The easy way to do this would be to throw away incoming audio and select 
our own. Some sort of middleware that gave a common interface for all AIs 
would make this much easier too. Mudita24 has MIDI control for this... but 
alas the midi control does not extend to the pre levels (ADC levels) where 
it would be most useful (or at least moving these controls outputs no midi 
the way the multimix controls do).

So far as I know, nobody does this, even in OSX/windows land 
though of course it is common on both analog and digital mixboards even 
when the pre is at the other end of a snake or on a foreign interface.

Len Ovens

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