FFmpeg文档	http://ffmpeg.org/documentation.html
FFmpeg wiki	https://trac.ffmpeg.org
H.264视频编码指南	http://trac.ffmpeg.org/wiki/Encode/H.264
AAC音频编码指南	https://trac.ffmpeg.org/wiki/Encode/AAC
理解码率控制模式(x264, x265, vpx)	https://slhck.info/video/2017/03/01/rate-control.html
CRF指南(Constant Rate Factor in x264, x265 and libvpx)	https://slhck.info/video/2017/02/24/crf-guide.html
录屏	http://trac.ffmpeg.org/wiki/Capture/Desktop