LV2, CC, and undo points

elcalen · 05-09-2022, 07:16 AM

Not entirely sure if this is an issue with Reaper or the plugin in question, but I was working on a project with the setBfree tonewheel organ LV2 plugin from x42 and I noticed I was getting a lot of "Edit FX parameter" undo events for the plugin, even though I wasn't touching any of the controls. setBfree can use CC messages to control various parameters, like (perhaps most usefully) the rotary speed control, and I discovered that the undo points were caused by these CC events changing the parameter during playback. Which surely shouldn't be the case, right?

I'm aware that for VSTs there's an option for minimal undo states, but apparently these compatibility options aren't available for LV2. No idea if that setting would be relevant if it did exist...

(This is with Reaper 6.57, on Linux.)

Justin · 05-09-2022, 06:40 PM

ah thanks, looking into this one now. The problem is that the plug-in sends notification that its state has changed, but there's no way for us to know whether it changed from a tweak of the UI or if it came from automation.

We'll add a per-plugin compatibility option to ignore state-change notifications (either completely, or just when the UI is closed). Not a perfect solution but helpful...

elcalen · 05-10-2022, 04:58 AM

Quote:

Originally Posted by Justin

We'll add a per-plugin compatibility option to ignore state-change notifications (either completely, or just when the UI is closed). Not a perfect solution but helpful...

Yeah, that would probably be a good enough work-around for my case. Thanks!

Justin · 05-10-2022, 05:50 AM

ah looks like we can have a setting which is “ignore state change when sending midi CC”… only time you’d miss it is if you tweak the UI simultaneously as sending CCs, it might treat it as a CC-only change…

Justin · 05-11-2022, 02:35 PM

The latest +dev build has this, if you want to test!

elcalen · 05-12-2022, 06:37 AM

The ignore when sending CC messages option at least would appear to be working, based on a very quick test. (Didn't try the other options, since I don't really have a need for them currently.) Assuming there are no unforeseen complications, this ought to be a good solution to my issue. Thanks!

To be fair, setBfree is kind of a weird plugin to begin with. It apparently doesn't expose any parameters for automation, but it does let you change various parameters via CC. Which was kinda confusing at first... It is, however, a totally free B3 emulation with some pretty robust features, so I'm glad I can use it in Reaper!