编写C++程序使DirectShow进行视频捕捉

HRESULT InitCaptureGraphBuilder(IGraphBuilder **ppGraph,//Receives the pointer 
                ICaptureGraphBuilder2 **ppBuilder)           //Receives the pointer 
{ 
  if(!ppGraph || !ppBuilder) 
  { 
    return E_POINTER; 
  } 
 
  IGraphBuilder *pGraph = NULL; 
  ICaptureGraphBuilder2 *pBuild = NULL; 
  //Create the Capture Graph Builder 
  HRESULT hr = CoCreateInstance(CLSID_CaptureGraphBuilder2,NULL,CLSCTX_INPROC_SERVER,IID_ICaptureGraphBuilder2,(void**)&pGraph); 
 
  if(SECCEEDED(hr)) 
  { 
    //Create the Filter Graph Manager 
    hr = CoCreateInstance(CLSID_FilterGraph,IID_IGraphBuilder,(void**)&pGraph); 
    if(SECCEEDED(hr)) 
    { 
      //Initialize the Capture Graph Builder 
      pBuild->SetFiltergraph(pGraph); 
      //Return both interface pointers to the caller 
      *ppBuild = pBuild; 
      *ppGraph = pGraph;   //The caller must release both interface 
      return S_OK; 
    } 
    else  
    { 
      pBuild->Release(); 
    } 
  } 
  return hr;     //Failed 
} 

ICreateDevEnum *pDevEnum = NULL; 
IEnumMoniker *pEnum = NULL; 
 
//Create the system device enumerator 
HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum,CLSCT_INPROC_SERVER,IID_ICreateDevEnum,reinterpret_cast<void**>(&pDevEnum)); 
 
if(SUCCEEDED(hr)) 
{ 
  //创建一个枚举器，枚举视频设备 
  hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pEnum,0); 
} 

HWND hList;     //Handle to the list box 
IMoniker *pMoniker = NULL; 
while(pEnum->Next(1,&pMoniker,NULL) == S_OK) 
{ 
  IPropertyBag *pPropBag; 
  hr = pMoniker->BindToStorage(0,IID_IPropertyBag,(void**)(&pPropBag)); 
  if(FAILED(hr)) 
  { 
    pMoniker->Release(); 
    continue;    //Skip this one,maybe the next one will work 
  } 
  VARIANT varName; 
  hr = pPropBag->Read(L"Description",&varName,0); 
  if(FAILED(hr)) 
  { 
    hr = pPropBag->Read(L"FriendlyName",0); 
  } 
  if(SECCEEDED(hr)) 
  { 
    //Add it to the application's list box 
    USES_CONVERSION; 
    (long)SendMessage(hList,LB_ADDSTRING,(LPARAM)OLE2T(varName.bstrVal)); 
    VariantClear(&varName); 
  } 
 
  pPropBag->Release(); 
  pMoniker->Release(); 
} 

IBaseFilter *pCap = NULL; 
hr = pMoniker->BindToObject(0,IID_IBaseFilter,(void**)&pCap); 
if(SECCEEDED(hr)) 
{ 
  hr = m_pGraph->AddFilter(pCap,L"Capture Filter"); 

ICaptureGraphBuilder2 *pBuild;   //Capture Graph Builder 
//Initialize pBuild(not shown) 
... 
IBaseFilter *pCap;                 //Video capture filter 
hr = pBuild->RenderStream(&PIN_CATEGORY_PREVIEW,&MEDIATYPE_Video,pCap,NULL); 
} 

IBaseFilter *pMux; 
hr = pBuild->SetOutputFileName(&MEDIASUBTYPE_Avi,//Specifies AVI for the target file 
                L"C:Example.avi",//File name 
                &pMux,//Receives a pointer to the mux 
                NULL);    //(Optional)Receives a pointer to the file sink 

hr = pBuild->RenderStream(&PIN_CATEGORY_CAPTURE,//Pin category 
             &MEDIATYPE_Video,//Media type 
             pCap,//Capture filter 
             NULL,//Intermediate filter(optional) 
             pMux);     //Mux or file sink filter 
//Release the mux filter 
pMux->Release(); 

IConfigAviMux *pConfigMux = NULL; 
hr = pMux->QueryInterface(IID_IConfigAviMux,(void**)&pConfigMux); 
if(SUCCEEDED(hr)) 
{ 
  pConfigMux->SetMasterStream(1); 
  pConfigMux->Release(); 
} 

IBaseFilter *pEncoder; 
//Add it to the filter graph 
pGraph->AddFilter(pEncoder,L"Encode"); 
//Render the stream 
hr = pBuild->RenderStream(&PIN_CATEGORY_CAPTURE,pEncoder,pMux); 
pEncoder->Release(); 

IBaseFilter *pASFWriter = 0; 
hr = pBuild->SetOutputFileName(&MEDIASUBTYPE_Asf,//Create a windows media file 
                L"C:VidCap.wmv",//File name 
                &pASFWriter,//Receives a pointer to the filter 
                NULL);        //Receives an IFileSinkFilter interface pointer(optional)

IConfigAsfWriter *pConfig = 0; 
hr = pASFWriter->QueryInterface(IID_IConfigAsfWriter,(void**)&pConfig); 
if(SUCCEEDED(hr)) 
{ 
  //Configure the ASF Writer filter 
  pConfig->Release(); 
} 

hr = pBuild->RenderStream(&PIN_CATEGORY_CAPTURE,//Capture pin 
             &MEDIATYPE_Video,//Video. Use MEDIATYPE_Audio for audio 
             pCap,//Pointer to the capture filter 
             0,pASFWriter);   //Pointer to the sink filter(ASF Filter) 

IBaseFilter *pMux = 0; 
IFileSinkFilter *pSink = 0; 
hr = pBuild->SetOutputFileName(&CLSID_MyCustomMuxFilter,//开发自己的Filter 
                L"C:VidCap.avi",&pMux,&pSink); 
 

IBaseFilter *pMux = 0; 
IFileSinkFilter *pSink = 0; 
hr = pBuild->SetOutputFileName(&MEDIASUBTYPE_Avi,L"C:YourFileName.avi",&pSink); 
if(SUCCEEDED(hr)) 
{ 
  hr = pBuild->RenderStream(&PIN_CATEGORY_CAPTURE,pMux); 
  if(SUCCEEDED(hr)) 
  { 
    pControl->Run(); 
    pControl->Stop(); 
    //Change the file name and run the graph again 
    pSink->SetFileName(L"YourFileName02.avi",0); 
    pControl->Run(); 
  } 
 
  pMux->Release(); 
  pSink->Release(); 
}