[LAD] LADSPA plugins in ardour

[David Robillard]

On Sun, 2009-08-09 at 13:52 -0400, Paul Davis wrote:
> On Sun, Aug 9, 2009 at 11:22 AM, Fons Adriaensen<fons at kokkinizita.net> wrote:
> > Hello all,
> 
> wrong maiing list, really. but continuing on ...
> 
> > I have an ardour mixer strip with 4 input and 2 outputs,
> > and insert (post-fader) a plugin which has 4 inputs (A,B,C,D)
> > and two outputs (X,Y).
> >
> > The signals at the output of the strip seem to be
> > X + C + D and Y + C + D instead of X and Y.
> >
> > Is this 'documented behaviour', and if yes what
> > purpose does it serve ?
> 
> its certainly not documented, but not much is. it doesn't serve any
> purpose other than being one of the several approaches one could take
> with this somewhat unusual (but certainly not wrong) i/o
> configuration. basically, ardour has the concept of "data streams"
> within the signal processing route. imagine the situation *without*
> the plugin for a moment: what happens to the "extra" data streams C &
> D that don't obviously map to the outputs? executive decision: add
> them to the outputs (and do it badly, by adding C *and* D to both
> outputs, just for good measure). add the plugin to the situation ....
> presumably ardour should know that there are now really just two data
> streams post-plugin and that nothing needs to be done. but it appears
> that it doesn't discover this, and this may be intentional but more
> likely is just a bug.

This behaviour will be manually configurable (and smarter by default) in
3.0, FWIW.  Particularly with (LV2) plugins that give more useful
information about what ports represent.

Cheers,

-dr