套装
android中使用更底层的api操作media，该套装原先用于组装MediaPlayer,目前开放给开发者，处理media,你值得拥有。
MediaCodec,
MediaExtractor,
MediaSync,
MediaMuxer,
MediaCrypto,
MediaDrm,
Image,
Surface,
AudioTrack
MediaCodec
added in api 16
对 audio 和 video 进行编码，解码，混合。(decode encode compress)
MediaExtractor
added in api 16
对音视频分路，通过media容器文件解析，转化为可以方便处理的packet
MediaMuxer
added in api 18
与MediaExtractor 相反，将media packet输出到media容器内。
目前仅支持mp4 和 webm? 输出格式，仅支持一个 audio track 一个video track
Currently supports mp4 or webm file as the output and at most one audio and/or one video elementary stream. MediaMuxer does not support muxing B-frames.
MediaCrypto
added in api 16
decode encrypted media data
MediaDrm
added in api 18
obtain keys for decrypting protected media streams
