directshow命令

//枚举设备IMoniker
IEnumMoniker *pEm=NULL;    
hr=pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pEm,0);
pEm->Reset();              
ULONG cFetched;
IMoniker *pM=NULL;           
	while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK) //获取下一个设备
	{
		IPropertyBag *pBag;            //属性页接口指针
		hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void **)&pBag);
		//获取设备属性页
			if(SUCCEEDED(hr)) 
			{
				VARIANT var;
				var.vt = VT_BSTR;       //保存的是二进制数据
				hr = pBag->Read(L"FriendlyName", &var, NULL);
				//获取FriendlyName形式的信息


				if (hr == NOERROR) 
					{
					//	if (id == 1) 
							hr=pM->BindToObject(0, 0, IID_IBaseFilter, (void**)&pFilter);
							SysFreeString(var.bstrVal); //释放二进制数据资源，必须释放
					 }   

				 if (SUCCEEDED(hr)) 
					  { 
						hr = m_pGB->AddFilter(pFilter, L"Capture Filter"); 
						

						if (FAILED(hr))
						{
							printf("2");
						}



						if (SUCCEEDED(hr)) 
						 { 
							 printf("1");
							 break;
						 }
					  } 
				
				pBag->Release();  
						}
		pM->Release();            
		
	}

HRESULT GetPin(IBaseFilter *pFilter, PIN_DIRECTION PinDir, IPin **ppPin) //查找一个输出和输入 pin。利用 PIN_DIRECTION 参数来制定 pin的类型（输入还是输出）。
{
	IEnumPins *pEnum = NULL;
	IPin *pPin = NULL; 
	HRESULT hr; 
	if (ppPin == NULL) 
	{
	return E_POINTER; 
	}
	hr = pFilter->EnumPins(&pEnum);
	if (FAILED(hr))
	{
	return hr; 
	}
	while(pEnum->Next(1, &pPin, 0) == S_OK) 
	{
		PIN_DIRECTION PinDirThis; 
		hr = pPin->QueryDirection(&PinDirThis);
		    if (FAILED(hr))
			{
			pPin->Release(); 
			pEnum->Release(); 
			return hr; 
			}
			if (PinDir == PinDirThis) //如果类型符合
			{
			// Found a match. Return the IPin pointer to the caller. 
			//**ppPin = pPin;
				*ppPin = pPin;
			pEnum->Release(); 
			return S_OK; 
			}

		// Release the pin for the next time through the loop.
		pPin->Release(); 
	}
	// No more pins. We did not find a match.
	pEnum->Release();
	return E_FAIL;
}

//利用 CLSID 生成一个 filter，然后将其加入到 graph
//在你的应用程序中，你可以这样用这个函数
//IBaseFilter *pMux;
//hr = AddFilterByCLSID(pGraph, CLSID_AviDest, L"AVI Mux", &pMux);
//if (SUCCEEDED(hr))
//{
//pMux->Release();
//}

HRESULT AddFilterByCLSID(
									IGraphBuilder *pGraph, // Pointer to the Filter Graph Manager. 
									const GUID& clsid, // CLSID of the filter to create.
									LPCWSTR wszName, // A name for the filter. 
									IBaseFilter **ppF// Receives a pointer to the filter. 
									
						 ) 

{
	if (!pGraph || ! ppF) 
	return E_POINTER;
	*ppF = 0;
	IBaseFilter *pF = 0;
	HRESULT hr = CoCreateInstance(clsid, 0, CLSCTX_INPROC_SERVER,IID_IBaseFilter, reinterpret_cast(&pF));
	if (SUCCEEDED(hr))
	{
	hr = pGraph->AddFilter(pF, wszName);
	if (SUCCEEDED(hr))
	*ppF = pF;
	else 
		
	pF->Release(); 

	}
	return hr; 
}

//hr = SaveGraphFile(m_pGB, L"C:\\newMyGraph.grf");保存graphedit
HRESULT SaveGraphFile(IGraphBuilder *pGraph, WCHAR *wszPath) 
{
	const WCHAR wszStreamName[] = L"ActiveMovieGraph";
	HRESULT hr; 
	IStorage *pStorage = NULL;
	hr = StgCreateDocfile(
			wszPath, 
			STGM_CREATE | STGM_TRANSACTED | STGM_READWRITE | STGM_SHARE_EXCLUSIVE,
			0, &pStorage
			);

	if(FAILED(hr))

	{
	return hr; 
	}
	
	IStream *pStream;

	hr = pStorage->CreateStream(
		wszStreamName, STGM_WRITE | STGM_CREATE | STGM_SHARE_EXCLUSIVE,
		0, 0, &pStream
		); 
	
	if (FAILED(hr))
	{
	pStorage->Release(); 
	return hr; 
	}
	IPersistStream *pPersist = NULL;

	pGraph->QueryInterface(IID_IPersistStream, (void**)&pPersist);
	hr = pPersist->Save(pStream, TRUE);
	pStream->Release();
	pPersist->Release();

	if (SUCCEEDED(hr))
	{
	hr = pStorage->Commit(STGC_DEFAULT); 
	}

	pStorage->Release();
	return hr; 

}

//枚举Graph中filter
HRESULT EnumFilters (IFilterGraph *pGraph) 
{
IEnumFilters *pEnum = NULL;
IBaseFilter *pFilter;
ULONG cFetched1;

HRESULT hr = pGraph->EnumFilters(&pEnum);

     while(pEnum->Next(1, &pFilter, &cFetched1) == S_OK)
      {
       FILTER_INFO FilterInfo;
       hr = pFilter->QueryFilterInfo(&FilterInfo);
	   printf("11");
	  FilterInfo.pGraph->Release();
         }

pFilter->Release();

pEnum->Release();

return hr; 
}