aac enc dec by fdk_aac
from: #https://github.com/mstorsjo/fdk-aac
https://blog.csdn.net/u013692429/article/details/99680818
解码: http://blog.chinaunix.net/uid-25272011-id-3491488.html 可以将aac 解码成pcm和wav格式
aac enc: ./aac_enc founders.wav out.aac fdk_aac aac编码时,已经自动添加ADTS.这7个字节在编码前面