am 187b196e: Merge changes Ic51e92e9,Ie808aa82,I74f5f4a1

* commit '187b196e48ed6ea655c7a0e48908d92d670627a8':
  stagefright: add SoftAVCEnc using libavc
  stagefright: add SoftAVCDec using libavc
  stagefright: add SoftMPEG2 decoder using libmpeg2