FR: CLAP plugin support

[dmt-hub]

Feature Description

Support for loading CLAP plugins into MiXXX would be very nice. ( https://cleveraudio.org/1-feature-overview/ )
With the option to have (per loaded plugin) - 8 macro controls which show as knobs inside mixxx fx lane - which you can link to 8 plugin parameters of choice.
I noticed Audio Unit support will be implemented soon? Having 8 macro controls per plugin for AU plugins would be very interesting too.

[fwcd]

Our existing plugin backends (AU and LV2) use the effect system, so I think it would make most sense to implement any new plugin formats in the same way. Basically the plugin has to expose a set of parameters which can then be controlled in the usual manner via the UI or from a controller. Support for effect GUIs could also be added after we merge #13888.

[dmt-hub]

@fwcd Yes that would be perfect. Thank you!
Can we already experiment with Audio Units inside mixxx or is that function not ready yet?

[fwcd]

Yes AU support is in 2.5, but without GUIs.

[dmt-hub]

@fwcd
I am using 2.5 beta and indeed i can load an AU, as there is no GUI yet it cannot be used atm? or is there a way to expose the plugin controls into the fx lane?

[fwcd]

Yes, you can control the plugin's parameters via the effect rack. GUI support is not merged yet.

[dmt-hub]

@fwcd How can i expose the parameters into the effect rack? i tried different AU plugins, and no parameters are shown.

[fwcd]

Try the builds in #13945 and #13887

[dmt-hub]

@fwcd Sorry for my question, but can i download these builds somewhere or do i need to build it myself?

[dmt-hub]

Tried building from source before but always got stopped on this issue:
after doing cmake ..

-- Found WrapAtomic: TRUE
CMake Error at CMakeLists.txt:2174 (find_package):
Could not find a package configuration file provided by "GTest" with any of
the following names:

GTestConfig.cmake
gtest-config.cmake

Add the installation prefix of "GTest" to CMAKE_PREFIX_PATH or set
"GTest_DIR" to a directory containing one of the above files. If "GTest"
provides a separate development package or SDK, be sure it has been
installed.

-- Configuring incomplete, errors occurred!

(trying to build on MacOS sonoma)

[fwcd]

You don't have to build from source, you can grab the GitHub Actions builds:

W.r.t building from source, you should look into setting up a vcpkg buildenv, which contains all dependencies (e.g. gtest).

[dmt-hub]

@fwcd Thanks for your patience and help, downloading now!

[dmt-hub]

@fwcd Yes, thats working out fine. Noticed only the first 8 parameters are exposed, i guess thats to be expected at this stage of the implementation?
Would be nice for future version of mixxx if there would be an option to choose which 8 parameters are exposed into the fx lane, so one can choose the most useful parameters to have in there.

[fwcd]

Out of curiosity, did #13945 already fix the issue of missing parameters for you or did you need the other PR with async initialization?

Agree that it would be nice to have a way of displaying more parameters or choosing a different subset, not sure if Mixxx already has something for that.

[dmt-hub]

@fwcd
Yes, 13945 fixed the parameters issue, just Aaltoverb is not showing its parameter names tho.
I noticed in this build the Retina scaling doesnt work as expected.

[dmt-hub]

My request was linked to this issue, with macro knobs one could assign 8 favorite parameters from a plugin to each macro knob, these 8 macro knobs would be shown in the fx lane.

[dmt-hub]

In this effects preference windows it could show all available parameters per plugin, lets say one can then place 8 checkboxes in front on the parameters that should be shown into the fx lane.. for example

[fwcd]

That might be worth filing a separate issue for, since it could probably be implemented generically for all effects.