[LAD] Lv2 port replication [was Re: the role of lv2 extensions]

[David Robillard]

On Thu, 2009-08-13 at 00:05 +0100, james morris wrote:
> On 12/8/2009, "David Robillard" <dave at drobilla.net> wrote:
> 
> >On Wed, 2009-08-12 at 23:39 +0100, james morris wrote:
> >> On 12/8/2009, "Steve Harris" <steve at plugin.org.uk> wrote:
> >>
> >> >On 12 Aug 2009, at 23:20, David Robillard wrote:
> >> >>
> >> >> Allow one group of ports to have either no replication, or the same
> >> >> replication count as another group of ports.  Obvious example being,
> >> >> controls tend to stick to 1, audio tends to get replicated, but we may
> >> >> want to replicate the controls to match audio.  So, a single plugin
> >> >> could do all of the above cases in a single instance, if the author
> >> >> wants to do it that way.
> >> >
> >> >That makes sense to me.
> >> >
> >>
> >> that's what i thought what i said implied [scratches head].
> >
> >.... I don't think "or ganging the control ports" really quite conveys
> >the idea entirely ;)
> 
> Don't be daft! I'll admit my LP filter example was less than concise.
> 
> >> >> Allow one group of ports to have either no replication, or the same
> >> >> replication count as another group of ports.  Obvious example being,
> 
> Which group of ports? The output group from the previous plugin in the
> chain? Why not just the number of channels? That's all that's needed
> for the simple case I'm talking about.

So the guy claiming he described the solution already is still working
on grasping the problem? :P </daft>

Other plugins are /way/ outside of scope.  What is "the number of
channels"?  Just some abstract parameter, we're designing a plugin API
here, not a modular synth's internals.  As described in the above quoted
email, the problem is sometimes you want the audio ports on plugin P
replicated and the control ports on plugin P singular, but other times
you want the control ports on plugin P replicated to match the audio
ports.  Anything to do with other plugins is well within "host's
problem" territory.

> Would it be worth having two extensions? One for complex examples useful
> for (modular) synthesis and voice polyphony,  and another for the simple
> cases such as the lp filter example?

In a word, no.  Same problem, and it seems a very simple solution can
handle the complex cases anyway.

Cheers,

-dr