live555 如何设置时间戳

rtsp客户端发送播放请求后,rtsp服务器调用流程如下

h264 video rtsp

1.ServerMediaSubsession::startStream -> OnDemandServerMediaSubsession::startStream

2.startStream -> StreamState::startPlaying

3.MediaSink::startPlaying

4.MediaSink::continuePlaying->MultiFramedRTPSink::continuePlaying

5.MultiFramedRTPSink::buildAndSendPacket

6.MultiFramedRTPSink::packFrame()  fSource->getNextFrame fSource type is H264FUAFragmenter

7.FramedSource::getNextFrame

8.FramedSource::doGetNextFrame ->H264FUAFragmenter::doGetNextFrame  ->  fInputSource->getNextFrame fInputSource type is H264VideoStreamFramer

9.H264VideoStreamFramer::getNextFrame -> MPEGVideoStreamFramer::doGetNextFrame

10.MPEGVideoStreamFramer::continueReadProcessing -> fParser->parse()   fParser type is H264VideoStreamParser

11.H264VideoStreamParser::parse()   -> ByteStreamFileSource::doGetNextFrame -> ByteStreamFileSource::doReadFromFile

时间戳生成流程

1.MultiFramedRTPSink::buildAndSendPacket 中组建rtp包头时，获取时间戳的位置fTimestampPosition，然后等待获取数据与时间戳后写入

2.MultiFramedRTPSink::afterGettingFrame1 ->H264VideoRTPSink::doSpecialFrameHandling->MultiFramedRTPSink::setTimestamp 将时间戳写入到rtp包中

3.H264VideoStreamParser::parse 中调用H264VideoStreamFramer::setPresentationTime { fPresentationTime = fNextPresentationTime; } 此fPresentationTime最终将传到步骤2中

4.fNextPresentationTime 初始化由构造函数获取当前时间戳 ，后续在H264VideoStreamParser::parse 当thisNALUnitEndsAccessUnit=TRUE后，根据帧率计算帧duration，然后计算下一帧的时间戳

    if (thisNALUnitEndsAccessUnit) {
#ifdef DEBUG
      fprintf(stderr, "*****This NAL unit ends the current access unit*****\n");
#endif
      usingSource()->fPictureEndMarker = True;
      ++usingSource()->fPictureCount;

      // Note that the presentation time for the next NAL unit will be different:
      struct timeval& nextPT = usingSource()->fNextPresentationTime; // alias
      nextPT = usingSource()->fPresentationTime;

	  
	// printf("*************time:%d_%d^^^^%.5f\n",usingSource()->fPresentationTime.tv_sec,usingSource()->fPresentationTime.tv_usec,usingSource()->fFrameRate);//sun

      double nextFraction = nextPT.tv_usec/1000000.0 + 1/usingSource()->fFrameRate;
      unsigned nextSecsIncrement = (long)nextFraction;
      nextPT.tv_sec += (long)nextSecsIncrement;
      nextPT.tv_usec = (long)((nextFraction - nextSecsIncrement)*1000000);
    }

void H264FramedLiveSource::doGetNextFrame()
{
	//用光该帧的所有数据，再去用下一帧，如果当前没有数据，则framesize 设置成 0

	fDurationInMicroseconds = 0;
	fFrameSize = 0;
	fNumTruncatedBytes = 0;
	{
		if (m_BufferCtrl.GetBufferSize() <=0)
		{

			{
				FRAME_INFO *pFrameInfo = NULL;
				m_pPullDataObj->GetVideoFrame(pFrameInfo);
				
				if (pFrameInfo != NULL)
				{
					
					if (fPresentationTime.tv_sec == 0 && fPresentationTime.tv_usec == 0) {
						// This is the first frame, so use the current time:
						//m_pPullDataObj->SetCurVideoStamp(pFrameInfo->dts);
						fDurationInMicroseconds = 0;
						gettimeofday(&fPresentationTime, NULL);
						m_startPts = pFrameInfo->dts;
						m_startTmpPts = pFrameInfo->dts;
						gettimeofday(&fTempTime,NULL);

						//{
						//	char buf[100] = {0};
						//	sprintf(buf,"Init video:==================%d:%d:frame pts:%d\n",fPresentationTime.tv_sec,fPresentationTime.tv_usec/1000,pFrameInfo->pts);
						//	OutputDebugStringA(buf);
						//}
					} else {
						// Increment by the play time of the previous frame:

						static int nCount = 0;
 						unsigned long long uSeconds = (pFrameInfo->dts-m_startTmpPts)*1000;
						printf("==============video frame:pts %lld\n",pFrameInfo->dts);
						//printf("===============video pts:%lld    ,   %lld     ,%lld\n",uSeconds,pFrameInfo->pts,m_startTmpPts);
						fTempTime.tv_sec += (fTempTime.tv_usec+uSeconds)/1000000;
						fTempTime.tv_usec =  (fTempTime.tv_usec+uSeconds)%1000000;
						
						fPresentationTime = fTempTime;
						printf("============time:%lld_%lld\n", fPresentationTime.tv_sec, fPresentationTime.tv_usec);

					//	m_pPullDataObj->SetCurVideoStamp(pFrameInfo->dts);
						fDurationInMicroseconds = (pFrameInfo->dts - m_startPts)*1000;
					//	m_startPts = pFrameInfo->dts;
					m_startTmpPts = pFrameInfo->dts;

// 						long sec = pFrameInfo->dts*1000/1000000 ;
// 						long usec = pFrameInfo->dts*1000%1000000;
// 
// 						fPresentationTime.tv_sec = fTempTime.tv_sec + sec;
			//			unsigned uSeconds = fPresentationTime.tv_usec + fDurationInMicroseconds;
			//			fPresentationTime.tv_sec += uSeconds/1000000;
			//			fPresentationTime.tv_usec = uSeconds%1000000;

						printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<time:%d_%d,0x%x\n",fPresentationTime.tv_sec,fPresentationTime.tv_usec,this);//sun

						//{
						//	char buf[100] = {0};
						//	sprintf(buf,"video:==================%d:%d:frame pts:%d",fPresentationTime.tv_sec,fPresentationTime.tv_usec/1000,pFrameInfo->pts);
						//	OutputDebugStringA(buf);
						//}

					}

					m_BufferCtrl.PullBuffer((char*)pFrameInfo->pBuffer,pFrameInfo->dwSize);
					
					delete pFrameInfo;
					pFrameInfo = NULL;
				}
				else
				{
					int iiii = 0;
				}

			}

		}

	}

	


	{
		
		int nBufferSize = m_BufferCtrl.GetBufferSize();
		
		{

			if (nBufferSize >0 && nBufferSize <= fMaxSize)
			{
				int nsize = -1;
				m_BufferCtrl.PopBufferAll(nsize,(char* &)fTo);
				fFrameSize = nsize;

			}
			else if (nBufferSize > fMaxSize)
			{
				m_BufferCtrl.PopBuffer(fMaxSize,(char* &)fTo);
				fFrameSize = fMaxSize;
			//	fNumTruncatedBytes = nBufferSize - fMaxSize; 

				OutputDebugStringA("\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n");

			}
			else
			{
				int iii = 0;
			}
		}



	}

	{
		char buf[100] = {0};
		sprintf(buf,"video:==================duration:%d\n",fDurationInMicroseconds);
		OutputDebugStringA(buf);
	}


	//fDurationInMicroseconds = 40000;

	//m_pPullDataObj->SysncFrame();




	nextTask() = envir().taskScheduler().scheduleDelayedTask( 0,
		(TaskFunc*)FramedSource::afterGetting, this);//表示延迟0秒后再执行 afterGetting 函数


}