y音频学习
http://blog.csdn.net/xuesen_lin/article/details/8787779
http://www.alloyteam.com/2013/12/android-audio-module-learning-summary/
https://github.com/bboyfeiyu/android-tech-frontier/blob/master/issue-9/Android%2010ms%E9%97%AE%E9%A2%98%EF%BC%9A%E5%85%B3%E4%BA%8EAndroid%E9%9F%B3%E9%A2%91%E8%B7%AF%E5%BE%84%E5%BB%B6%E8%BF%9F%E7%9A%84%E8%A7%A3%E9%87%8A.md
http://www.cnblogs.com/linucos/archive/2013/03/26/2982999.html
http://www.yrom.net/blog/2013/11/08/audio-focus/
http://blog.csdn.net/eilianlau/article/details/7184287