MFC+DirectShow摄像头简单视频浏览

1 安装摄像头驱动

 

2 引用DirectShow库，包含DirectShow头文件

#pragma comment(lib,"Strmiids.lib")

#pragma comment(lib,"quartz.lib")

#include "dshow.h"

 

3 初始化com环境

::CoInitialize(NULL);

 

4 定义一个过滤器引脚查询函数,并实现之

  定义

IPin *findpin(IBaseFilter *pFilter,PIN_DIRECTION dir);

 实现，假定工程为MFC Dialog Based类型，主对话框类为VDlg

IPin *VDlg::findpin(IBaseFilter *pFilter,PIN_DIRECTION dir)

{

  IEnumPins *pEnumPins=NULL;

  IPin            *pRetPin=NULL;

  PIN_DIRECTION pDir;

  pFilter->EnumPins(&pEnumPins);

  while(pEnumPins->Next(1,&pRetPin,NULL)==S_OK)

  {

    pRectPin->QueryDirection(&pDir);

    if(pDir==dir)

    {

       return pRetPin;

    }

  }

  return 0;

}

 

5 预览实现

void VDlg::vPreview()

{

  ICaptureGraphBuilder *pBuilder=NULL;

  ::CoCreateInstance(CLSID_CaptureGraphBuilder2,NULL,CLSCTX_INPROC_SERVER,IID_ICaptureGraphBuilder2,(void **)&pBuilder);

  ::CoCreateInstance(CLSID_FilterGraph,NULL,CLSCTX_INPROC_SERVER,IID_IGraphBuilder,(void **)&pGraph);

  pBuilder->SetFiltergraph(pGraph);

  ICreateDevEnum *pDevEnum=NULL;

  IEnumMoniker *pClsEnum=NULL;

  ::CoCreateInstance(CLSID_SystemDeviceEnum,NULL,CLSCTX_INPROC,IID_ICreateDevEnum,(void **)&pDevEnum);

  pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pClsEnum,0);

  if(pClsEnum->Next(1,&pMoniker,NULL)==S_OK)

  {

    pMoniker->BindToObject(0,0,IID_IBaseFilter,(void **)&pSrc);

    pMoniker->Release();

   }

   pClsEnum->Release();

  

   pGraph->AddFilter(pSrc,L"AVI");

   ::CoCreateInstance(CLSID_VideoRenderer,NULL,CLSCTX_ALL,IID_IBaseFilter,(void **)&pPreview);

   if(pPreview)

   {

     pGraph->AddFilter(pPreview,L"PREVIEW");

     IPin *pPinOut,*pPinIn;

     pPinOut=findpin(pSrc,PINDIR_OUTPUT);

     pPinIn=findpin(pPreview,PINDIR_INPUT);

     pGraph->ConnectDirect(pPinOut,pPinIn,0);

    

     IVideoWindow *pWnd=NULL;

     pPreview->QueryInterface(IID_IVideowindow,(void **)&pWnd);

     if(pWnd)

     {

          long ws;

          pWnd->put_Owner((long)m_hWnd);

          pWnd->get_WindowStyle(&ws);

          ws=ws &~ WS_CAPTION;

          ws=ws &~WS_DLGFRAME;

          ws=ws & WS_CHILD;

          pWnd->put_WindowStyle(ws);

         

          CRect rc;

          this->GetClientRect(rc);

          pWnd->put_Lef(5);

          pWnd->put_Top(5);

          pWnd->put_Width(rc.Width()-5);

          pWnd->put_Height(rc.Height()-5);

      }

     pMediaCtrl->Run();

   }

}