from http://www.roman10.net/how-to-build-ffmpeg-with-ndk-r9/ http://blog.naver.com/PostView.nhn?blogId=thesims1004&logNo=50184047966 http://kimdata.cafe24.com/wp/2014/02/04/ffmpeg-라이브러리를-이용하여-안드로이드-동영상-플레이/