Android MediaRecorder 小结

调用顺序

MediaRecorder.java
  +- android_media_MediaRecorder.cpp
       +- MediaRecorder.cpp
            +- MediaPlayerService.cpp
                 +- MediaRecorderClient.cpp
                      +- StagefrightRecorder.cpp

重要的类

* MediaWriter
    +- MPEG4Writer
* MediaSource
    +- CameraSource

数据流向

             Camera
               |
               | CameraListener#postDataTimestamp(raw frame)
               |
              \ /
   CameraSource(MediaSource)
               |
               | read(raw frame)
               |
              \ /
 OMXCodec Encoder(MediaSource)
               |
               | read(encoded frame)
               |
              \ /
    MPEG4Writer(MediaWriter) 
               |
               | mux
               |
              \ /
            MP4 File

CameraSource 帧队列

    List<sp<IMemory> > mFrames;   // 帧
    List<int64_t> mFrameTimes;    // 帖的相对时间戳

• read 消费者线程
• dataCallbackTimestamp 生产者线程