海康威視實時預覽回調PS流用EasyRTMP向RTMP服務器推流中視頻數據處理的代碼

在上一篇方案《EasyRTMP結合海康HCNetSDK獲取海康攝像機H.264實時流並轉化成為RTMP直播推流（附源碼）》我們介紹了將海康安防攝像機進行互聯網直播的整體方案流程，其中有一個流程“數據處理與分析”我們當時沒有展開詳述，今天我們將海康HCNetSDK實時預覽回調接口數據處理的過程，尤其是在RealDataCallback中對AVData的處理過程：

		case NET_DVR_STREAMDATA:
			{
				BOOL inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
				while (!inData)
				{
					Sleep(10);
					inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
					OutputDebugString("PlayM4_InputData failed \n");	
				}	
				//PS流數據解析處理		
				{
					int nI = 0;
					int nCacheSize = 0;
					nI = m_mFrameCacheLenth[lRealHandle];

					//直接--提取H264數據
					BOOL bVideo = FALSE;
					BOOL bPatialData = FALSE;
					bPatialData = GetH246FromPS(pBuffer,dwBufSize, &m_pFrameCache[lRealHandle][nI].pCacheBuffer, 
						m_pFrameCache[lRealHandle][nI].nCacheBufLenth, bVideo);

					if (bVideo)
					{
						if (bPatialData)//部分包數據
						{
							//緩存數據
							m_pFrameCache[lRealHandle][nI].lTimeStamp = clock();
							m_mFrameCacheLenth[lRealHandle]++;
						} 
						else//包頭
						{
							int i = 0;
							if(m_mFrameCacheLenth[lRealHandle]>0)
							{
								long lH264DataLenth = m_mFrameCacheLenth[lRealHandle]*MAX_PACK_SIZE;
								BYTE* pH264Nal =  NULL;
								pH264Nal = new BYTE[lH264DataLenth];
								memset(pH264Nal, 0x00, lH264DataLenth);
								BYTE* pTempBuffer = pH264Nal;
								int nTempBufLenth = 0;

								//TRACE("m_mFrameCacheLenth==%d\r\n", pDemoDlg->m_mFrameCacheLenth);

								// 最大緩存數據個數設為pDemoDlg->m_mFrameCacheLenth，程序會過程中報錯，Why? [5/6/2014-13:19:51 Dingshuai]
								for (i=0; i</*MAX_FRAME_LENTH*/m_mFrameCacheLenth[lRealHandle]; i++)
								{
									if(m_pFrameCache[lRealHandle][i].pCacheBuffer!=NULL&&m_pFrameCache[lRealHandle][i].nCacheBufLenth>0)
									{
										// 										memcpy(pTempBuffer, m_pFrameCache[i].pCacheBuffer, m_pFrameCache[i].nCacheBufLenth);
										// 										pTempBuffer = pTempBuffer + m_pFrameCache[i].nCacheBufLenth;

										memcpy(pH264Nal+nTempBufLenth, m_pFrameCache[lRealHandle][i].pCacheBuffer, 
											m_pFrameCache[lRealHandle][i].nCacheBufLenth);
										nTempBufLenth += m_pFrameCache[lRealHandle][i].nCacheBufLenth;
									}
									if (m_pFrameCache[lRealHandle][i].pCacheBuffer)
									{
										delete [](m_pFrameCache[lRealHandle][i].pCacheBuffer);
										m_pFrameCache[lRealHandle][i].pCacheBuffer = NULL;
									}	
									m_pFrameCache[lRealHandle][i].nCacheBufLenth = 0; 
								}

								if (m_bRtmpRunning && pH264Nal && nTempBufLenth>0)
								{
									BOOL bIsKeyFrame = FALSE;
									//查找是否為關鍵幀
									if(pH264Nal[4]==0x67)
									{
										bIsKeyFrame = TRUE;
									}
									long lTimeStamp = clock();
									WriteH264DataToChace(lRealHandle, pH264Nal, nTempBufLenth, bIsKeyFrame, lTimeStamp);
								}

								if (pH264Nal)
								{
									delete []pH264Nal;
									pH264Nal = NULL;
								}
								// 緩存數據個數 清0
								m_mFrameCacheLenth[lRealHandle] = 0;
							}
						}
					}
				}
			}

通過對上述代碼的分析，整個視頻流回調過程還是比較簡單的：判斷回調數據類型（NET_DVR_STREAMDATA）–》海康PS數據Demux成音視頻ES數據（GetH246FromPS）–》對關鍵幀數據做緩存和處理（bIsKeyFrame ）–》進入轉推RTMP緩存隊列（WriteH264DataToChace）

海康PS流解析：

BOOL CDecCallBack_DemoDlg::GetH246FromPS(IN BYTE* pBuffer, IN int nBufLenth, BYTE** pH264, int& nH264Lenth, BOOL& bVideo)
{
	if (!pBuffer || nBufLenth<=0)
	{
		return FALSE;
	}

	BYTE* pH264Buffer = NULL;
	int nHerderLen = 0;
	
	if( pBuffer
		&& pBuffer[0]==0x00
		&& pBuffer[1]==0x00 
		&& pBuffer[2]==0x01
		&& pBuffer[3]==0xE0)//E==視頻數據(此處E0標識為視頻)
	{
		bVideo = TRUE;
		nHerderLen = 9 + (int)pBuffer[8];//9個為固定的數據包頭長度，pBuffer[8]為填充頭部分的長度
		pH264Buffer = pBuffer+nHerderLen;
		if (*pH264 == NULL)
		{
			*pH264 = new BYTE[nBufLenth];
		}
		if (*pH264&&pH264Buffer&&(nBufLenth-nHerderLen)>0)
		{	
			memcpy(*pH264, pH264Buffer, (nBufLenth-nHerderLen));
		}	
		nH264Lenth = nBufLenth-nHerderLen;
	
		return TRUE;
	}	
	else if(pBuffer 
		&& pBuffer[0]==0x00
		&& pBuffer[1]==0x00
		&& pBuffer[2]==0x01
		&& pBuffer[3]==0xC0) //C==音頻數據
	{
		*pH264 = NULL;
		nH264Lenth = 0;
		bVideo = FALSE;
	}
	else if(pBuffer 
		&& pBuffer[0]==0x00
		&& pBuffer[1]==0x00
		&& pBuffer[2]==0x01
		&& pBuffer[3]==0xBA)//視頻流數據包 包頭
	{
		bVideo = TRUE;
		*pH264 = NULL;
		nH264Lenth = 0;
		return FALSE;
	}
	return FALSE;
}

海康音視頻數據進行RTMP推流：

int CDecCallBack_DemoDlg::WriteH264DataToChace(int nDevId, BYTE* pBuffer, int nBufSize, BOOL bIsKeyFrame, long lTimeStamp)
{
	if (!pBuffer || nBufSize<=0 || lTimeStamp<0)
	{
		return -1;
	}

	BOOL bKeyFrame  = bIsKeyFrame;
	int nDeviceType = nDevId+1;
	if (m_RtmpHandle && m_bRtmpRunning)
	{
		//H264推送RTMP
		EASY_AV_Frame	avFrame;
		memset(&avFrame, 0x00, sizeof(EASY_AV_Frame));

		avFrame.pBuffer = (unsigned char*)pBuffer;
		avFrame.u32AVFrameLen = nBufSize;
		avFrame.u32VFrameType = (bKeyFrame)?EASY_SDK_VIDEO_FRAME_I:EASY_SDK_VIDEO_FRAME_P;
		avFrame.u32AVFrameFlag = EASY_SDK_VIDEO_FRAME_FLAG;
		avFrame.u32TimestampSec = lTimeStamp/1000000;
		avFrame.u32TimestampUsec = (lTimeStamp%1000000);

		//EnterCriticalSection(&m_cs);
		EasyRTMP_SendPacket(m_RtmpHandle, &avFrame);	
	}

	return 1;
}

經過上述步驟，基本完成了對一路SDK數據回調的處理，如果需要一個完整的、系統的、中間件級別的流轉服務，那還需要一套完整的控制機制和配套接口以及前端界面，就類似於EasyNVR一樣。

本文中所述詳細代碼見：https://github.com/EasyDSS/EasyRTMP/tree/master/EasyRTMP_HIK