提炼MP4相关接口和代码

src/Record/MP4Reader.h

@@ -35,6 +35,7 @@ public:
      * 意思是在文件流化结束之前或中断之前,MP4Reader对象是不会被销毁的(不管有没有被外部对象持有)
      */
     void startReadMP4();
+
 private:
     //MediaSourceEvent override
     bool seekTo(MediaSource &sender,uint32_t ui32Stamp) override;
@@ -45,15 +46,16 @@ private:
     uint32_t getCurrentStamp();
     void setCurrentStamp(uint32_t ui32Stamp);
     bool seekTo(uint32_t ui32Stamp);
+
 private:
-    recursive_mutex _mtx;
-    MultiMediaSourceMuxer::Ptr _mediaMuxer;
+    bool _have_video = false;
     uint32_t _seek_to;
+    recursive_mutex _mtx;
     Ticker _seek_ticker;
     Timer::Ptr _timer;
     EventPoller::Ptr _poller;
     MP4Demuxer::Ptr _demuxer;
-    bool _have_video = false;
+    MultiMediaSourceMuxer::Ptr _mediaMuxer;
 };
 
 } /* namespace mediakit */