[ardour-dev] ardour2 generic midi control surface feedback

[Ben Loftis]

> Feedback for the Generic MIDI control surface hasn't been working in
> ardour2. This patch makes it work. Made against revision 1220. It
> doesn't address the following:
>
> - sometimes motorised sliders on the control surface get 'sticky'. This
> happens when ardour tries to send feedback to the control surface, when
> it's the control surface that's generating the movement.  
>
>   

If the device is not touch sensitive, there's not much you can do about 
'stickiness' from within Ardour.  A properly touch-sensitive fader will 
disengage the motor when it is touched.  If the protocol allows, it 
should also send a "touch" command to Ardour.  This allows Ardour to 
start writing automation without actually moving the fader.

Devices with no touch circuit are not good for continuous automation, 
but may work for snapshot automation.... this is one of the cases where 
"you get what you pay for".

As "generic MIDI" does not have a touch parameter, it is heavily 
dependent on the device itself whether dynamic automation will be 
possible.  If implemented correctly, it should allow you to move it 
without getting 'sticky' and it may send the current fader value when 
touched, which would allow Ardour to start writing automation.

However there are several implementations of touch out there, depending 
on how much smarts are built into the device itself.  Ardour should 
allow each surface driver to implement their own version of touch sensing.

-Ben Loftis
http://www.harrisonconsoles.com