最近要使用海康威視攝像機獲取資料做處理。主要是藉助Opencv這個工具，所以做了一下步驟。
我用的是基於Qt+opencv的來顯示海康資料的。本人海康的型號為：DS-2CD2820FD
1、海康sdk開發環境的配置(我只給出我的配置路徑，視具體情況而定)

LIBS += -LD:\Softwares\HaiKang\x64\lib\
-lHCNetSDK \
-lGdiPlus \
-lHCCore \
-lPlayCtrl


LIBS += -LD:\Softwares\HaiKang\x64\lib\HCNetSDKCom\
-lHCAlarm \
-lHCGeneralCfgMgr \
 
-lHCPreview

2、包含的標頭檔案

#include<stdio.h>
#include<iostream>
#include<time.h>
#include<Windows.h>
#include<HCNetSDK.h>
#include<plaympeg4.h>
#include<cstring>


using namespace std;

#include"./opencv2/opencv.hpp"
using namespace  cv;



typedef HWND (WINAPI *PROCGETCONSOLEWINDOW)();
PROCGETCONSOLEWINDOW GetConsoleWindowAPI;
 

3、具體的實現程式碼如下：

LONG nPort=-1; //全域性的播放庫port號
//資料型別轉換
void yv12toYUV(uchar *outYuv, uchar *inYv12, int width, int height,int widthStep)
{
    int col,row;
    unsigned int Y,U,V;
    int tmp;
    int idx;
    for (row=0; row<height; row++)
    {
        idx=row * widthStep;
        for (col=0; col<width; col++)
        {
            tmp = (row/2
 
)*(width/2)+(col/2);
            Y=(unsigned int) inYv12[row*width+col];
            U=(unsigned int) inYv12[width*height+width*height/4+tmp];
            V=(unsigned int) inYv12[width*height+tmp];

            outYuv[idx+col*3]   = Y;
            outYuv[idx+col*3+1] = U;
            outYuv[idx+col*3+2] = V;
        }
    }
}
////解碼回撥 視訊為YUV資料(YV12)
void CALLBACK DecCBFun(long nPort,char * pBuf,long nSize,FRAME_INFO * pFrameInfo, long nReserved1,long nReserved2)
{
    long lFrameType = pFrameInfo->nType;
    if(lFrameType ==T_YV12)
    {
       Mat matYCrCb=Mat(pFrameInfo->nHeight, pFrameInfo->nWidth,CV_8UC3);
       Mat matImge=Mat(pFrameInfo->nHeight, pFrameInfo->nWidth,CV_8UC3);
       yv12toYUV(matYCrCb.data,(uchar*)pBuf,pFrameInfo->nWidth,pFrameInfo->nHeight,matYCrCb.step);
       cvtColor(matYCrCb,matImge,CV_YCrCb2RGB);
       imshow("matImge IPCamera",matImge);
       waitKey(1);//一定記得加不然會出錯
    }
}
void CALLBACK g_RealDataCallBack_V30(LONG lRealHandle, DWORD dwDataType, BYTE *pBuffer,DWORD dwBufSize,void* dwUser)
{
      HWND hWnd=GetConsoleWindowAPI();
      DWORD dRet;
      switch (dwDataType)
      {
      case NET_DVR_SYSHEAD:    //系統頭
          if (!PlayM4_GetPort(&nPort)) //獲取播放庫未使用的通道號
          {
              break;
          }
          if(dwBufSize > 0)
          {
              if (!PlayM4_OpenStream(nPort,pBuffer,dwBufSize,1024*1024))
              {
                  dRet=PlayM4_GetLastError(nPort);
                  break;
              }
              //設定解碼回撥函式 只解碼不顯示
              if (!PlayM4_SetDecCallBack(nPort,DecCBFun))
              {
                  dRet=PlayM4_GetLastError(nPort);
                  break;
              }

              //設定解碼回撥函式 解碼且顯示
              //if (!PlayM4_SetDecCallBackEx(nPort,DecCBFun,NULL,NULL))
              //{
              //  dRet=PlayM4_GetLastError(nPort);
              //  break;
              //}

              //開啟視訊解碼
              if (!PlayM4_Play(nPort,hWnd))
              {
                  dRet=PlayM4_GetLastError(nPort);
                  break;
              }

              //開啟音訊解碼, 需要碼流是複合流
              if (!PlayM4_PlaySound(nPort))
              {
                  dRet=PlayM4_GetLastError(nPort);
                  break;
              }
          }
          break;

      case NET_DVR_STREAMDATA:   //碼流資料
          if (dwBufSize > 0 && nPort != -1)
          {
              BOOL inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
              while (!inData)
              {
                  Sleep(10);
                  inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
                  OutputDebugString(L"PlayM4_InputData failed \n");
              }
          }
          break;
      }
}

void CALLBACK g_ExceptionCallBack(DWORD dwType, LONG lUserID, LONG lHandle, void *pUser)
{
    char tempbuf[256] = {0};
    switch(dwType)
    {
    case EXCEPTION_RECONNECT:    //預覽時重連
    printf("----------reconnect--------%d\n", time(NULL));
    break;
    default:
    break;
    }
}

void main() {

  //---------------------------------------
  // 初始化
  NET_DVR_Init();
  //設定連線時間與重連時間
  NET_DVR_SetConnectTime(2000, 1);
  NET_DVR_SetReconnect(10000, true);

  //---------------------------------------
  //設定異常訊息回撥函式
  NET_DVR_SetExceptionCallBack_V30(0, NULL,g_ExceptionCallBack, NULL);

  //---------------------------------------
  // 獲取控制檯視窗控制代碼
  HMODULE hKernel32 = GetModuleHandle(L"kernel32");
  GetConsoleWindowAPI = (PROCGETCONSOLEWINDOW)GetProcAddress(hKernel32,"GetConsoleWindow");

  //---------------------------------------
  // 註冊裝置
  LONG lUserID;

  //登入引數，包括裝置地址、登入使用者、密碼等
  NET_DVR_USER_LOGIN_INFO struLoginInfo = {0};
  struLoginInfo.bUseAsynLogin = 0; //同步登入方式
  strcpy(struLoginInfo.sDeviceAddress, "192.168.10.64"); //裝置IP地址
  struLoginInfo.wPort = 8000; //裝置服務埠
  strcpy(struLoginInfo.sUserName, "admin"); //裝置登入使用者名稱
  strcpy(struLoginInfo.sPassword, "admin123"); //裝置登入密碼

  //裝置資訊, 輸出引數
  NET_DVR_DEVICEINFO_V40 struDeviceInfoV40 = {0};

  lUserID = NET_DVR_Login_V40(&struLoginInfo, &struDeviceInfoV40);
  if (lUserID < 0)
  {
      printf("Login failed, error code: %d\n", NET_DVR_GetLastError());
      NET_DVR_Cleanup();
      return;
  }

  //---------------------------------------
  //啟動預覽並設定回撥資料流
  LONG lRealPlayHandle;

  NET_DVR_PREVIEWINFO struPlayInfo = {0};
  struPlayInfo.hPlayWnd     = NULL;         //需要SDK解碼時控制代碼設為有效值，僅取流不解碼時可設為空
  struPlayInfo.lChannel     = 1;       //預覽通道號
  struPlayInfo.dwStreamType = 0;       //0-主碼流，1-子碼流，2-碼流3，3-碼流4，以此類推
  struPlayInfo.dwLinkMode   = 0;       //0- TCP方式，1- UDP方式，2- 多播方式，3- RTP方式，4-RTP/RTSP，5-RSTP/HTTP
  struPlayInfo.bBlocked     = 1;       //0- 非阻塞取流，1- 阻塞取流

  lRealPlayHandle = NET_DVR_RealPlay_V40(lUserID, &struPlayInfo, g_RealDataCallBack_V30, NULL);
  if (lRealPlayHandle < 0)
  {
      printf("NET_DVR_RealPlay_V40 error, %d\n", NET_DVR_GetLastError());
      NET_DVR_Logout(lUserID);
      NET_DVR_Cleanup();
      return;
  }

  Sleep(-1);
  //---------------------------------------
  //關閉預覽
  NET_DVR_StopRealPlay(lRealPlayHandle);


  //登出使用者
  NET_DVR_Logout(lUserID);
  NET_DVR_Cleanup();

  return;
}