[LAD] LV2 plugin host MIDI channel number detection

[Paul Davis]

On Tue, Mar 15, 2016 at 9:26 PM, Yassin Philip <philcm at gnu.org> wrote:

> Hello!
>
> Some LV2 plugins seem to now the MIDI channel # of the track on which they
> are inserted, and some don't.
>

There is no such concept in LV2.

The idea of a track "having" "a" MIDI channel is entirely host specific and
isn't covered by any part of LV2 that i'm aware of.


> If I had to guess I'd say that nobody knows, only some plugins can receive
> data from several MIDI channels, and some only work with one, so they never
> mistake ; Am I right?
>

As with all other plugin APIs, yes.


>
> Last year I made a GUI around so-404 to learn about LV2 (and C, C++, DSP
> code, etc. :)) ; And it has the same problem, just sightly different:
> Worse: It starts numbering at 0, so if it's inserted on a track w/ MIDI
> #4, you have to select 3
> Better: It remembers said channel # on session reload (ZynAddSubFx
> doesn't. Yoshimi does)
>

MIDI channel numbering has always been a problem. Ardour has an option so
that the user can decide if MIDI channels start at zero or 1.


>
> Can somebody point me towards the light? I'd like my plugin to only listen
> to one channel: The one of the host track it's inserted into.
>

Given that there is no such thing, there's nothing you can do inside a
plugin to make it do this precise thing. You could make it listen to just
one MIDI channel, but that's not the same thing.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxaudio.org/pipermail/linux-audio-dev/attachments/20160315/6925e744/attachment.html>