Usng libav*を読む

These can be useful for instance if you don't have access to a command line to run ffmpeg as an executable, or if you want to use just a small "part" of FFmpeg inside your own program, or if you want access to raw video frames in your program, etc. Also note that if you just need access to raw video frames, you could also write an audio or video filter and compile it along with FFmpeg and distribute that.

今の目的には合致してるんじゃないかな

まあ、ffmpegを使うこと、ないかもしれないけど・・・

いや、そんな内容なかったｗ