nostr:npub1azuxc0qs76rh2lz06r8pkpv45z7z7u5gplp8zlrhvg0aehcqp4vq7xyznj I would think there's already a FFmpeg pipeline that would probably do this.

Simulating CRT Monitors with FFmpeg

https://int10h.org/blog/2021/01/simulating-crt-monitors-ffmpeg-pt-1-color/

How to Add Subtitles to a Video File Using FFmpeg

https://www.bannerbear.com/blog/how-to-add-subtitles-to-a-video-file-using-ffmpeg/