plugdata-team
plugdata.vst3 Multichannel Support: Bug
It seems plugdata.vst3 and plugdata-fx.vst3 are only reporting they support 2 i/o channels to the host / DAW. Using a host that reports the i/o support of a plugin before loading it, it's clear plugdata is only reporting support for 1/1, 1/2, 2/1 and 2/2 support (mono and stereo fx inserts only) which is really just the default vst3 standard I think.
As plugdata.vst3 can actually accept upto 32/32 i/o I would expect the vst3 to be reporting that to the host, so that the host knows what to do with plugdata. At the moment it's a powerful multichannel .vst3 but only hosts that simply don't care will offer the straight 32/32 i/o support but there's far more DAWs that don't support this way of using plugins than do, so I think at plugdata.vst3 should be re-built and include it supports at minimum 1, 2, 4, 8, 16, 32 i/o configurations although simply reporting everything upto to 32/32 i/o would be optimal in order to support all users use cases.
e.g. here's a .vst3 that supports upto 8/8 io so it lists each track i/o configuration you can insert the plugin on.
I think the problem is that plugdata supports 16 stereo channels, instead of a single input with 32 channels. So it's a 16x2 configuration instead of 1x32.
Btw, what DAW are you using? I'll use the same one to make sure I can reproduce this issue.
Hey, I was trying to replicate something similar in Live 11 and what I noticed is that at least the host recognizes, both with vst3 and AU 8 stereo busses in input (but not 16, as I expected), and 16 stereo busses as outputs, but only AU is capable of routing them correctly. If using the vst3 a stereo signal sent to plugdata input bus 1 is correctly received in adc 1 and 2, but selecting any other input routing option (for ex buss 2 or 3 or 4 etc) will always be received on the same adc 3 and 4 only, no matter which buss it's sent to.
here a snapshot of the vt3 option. I selected buss 5 (which should be adc 9 10) but I still receive it on 3-4.
Using the AU selecting Buss 3 the signal is correctly routed to adc 5-6
On the other hand in Reaper everything works as expected also on VST3 and I can reach all 32 channels in input without issues. Dunno if it helps.
Reaper supports agnostic multichannel tracks and busses so will work with plugdata vst. As you're aware most DAWs expect the plugdata vst to tell it what mutlichannel format it requires the DAW to setup for it I believe.