winutil.h

mediastreamer2是开源的网络传输媒体流的库

    void NotifyAllocator(BOOL bUsingImageAllocator);
    void NotifyMediaType(CMediaType *pMediaType);
    BOOL UsingImageAllocator();

    // Called when we are about to draw an image

    void NotifyStartDraw() {
        MSR_START(m_perfidRenderTime);
    };

    // Called when we complete an image rendering

    void NotifyEndDraw() {
        MSR_STOP(m_perfidRenderTime);
    };
};


// This is the structure used to keep information about each GDI DIB. All the
// samples we create from our allocator will have a DIBSECTION allocated to
// them. When we receive the sample we know we can BitBlt straight to an HDC

typedef struct tagDIBDATA {

    LONG        PaletteVersion;     // Current palette version in use
    DIBSECTION  DibSection;         // Details of DIB section allocated
    HBITMAP     hBitmap;            // Handle to bitmap for drawing
    HANDLE      hMapping;           // Handle to shared memory block
    BYTE        *pBase;             // Pointer to base memory address

} DIBDATA;


// This class inherits from CMediaSample and uses all of it's methods but it
// overrides the constructor to initialise itself with the DIBDATA structure
// When we come to render an IMediaSample we will know if we are using our own
// allocator, and if we are, we can cast the IMediaSample to a pointer to one
// of these are retrieve the DIB section information and hence the HBITMAP

class CImageSample : public CMediaSample
{
protected:

    DIBDATA m_DibData;      // Information about the DIBSECTION
    BOOL m_bInit;           // Is the DIB information setup

public:

    // Constructor

    CImageSample(CBaseAllocator *pAllocator,
                 TCHAR *pName,
                 HRESULT *phr,
                 LPBYTE pBuffer,
                 LONG length);

    // Maintain the DIB/DirectDraw state

    void SetDIBData(DIBDATA *pDibData);
    DIBDATA *GetDIBData();
};


// This is an allocator based on the abstract CBaseAllocator base class that
// allocates sample buffers in shared memory. The number and size of these
// are determined when the output pin calls Prepare on us. The shared memory
// blocks are used in subsequent calls to GDI CreateDIBSection, once that
// has been done the output pin can fill the buffers with data which will
// then be handed to GDI through BitBlt calls and thereby remove one copy

class CImageAllocator : public CBaseAllocator
{
protected:

    CBaseFilter *m_pFilter;   // Delegate reference counts to
    CMediaType *m_pMediaType;           // Pointer to the current format

    // Used to create and delete samples

    HRESULT Alloc();
    void Free();

    // Manage the shared DIBSECTION and DCI/DirectDraw buffers

    HRESULT CreateDIB(LONG InSize,DIBDATA &DibData);
    STDMETHODIMP CheckSizes(ALLOCATOR_PROPERTIES *pRequest);
    virtual CImageSample *CreateImageSample(LPBYTE pData,LONG Length);

public:

    // Constructor and destructor

    CImageAllocator(CBaseFilter *pFilter,TCHAR *pName,HRESULT *phr);
#ifdef DEBUG
    ~CImageAllocator();
#endif

    STDMETHODIMP_(ULONG) NonDelegatingAddRef();
    STDMETHODIMP_(ULONG) NonDelegatingRelease();
    void NotifyMediaType(CMediaType *pMediaType);

    // Agree the number of buffers to be used and their size

    STDMETHODIMP SetProperties(
        ALLOCATOR_PROPERTIES *pRequest,
        ALLOCATOR_PROPERTIES *pActual);
};


// This class is a fairly specialised helper class for image renderers that
// have to create and manage palettes. The CBaseWindow class looks after
// realising palettes once they have been installed. This class can be used
// to create the palette handles from a media format (which must contain a
// VIDEOINFO structure in the format block). We try to make the palette an
// identity palette to maximise performance and also only change palettes
// if actually required to (we compare palette colours before updating).
// All the methods are virtual so that they can be overriden if so required

class CImagePalette
{
protected:

    CBaseWindow *m_pBaseWindow;             // Window to realise palette in
    CBaseFilter *m_pFilter;                 // Media filter to send events
    CDrawImage *m_pDrawImage;               // Object who will be drawing
    HPALETTE m_hPalette;                    // The palette handle we own

public:

    CImagePalette(CBaseFilter *pBaseFilter,
                  CBaseWindow *pBaseWindow,
                  CDrawImage *pDrawImage);

#ifdef DEBUG
    virtual ~CImagePalette();
#endif

    static HPALETTE MakePalette(const VIDEOINFOHEADER *pVideoInfo, LPSTR szDevice);
    HRESULT RemovePalette();
    static HRESULT MakeIdentityPalette(PALETTEENTRY *pEntry,INT iColours, LPSTR szDevice);
    HRESULT CopyPalette(const CMediaType *pSrc,CMediaType *pDest);
    BOOL ShouldUpdate(const VIDEOINFOHEADER *pNewInfo,const VIDEOINFOHEADER *pOldInfo);
    HRESULT PreparePalette(const CMediaType *pmtNew,const CMediaType *pmtOld,LPSTR szDevice);

    BOOL DrawVideoImageHere(HDC hdc, IMediaSample *pMediaSample, LPRECT lprcSrc, LPRECT lprcDst)
    {
        return m_pDrawImage->DrawVideoImageHere(hdc, pMediaSample, lprcSrc,lprcDst);
    }
};


// Another helper class really for video based renderers. Most such renderers
// need to know what the display format is to some degree or another. This
// class initialises itself with the display format. The format can be asked
// for through GetDisplayFormat and various other accessor functions. If a
// filter detects a display format change (perhaps it gets a WM_DEVMODECHANGE
// message then it can call RefreshDisplayType to reset that format). Also
// many video renderers will want to check formats as they are proposed by
// source filters. This class provides methods to check formats and only
// accept those video formats that can be efficiently drawn using GDI calls

class CImageDisplay : public CCritSec
{
protected:

    // This holds the display format; biSize should not be too big, so we can
    // safely use the VIDEOINFO structure
    VIDEOINFO m_Display;

    static DWORD CountSetBits(const DWORD Field);
    static DWORD CountPrefixBits(const DWORD Field);
    static BOOL CheckBitFields(const VIDEOINFO *pInput);

public:

    // Constructor and destructor

    CImageDisplay();

    // Used to manage BITMAPINFOHEADERs and the display format

    const VIDEOINFO *GetDisplayFormat();
    HRESULT RefreshDisplayType(LPSTR szDeviceName);
    static BOOL CheckHeaderValidity(const VIDEOINFO *pInput);
    static BOOL CheckPaletteHeader(const VIDEOINFO *pInput);
    BOOL IsPalettised();
    WORD GetDisplayDepth();

    // Provide simple video format type checking

    HRESULT CheckMediaType(const CMediaType *pmtIn);
    HRESULT CheckVideoType(const VIDEOINFO *pInput);
    HRESULT UpdateFormat(VIDEOINFO *pVideoInfo);
    const DWORD *GetBitMasks(const VIDEOINFO *pVideoInfo);

    BOOL GetColourMask(DWORD *pMaskRed,
                       DWORD *pMaskGreen,
                       DWORD *pMaskBlue);
};

//  Convert a FORMAT_VideoInfo to FORMAT_VideoInfo2
STDAPI ConvertVideoInfoToVideoInfo2(AM_MEDIA_TYPE *pmt);

#endif // __WINUTIL__