live555 RTSP 服务器 是怎么获取视频帧的

[_山有木兮]

我刚接触live555不久 看源码有很多疑惑的地方。比如获取视频帧是怎么获取的，我没有看到像fopen fread这样的函数。
我就找BufferedPacket的成员变量fBuf 。

enqueue(&fBuf[fPacketStart + fOverflowDataOffset], fOverflowDataSize);[

是往fBuf 存数据吧？

void OutPacketBuffer::enqueue(unsigned char const* from, unsigned numBytes) {
  if (numBytes > totalBytesAvailable()) {
#ifdef DEBUG
    fprintf(stderr, "OutPacketBuffer::enqueue() warning: %d > %d\n", numBytes, totalBytesAvailable());
#endif
    numBytes = totalBytesAvailable();
  }

  if (curPtr() != from) memmove(curPtr(), from, numBytes);
  increment(numBytes);
}

[_山有木兮]

nobody nobody but you !

[rightorwrong]

是在取数据 跟程序看看

[_山有木兮]

我直接搜fread 还真有点效果。

FramedSource::getNextFrame ()

--》

****::doGetNextFrame()

--》

envir().taskScheduler().turnOnBackgroundReadHandling(fileno(fFid),
	       (TaskScheduler::BackgroundHandlerProc*)&fileReadableHandler, this);//原来添加到任务队列了

--》

source->doReadFromFile();

--》

fFrameSize = fread(fTo, 1, fMaxSize, fFid);//打开文件的句柄fFid

最终找到了doGetNextFrame， virtual void doGetNextFrame() = 0;是Framesource的虚函数被他的派生类继承了

[_山有木兮]

void FramedSource::getNextFrame(unsigned char* to, unsigned maxSize,//to就是doGetNextFrame();读取的视频数据
				afterGettingFunc* afterGettingFunc,
				void* afterGettingClientData,
				onCloseFunc* onCloseFunc,
				void* onCloseClientData) {
  // Make sure we're not already being read:
  if (fIsCurrentlyAwaitingData) {
    envir() << "FramedSource[" << this << "]::getNextFrame(): attempting to read more than once at the same time!\n";
    envir().internalError();
  }

  fTo = to;
  fMaxSize = maxSize;
  fNumTruncatedBytes = 0; // by default; could be changed by doGetNextFrame()
  fDurationInMicroseconds = 0; // by default; could be changed by doGetNextFrame()
  fAfterGettingFunc = afterGettingFunc;
  fAfterGettingClientData = afterGettingClientData;
  fOnCloseFunc = onCloseFunc;
  fOnCloseClientData = onCloseClientData;
  fIsCurrentlyAwaitingData = True;

  doGetNextFrame();//读数据就在这里面
}

[_山有木兮]