VST effect plugins

[Be]

The SDK for version 3 of the popular VST plugin format is available under the GNU GPL v3:
https://github.com/steinbergmedia/vst3sdk/blob/master/LICENSE.txt
Mixxx is currently licensed under the GNU GPL v2 or later, so as far as I understand (and IANAL), we could legally implement VST3 support if we distribute Mixxx as a whole under the GNU GPL v3. I think old code by itself would remain under the GPL v2 or later. Practically I don't think there would be any difference for us except maybe adding some clarification to the LICENSE file. We should consult with a lawyer before doing this to be clear, which is another good reason to join Software Freedom Conservancy.

Related: LV2 plugin support (Bug #1530238)

[Be (be.ing)]

VST API documentation is available at https://github.com/steinbergmedia/vst3_doc . Inconveniently it is not hosted online anywhere as far as I can tell, so to read it you need to download that Git repository and view it locally. From a quick glance at the documentation, VST seems much more complex than LV2 and lilv.

[Daniel Schürmann (daschuer)]

Are there actually many VST3 plug-ins out there? VST2 and VST3 are not compatible.
Is there a killer plug-in, that Mixxx needs in VST2 or VST3?

[Be (be.ing)]

I'm not sure, but I think many VST plugins are distributed in both VST2 and VST3 versions.

I have removed this from the 2.3 milestone because I have no intention to work on this feature myself. If anyone else wants to commit to implementing this, please assign yourself to this issue and target it to a milestone.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9019