[Jack-Devel] How does --hwmon work?

[David Kastrup]

Ralf Mardorf <ralf.mardorf at alice-dsl.net> writes:

> On Fri, 05 May 2017 01:52:35 +0200, David Kastrup wrote:
>>"Chris Caudle" <chris at chriscaudle.org> writes:
>>> The hwmon option to jackd is just on/off, it doesn't give any way to
>>> control the gain of the connection, or the routing if there are
>>> multiple inputs and multiple outputs.  I think the jackd option never
>>> caught on because it was too limited to be useful.  
>>
>>Well, maybe.  In my ideal world, I'd tell Jack which channel I want to
>>map to which output with which gain, and if it can map this to
>>hardware, it will, and otherwise use software.  But of course this
>>would require putting this kind of thing into Jack API and
>>responsibility in the first place.  Jack can already connect in- and
>>outputs.  Just the gain is missing...
>
> Yes, jack already could do the I/O connections, but jack can't do the
> hardware routing, so not only a gain control is missing for what you
> want to get.

The typical sound card already has labelled ALSA controls for it (I
think the Firewire stack tends to moving to userspace applications for
mixer controls, but even those could be called from a Jack-controlled
thread).  The labels of those controls are just not associated with
standard meanings, but that could be rectified using asoundrc and its
ilk.  Basically the bits are there but not connected.

> The abilities of audio interfaces are very different. You seem to have
> an idea of what does fit good to your personal needs, but what you
> want to get seemingly is very unusual.

Controlling mixers other than manually?  If that were very unusual, Midi
control surfaces would not be as abundant as they are.

> The routing of hardware monitoring could be much too complex, that's
> why hdspmixer and/or mixing consoles are usually used.

Analog mixing consoles are on their way out.  Digital control surfaces
are everywhere and it's a bit strange that in the Linux DAW world they
cannot make it through to the hardware.

-- 
David Kastrup