Ask HN: How to generate flipbook-style animations from video?

I’ve been seeing a lot of hand-drawn flipbook animations on YouTube/TikTok. For example:

https://www.youtube.com/shorts/Ub_ZmzOrh5g

The creators say they spend 3-5 days drawing this. How do I generate this animation say in Python? Any recommended models, libraries, or workflows?

I am thinking ffmpeg to extract images -> pose estimation -> Line art -> Assemble into Video