C++驱动摄像头图像采集示例：从设备枚举到滤波器实现

#include   "stdafx.h"   
    
  #include   <stdio.h>   
  #include   <basetsd.h>   
  #include   <vector>   
  #include   <dshow.h>   
    
  int   main(int   argc,   char*   argv[])   
  {   
    int   i;   
    HRESULT   hr;   
    CComPtr<IGraphBuilder>   graphBuilder;   
    CComPtr<ICaptureGraphBuilder2>   graphBuilder2;   
    CComPtr<ICreateDevEnum>   devEnum;   
    IEnumMoniker   *camEnum   =   NULL;   
    IMoniker   *cam   =   NULL;   
    std::vector<IBaseFilter   *>   camSource;   
    
    //Initialize   COM   
    hr   =   CoInitialize(NULL);   
    if   (FAILED(hr))   exit(1);   
    
    
    //Create   the   graph   builders   
    hr   =   graphBuilder2.CoCreateInstance(CLSID_CaptureGraphBuilder2);   
    if   (FAILED(hr))   exit(1);   
    hr   =   graphBuilder.CoCreateInstance(CLSID_FilterGraph);   
    if   (FAILED(hr))   exit(1);   
    hr   =   graphBuilder2->SetFiltergraph((IGraphBuilder   *)graphBuilder);   
    if   (FAILED(hr))   exit(1);   

    
    //Find   the   cameras   
    hr   =   devEnum.CoCreateInstance(CLSID_SystemDeviceEnum);   
    if   (FAILED(hr))   exit(1);   
    hr   =   devEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,   
  &camEnum,   0);   
    if   (FAILED(hr))   exit(1);   
    
    //Count   the   cameras   and   get   pointers   to   them   
    i   =   0;   
    while   (camEnum->Next(1,   &cam,   NULL)   ==   S_OK)   
    {   
      USES_CONVERSION;   
    
      IPropertyBag   *pPropBag;   
      IBaseFilter   *camSrc;   
      VARIANT   camName;   VariantInit(&camName);   
    
      //Get   the   name   of   the   camera   
      hr   =   cam->BindToStorage(0,   0,   IID_IPropertyBag,   (void   **)&pPropBag);   
      if   (FAILED(hr))   exit(1);   
      hr   =   pPropBag->Read(L"FriendlyName",   &camName,   0);   
      if   (FAILED(hr))   continue;   
      LPCTSTR   cName   =   OLE2T(camName.bstrVal);   
      pPropBag->Release();   
    
      //If   we   found   a   Dragonfly,   create   a   source   filter   for   it   
      if   (!_strnicmp(cName,   "PGR",   3))   
      {   
        printf("Found   a   PGR   camera!\n");