I'm ok with regex, but the ffmpeg manpage, it scares me...

Ffmpeg was designed to be unusable if it falls into enemy hands.

I am perfectly at home with regexp, but ffmpeg, magick, and jq are still on the list to master.

Regex is only difficult because it's complicated, the primitives are all sensibly arranged and predictable. FFmpeg is layers of dark magic where the primitives are often inscrutable before you compose them.