This is a fantastic idea! I forked [1] projectM a while back to work on a few modifications such as screen and audio recording (by saving raw framebuffers) and being able to select the active preset remotely from a web interface so I became somewhat familiar with the way projectm handles A/V input/output.
I just took a look at ffmpeg’s video filter interface and it looks like linking the two could be doable!
This feels like a much more elegant solution for recording frame-perfect captures so thank you!
I’ll definitely be looking more into it.