STDMETHOD(GetInputPinCount)(THIS_ int *piPinCount) PURE;
    STDMETHOD(IsUsingClock)(THIS_ int *pbValue) PURE;
    STDMETHOD(SetUsingClock)(THIS_ int bValue) PURE;
    STDMETHOD(GetClockPeriod)(THIS_ int *pbValue) PURE;
    STDMETHOD(SetClockPeriod)(THIS_ int bValue) PURE;
};

#define iPALETTE_COLORS 256     // Maximum colours in palette
#define iEGA_COLORS 16          // Number colours in EGA palette
#define iMASK_COLORS 3          // Maximum three components
#define iTRUECOLOR 16           // Minimum true colour device
#define iRED 0                  // Index position for RED mask
#define iGREEN 1                // Index position for GREEN mask
#define iBLUE 2                 // Index position for BLUE mask
#define iPALETTE 8              // Maximum colour depth using a palette
#define iMAXBITS 8              // Maximum bits per colour component


// Used for true colour images that also have a palette

typedef struct tag_TRUECOLORINFO {
    DWORD   dwBitMasks[iMASK_COLORS];
    RGBQUAD bmiColors[iPALETTE_COLORS];
} TRUECOLORINFO;


// The BITMAPINFOHEADER contains all the details about the video stream such
// as the actual image dimensions and their pixel depth. A source filter may
// also request that the sink take only a section of the video by providing a
// clipping rectangle in rcSource. In the worst case where the sink filter
// forgets to check this on connection it will simply render the whole thing
// which isn't a disaster. Ideally a sink filter will check the rcSource and
// if it doesn't support image extraction and the rectangle is not empty then
// it will reject the connection. A filter should use SetRectEmpty to reset a
// rectangle to all zeroes (and IsRectEmpty to later check the rectangle).
// The rcTarget specifies the destination rectangle for the video, for most
// source filters they will set this to all zeroes, a downstream filter may
// request that the video be placed in a particular area of the buffers it
// supplies in which case it will call QueryAccept with a non empty target

typedef struct tagVIDEOINFOHEADER {

    RECT            rcSource;          // The bit we really want to use
    RECT            rcTarget;          // Where the video should go
    DWORD           dwBitRate;         // Approximate bit data rate
    DWORD           dwBitErrorRate;    // Bit error rate for this stream
    REFERENCE_TIME  AvgTimePerFrame;   // Average time per frame (100ns units)

    BITMAPINFOHEADER bmiHeader;

} VIDEOINFOHEADER;

// make sure the pbmi is initialized before using these macros
#define TRUECOLOR(pbmi)  ((TRUECOLORINFO *)(((LPBYTE)&((pbmi)->bmiHeader)) \
					+ (pbmi)->bmiHeader.biSize))
#define COLORS(pbmi)	((RGBQUAD *)(((LPBYTE)&((pbmi)->bmiHeader)) 	\
					+ (pbmi)->bmiHeader.biSize))
#define BITMASKS(pbmi)	((DWORD *)(((LPBYTE)&((pbmi)->bmiHeader)) 	\
					+ (pbmi)->bmiHeader.biSize))

// All the image based filters use this to communicate their media types. It's
// centred principally around the BITMAPINFO. This structure always contains a
// BITMAPINFOHEADER followed by a number of other fields depending on what the
// BITMAPINFOHEADER contains. If it contains details of a palettised format it
// will be followed by one or more RGBQUADs defining the palette. If it holds
// details of a true colour format then it may be followed by a set of three
// DWORD bit masks that specify where the RGB data can be found in the image
// (For more information regarding BITMAPINFOs see the Win32 documentation)

// The rcSource and rcTarget fields are not for use by filters supplying the
// data. The destination (target) rectangle should be set to all zeroes. The
// source may also be zero filled or set with the dimensions of the video. So
// if the video is 352x288 pixels then set it to (0,0,352,288). These fields
// are mainly used by downstream filters that want to ask the source filter
// to place the image in a different position in an output buffer. So when
// using for example the primary surface the video renderer may ask a filter
// to place the video images in a destination position of (100,100,452,388)
// on the display since that's where the window is positioned on the display

// !!! WARNING !!!
// DO NOT use this structure unless you are sure that the BITMAPINFOHEADER
// has a normal biSize == sizeof(BITMAPINFOHEADER) !
// !!! WARNING !!!

typedef struct tagVIDEOINFO {

    RECT            rcSource;          // The bit we really want to use
    RECT            rcTarget;          // Where the video should go
    DWORD           dwBitRate;         // Approximate bit data rate
    DWORD           dwBitErrorRate;    // Bit error rate for this stream
    REFERENCE_TIME  AvgTimePerFrame;   // Average time per frame (100ns units)

    BITMAPINFOHEADER bmiHeader;

    union {
        RGBQUAD         bmiColors[iPALETTE_COLORS];     // Colour palette
        DWORD           dwBitMasks[iMASK_COLORS];       // True colour masks
        TRUECOLORINFO   TrueColorInfo;                  // Both of the above
    };

} VIDEOINFO;

// These macros define some standard bitmap format sizes

#define SIZE_EGA_PALETTE (iEGA_COLORS * sizeof(RGBQUAD))
#define SIZE_PALETTE (iPALETTE_COLORS * sizeof(RGBQUAD))
#define SIZE_MASKS (iMASK_COLORS * sizeof(DWORD))
#define SIZE_PREHEADER (FIELD_OFFSET(VIDEOINFOHEADER,bmiHeader))
#define SIZE_VIDEOHEADER (sizeof(BITMAPINFOHEADER) + SIZE_PREHEADER)
// !!! for abnormal biSizes
// #define SIZE_VIDEOHEADER(pbmi) ((pbmi)->bmiHeader.biSize + SIZE_PREHEADER)

// DIBSIZE calculates the number of bytes required by an image

#define WIDTHBYTES(bits) ((DWORD)(((bits)+31) & (~31)) / 8)
#define DIBWIDTHBYTES(bi) (DWORD)WIDTHBYTES((DWORD)(bi).biWidth * (DWORD)(bi).biBitCount)
#define _DIBSIZE(bi) (DIBWIDTHBYTES(bi) * (DWORD)(bi).biHeight)
#define DIBSIZE(bi) ((bi).biHeight < 0 ? (-1)*(_DIBSIZE(bi)) : _DIBSIZE(bi))

// This compares the bit masks between two VIDEOINFOHEADERs

#define BIT_MASKS_MATCH(pbmi1,pbmi2)                                \
    (((pbmi1)->dwBitMasks[iRED] == (pbmi2)->dwBitMasks[iRED]) &&        \
     ((pbmi1)->dwBitMasks[iGREEN] == (pbmi2)->dwBitMasks[iGREEN]) &&    \
     ((pbmi1)->dwBitMasks[iBLUE] == (pbmi2)->dwBitMasks[iBLUE]))

// These zero fill different parts of the VIDEOINFOHEADER structure

// Only use these macros for pbmi's with a normal BITMAPINFOHEADER biSize
#define RESET_MASKS(pbmi) (ZeroMemory((PVOID)(pbmi)->dwBitFields,SIZE_MASKS))
#define RESET_HEADER(pbmi) (ZeroMemory((PVOID)(pbmi),SIZE_VIDEOHEADER))
#define RESET_PALETTE(pbmi) (ZeroMemory((PVOID)(pbmi)->bmiColors,SIZE_PALETTE));

#if 0
// !!! This is the right way to do it, but may break existing code
#define RESET_MASKS(pbmi) (ZeroMemory((PVOID)(((LPBYTE)(pbmi)->bmiHeader) + \
			(pbmi)->bmiHeader.biSize,SIZE_MASKS)))
#define RESET_HEADER(pbmi) (ZeroMemory((PVOID)(pbmi), SIZE_PREHEADER +	    \
			sizeof(BITMAPINFOHEADER)))
#define RESET_PALETTE(pbmi) (ZeroMemory((PVOID)(((LPBYTE)(pbmi)->bmiHeader) + \
			(pbmi)->bmiHeader.biSize,SIZE_PALETTE))
#endif

// Other (hopefully) useful bits and bobs

#define PALETTISED(pbmi) ((pbmi)->bmiHeader.biBitCount <= iPALETTE)
#define PALETTE_ENTRIES(pbmi) ((DWORD) 1 << (pbmi)->bmiHeader.biBitCount)

// Returns the address of the BITMAPINFOHEADER from the VIDEOINFOHEADER
#define HEADER(pVideoInfo) (&(((VIDEOINFOHEADER *) (pVideoInfo))->bmiHeader))


// MPEG variant - includes a DWORD length followed by the
// video sequence header after the video header.
//
// The sequence header includes the sequence header start code and the
// quantization matrices associated with the first sequence header in the
// stream so is a maximum of 140 bytes long.

typedef struct tagMPEG1VIDEOINFO {

    VIDEOINFOHEADER hdr;                    // Compatible with VIDEOINFO
    DWORD           dwStartTimeCode;        // 25-bit Group of pictures time code
                                            // at start of data
    DWORD           cbSequenceHeader;       // Length in bytes of bSequenceHeader
    BYTE            bSequenceHeader[1];     // Sequence header including
                                            // quantization matrices if any
} MPEG1VIDEOINFO;

#define MAX_SIZE_MPEG1_SEQUENCE_INFO 140
#define SIZE_MPEG1VIDEOINFO(pv) (FIELD_OFFSET(MPEG1VIDEOINFO, bSequenceHeader[0]) + (pv)->cbSequenceHeader)
#define MPEG1_SEQUENCE_INFO(pv) ((const BYTE *)(pv)->bSequenceHeader)


// Analog video variant - Use this when the format is FORMAT_AnalogVideo
//
// rcSource defines the portion of the active video signal to use
// rcTarget defines the destination rectangle
//    both of the above are relative to the dwActiveWidth and dwActiveHeight fields
// dwActiveWidth is currently set to 720 for all formats (but could change for HDTV)
// dwActiveHeight is 483 for NTSC and 575 for PAL/SECAM  (but could change for HDTV)

typedef struct tagAnalogVideoInfo {
    RECT            rcSource;           // Width max is 720, height varies w/ TransmissionStd
    RECT            rcTarget;           // Where the video should go
    DWORD           dwActiveWidth;      // Always 720 (CCIR-601 active samples per line)
    DWORD           dwActiveHeight;     // 483 for NTSC, 575 for PAL/SECAM
    REFERENCE_TIME  AvgTimePerFrame;    // Normal ActiveMovie units (100 nS)
} ANALOGVIDEOINFO;

//
// AM_KSPROPSETID_FrameStep property set definitions
//
typedef enum {
        //  Step
	AM_PROPERTY_FRAMESTEP_STEP   = 0x01,
	AM_PROPERTY_FRAMESTEP_CANCEL = 0x02,

        //  S_OK for these 2 means we can - S_FALSE if we can't
        AM_PROPERTY_FRAMESTEP_CANSTEP = 0x03,
        AM_PROPERTY_FRAMESTEP_CANSTEPMULTIPLE = 0x04
} AM_PROPERTY_FRAMESTEP;

typedef struct _AM_FRAMESTEP_STEP
{
    //  1 means step 1 frame forward
    //  0 is invalid
    //  n (n > 1) means skip n - 1 frames and show the nth
    DWORD dwFramesToStep;
} AM_FRAMESTEP_STEP;

#ifdef __cplusplus
}
#endif // __cplusplus
#endif // __AMVIDEO__