ffmpeg

https://linjie.org/2015/08/06/amr%E6%A0%BC%E5%BC%8F%E8%BD%ACmp3%E6%A0%BC%E5%BC%8F-%E5%AE%8C%E7%BE%8E%E8%A7%A3%E5%86%B3Linux%E4%B8%8B%E8%BD%AC%E6%8D%A20K%E9%97%AE%E9%A2%98/

 

http://blog.csdn.net/zkn_cs_dn_2013/article/details/52639972

http://www.cnblogs.com/taosim/articles/3345303.html