ipfilter.h

简单的COM 实际例子 用法1

//
// Sample DirectShow In-Place Transform Filter that accepts data for use in application
//

#include <streams.h>

// This is an example in-place transform filter that is created within
// the application, and not by CoCreateInstance
class CAppTransform : public CTransInPlaceFilter
{
public:
    CAppTransform(LPUNKNOWN pUnkOuter, HRESULT *phr);

    HRESULT CheckInputType(const CMediaType* mtIn);
    HRESULT Transform(IMediaSample *pSample);
};


// DirectShow graph management sample code:
// This builds a playback graph using RenderFile
// and then inserts a transform filter on the uncompressed video.
class CAppGraphBuilder
{
private:
	CAppTransform*   m_pFilter;
    IGraphBuilder*   m_pGraph;
	DWORD		     m_dwObjectTable; 

public:
    CAppGraphBuilder();
    ~CAppGraphBuilder();

    void DestroyGraph(void);

    HRESULT BuildFromFile(LPCWSTR pszFile);
    HRESULT Run(void);
    HRESULT MakeChild(HWND hwnd);
    HRESULT ResizeVideoWindow(RECT* prc);

private:
	void CreateAppFilter(void);
	HRESULT FindFilterByInterface(REFIID riid, IBaseFilter** ppFilter);
	HRESULT ConnectUpstreamOf(IBaseFilter* pFilter, IBaseFilter* pTransform);
	HRESULT NextUpstream(IBaseFilter* pFilter, IBaseFilter** ppNext);   

	IPin* GetPin(IBaseFilter* pFilter, PIN_DIRECTION dirRequest);
	// Helper methods
	IPin* InputPinOf(IBaseFilter* pFilter) 
	{
		return GetPin(pFilter, PINDIR_INPUT);
	}
	IPin* OutputPinOf(IBaseFilter* pFilter) 
	{
		return GetPin(pFilter, PINDIR_OUTPUT);
	}

	void AddToObjectTable(void) ;
	void RemoveFromObjectTable(void);
};