I ran into the same problem with the using the libraries for the C based ffmpeg (libavcodec, etc). Even worst is trying to search for information only to wind up with hundreds of entries on how to use ffmpeg with the CLI with maybe 1-2 entries related to binding to the libraries grammatically.

Even ffmpeg's own documentation outside of what they generate for their API is rather sparse if you wish to do more than use it on the command line.