How to render big STR videos while keeping file size low

[Junior Jr.]

I've been messing around with the Movie Converter tool in the PsyQ SDK yesterday to see if I can render 5 minute videos without taking huge space (approx. 80MB when normally using uncompressed AVI). So far I tried converting MP4 videos into WEBMs because they can be condensed to as little as 3MB but when I use ffmpeg it bumps the video up to over 200MB!
Seeing as MC32 only takes uncompressed AVIs, I'm trying to find other possibilities to get more video into space that's less than 100MB.

Watching this really helpful video by Jon Burton about Sonic 3D Blast's intro inspired me to find other methods of adding big videos with little file size. This question about converting 1,000 PNG images into an AVI on Super User gave me an idea of trying to make a .GIF of a 5-minute video or splitting the video into individual frames and then make FFmpeg convert them all into a raw video, but what if each frame was dithered so the size on each frame was condensed and it tricked FFmpeg into exporting the same 5 or 10 minute video but without taking up a huge chunk of MBs?

I'm only testing the waters here, so I could be right or wrong, but I'm willing to see if it's possible to find other means of rendering big videos without eating up the disc.