[LAD] Should LV2 Activate() clear MIDI CC parameters?

Albert Graef Dr.Graef at t-online.de
Wed May 30 08:20:57 UTC 2012

On 05/29/2012 07:57 PM, David Robillard wrote:
> tl;dr: The state that needs to be reset is state that depends on a
> continuous stream of audio.  Midi controllers and such do not cause
> problems if they persist across audio gaps, and are not what was being
> referred to here.

Exactly. In the case of an instrument plugin, that might mean, e.g.,
that the allocated voices and the pitch bends are reset, but usually not
the controllers. Incidentally, that's exactly how I implemented those
callbacks in faust-lv2, and it works nicely with Qtractor at least.

Paul, you said that Ardour doesn't do activate()/deactivate() with
effect plugins. Is that the same with instrument plugins? Then the
scheme I used in faust-lv2 probably doesn't fare that well with Ardour3,
unless it takes care of resetting the plugin in some other way.

Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr.Graef at t-online.de, ag at muwiinfa.geschichte.uni-mainz.de
WWW:    http://www.musikinformatik.uni-mainz.de/ag

More information about the Linux-audio-dev mailing list