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/
[0] https://link.springer.com/article/10.1007/s11214-020-00765-9
That being said, if you put down a pie chart of media frameworks (especially for transcoding or muxing), ffmpeg would have a significant share of that pie.