https://www.jianshu.com/p/eaf0769da8af
http://blog.chinaunix.net/uid-11344913-id-5750194.html
http://www.cnblogs.com/yongfengnice/p/7156952.html
4.FFMPEG常用命令持續更新
https://www.jianshu.com/p/6a3a9946baf5?utm_campaign=maleskine&utm_content=note&utm_medium=seo_notes&utm_source=recommendation