I built a similar thing with the GPT-4 APIs a few weeks ago; thanks for the reminder that I must put it on GitHub at some point, as it's only about 30 lines of code.
https://www.youtube.com/watch?v=XX-ET_-onYU
But as you implied in your comment, it should be possible to do it quite well with any video by transcripting with whisper and then sending the text to gpt or another LLM to summarize.
From what I remember the Whisper API docs weren't too bad, but I didn't try actually implementing anything, so you could be right that they're underdetailed.
Does anyone have any additional insight into this problem?