I don't know a huge amount about video encoding, but I presume this is one of those libraries outlined in xkcd 2347[0]?
[0] - https://xkcd.com/2347/
replies(5):
[0] - https://xkcd.com/2347/
It also was originally authored by the same person who did lzexe, tcc, qemu, and the current leader for the large text compression benchmark.
Oh, and for most of the 2010's there was a fork due to interpersonal issues on the team.
This post talks about the situation back then: https://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html