I'm probably biased, but I particularly enjoyed going through mpv - https://github.com/mpv-player/mpv https://github.com/mpv-player/mpv I always found much of

I'm probably biased, but I particularly enjoyed going through mpv - https://github.com/mpv-player/mpv https://github.com/mpv-player/mpv I always found much of the FFmpeg API very unintuitive and much of what I now know about it I learned from reading through mpv. Hardware accelerated encode/decode, etc.