How to feed MilkDrop music visualizations?

(MilkDrop3, projectm-visualizer/presets-cream-of-the-crop, westurner/vizscan for photosensitive epilepsy)

mapmapteam/mapmap does open source multi-projector mapping. How to integrate e.g. mapmap?

BespokeSynth is a C++ and JUCE based patch bay software modular synth with a "node-based UI" and VST3, LV2, AudioUnit audio plugin support. How to feed BespokeSynth audio and possibly someday video? Pipewire and e.g. Helvum?