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falkTX / Carla

Audio plugin host
https://kx.studio/carla
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Various Windows VSTs will not display their custom UIs #1451

Open mrz80 opened 3 years ago

mrz80 commented 3 years ago

This is a maddening issue that's seemed to have come and gone several times over various iterations of carla/wine/operating-system upgrades, back to 16.04 and the first version of Carla I tried running. I'm currently running:

Ubuntu Studio 20.04 with the backports repository active XFCE 4.14 Wine Staging 6.12 Carla 2.3.0 Yabridge 3.4.0

Carla will load a plugin just fine, audio and midi connections in jack work, and in most cases I get music out when I bang on the midi keyboard. But for some plugins, the Custom UI will only show a titlebar and a transparent window containing a static copy of whatever was on-screen behind it where it popped up. Sometimes, on some plugins, closing and reopening the custom UI several times will get the custom UI to display. The problem never happens with the Cherry Audio plugins, and usually doesn't happen with PG-8X and the U-He Tyrell N6. It happens consistently with DSK and Spitfire stuff. Looking at the carla logs shows no error messages that correlate to the problem; in most cases no messages were logged at all.

I was random-walking various google searches and came across what turned out to be the essential clue. Someone on a forum somewhere (lost the URL, of COURSE) mentioned having similar behavior trying to rune EVE Online under Wine. All his problems magically went away when he turned off the Compositor in Window Manager Tweaks. Sure enough! When I shut off the compositor, every plugin I tried worked exactly as expected, with a custom UI popping right up. Turn on the compositor, even with all the cool effects de-selected, and custom UIs started not displaying again.

So, it looks like something, either Carla or Wine, is getting into a fistfight with XFCE's display compositor. If anyone else has an issue with some plugin's UI not working, try shutting off the compositor in your window manager and see if that fixes things.

falkTX commented 3 years ago

It can just be a wine thing. I know versions after 6.4 were all lackluster in regards to plugin UI, even yabridge recommends to stick with v6.4 https://github.com/robbert-vdh/yabridge/#downgrading-wine

One thing worth trying is to export CARLA_DO_NOT_USE_JUCE_FOR_VST2 variable before starting carla (so that being on the same terminal) which will make carla use its native VST2 implementation instead of letting JUCE handle it. Obviously only works for VST2, not VST3s

mrz80 commented 3 years ago

Ok, I thought the "stay with 6.4" advice went away recently. 6.4 vs 6.12 really didn't make a difference with the behavior I was seeing, though.

Just for completeness' sake, I downgraded wine staging to 6.4. I tried firing up Carla with CARLA_DO_NOT_USE_JUCE_FOR_VST2 set. With display compositing enabled, I still get the broken-custom-UI behavior. Soon as I turn off the compositor, the UIs open up again. I don't really miss all the fun and fancy cool visual effects you get with the compositor, so I'm fine leaving it off. :)