DDVIDEOPORTCAPS

The DDVIDEOPORTCAPS structure describes the capabilities and alignment restrictions of a video port. This structure is used with the IDDVideoPortContainer::EnumVideoPorts method.

typedef struct _DDVIDEOPORTCAPS { 
    DWORD dwSize;           // Size of the DDVIDEOPORTCAPS structure
    DWORD dwFlags;          // Indicates which fields contain data
    DWORD dwMaxWidth;       // Max width of the video port field
    DWORD dwMaxVBIWidth;    // Max width of the VBI data
    DWORD dwMaxHeight;      // Max height of the video port field
    DWORD dwVideoPortID;    // Video port ID (0 - (dwMaxVideoPorts -1))
    DWORD dwCaps;           // Video port capabilities
    DWORD dwFX;             // More video port capabilities
    DWORD dwNumAutoFlipSurfaces;          // Number of autoflippable surfaces
    DWORD dwAlignVideoPortBoundary;       // Byte restriction of placement within the surface
    DWORD dwAlignVideoPortPrescaleWidth;  // Byte restriction of width after prescaling
    DWORD dwAlignVideoPortCropBoundary;   // Byte restriction of left cropping
    DWORD dwAlignVideoPortCropWidth;      // Byte restriction of cropping width
    DWORD dwPreshrinkXStep;           // Width can be shrunk in steps of 1/x
    DWORD dwPreshrinkYStep;           // Height can be shrunk in steps of 1/x
    DWORD dwNumVBIAutoFlipSurfaces;   // Number of VBI autoflippable surfaces
    DWORD dwReserved1;                // Reserved for future use
    DWORD dwReserved2;                // Reserved for future use
} DDVIDEOPORTCAPS, *LPDDVIDEOPORTCAPS; 
 

Members

dwSize

Size of the structure, in bytes. This must be initialized before use.

dwFlags

Flag values indicating the fields that contain valid data. The following flags are defined.

DDVPD_WIDTH	The dwMaxWidth member is valid.
DDVPD_HEIGHT	The dwMaxHeight member is valid.
DDVPD_ID	The dwVideoPortID member is valid.
DDVPD_CAPS	The dwCaps member is valid.
DDVPD_FX	The dwFX member is valid.
DDVPD_AUTOFLIP	The dwNumAutoFlipSurfaces member is valid.
DDVPD_ALIGN	The dwAlignVideoPortBoundary, dwAlignVideoPortPrescaleWidth, dwAlignVideoPortCropBoundary, and dwAlignVideoPortCropWidth are valid.

dwMaxWidth

Maximum width of the video port field.

dwMaxVBIWidth

Maximum width of the VBI data.

dwMaxHeight

Maximum height of the video port field.

dwVideoPortID

Zero based index identifying the video port.

dwCaps

Video port capabilities.

DDVPCAPS_AUTOFLIP	Flip can be performed automatically to avoid tearing when a VREF occurs. If the data is being interleaved in memory, it will flip on every other VREF.
DDVPCAPS_INTERLACED	Supports interlaced video.
DDVPCAPS_NONINTERLACED	Supports non-interlaced video.
DDVPCAPS_READBACKFIELD	Supports the IDirectDrawVideoPort::GetFieldPolarity method.
DDVPCAPS_READBACKLINE	Supports the IDirectDrawVideoPort::GetVideoLine method.
DDVPCAPS_SHAREABLE	Supports two genlocked video streams that share the video port, where one stream uses the even fields and the other uses the odd fields. Separate parameters (including address, scaling, cropping, etc.) are maintained for both fields.
DDVPCAPS_SKIPEVENFIELDS	Even fields of video can be automatically discarded.
DDVPCAPS_SKIPODDFIELDS	Odd fields of video can be automatically discarded.
DDVPCAPS_SYNCMASTER	Can drive the graphics sync (refresh rate) based on the video port sync.
DDVPCAPS_SYSTEMMEMORY	Capable of writing to surfaces created in system memory.
DDVPCAPS_VBISURFACE	Data within the VBI can be written to a different surface.
DDVPCAPS_COLORCONTROL	Can perform color control operations on incoming data before writing to the frame buffer.
DDVPCAPS_OVERSAMPLEDVBI	Can accept VBI data in a different format or width than the regular video data.
DDVPCAPS_VBIANDVIDEOINDEPENDENT	Indicates that the VBI and video portions of the video stream can be controlled by independent processes.

dwFX

Additional video port capabilities.

DDVPFX_CROPTOPDATA	Limited cropping is available to crop VBI data.
DDVPFX_CROPX	Incoming data can be cropped in the x direction before it is written to the surface.
DDVPFX_CROPY	Incoming data can be cropped in the y direction before it is written to the surface.
DDVPFX_INTERLEAVE	Supports interleaving interlaced fields in memory.
DDVPFX_MIRRORLEFTRIGHT	Supports mirroring left to right as the video data is written into the frame buffer.
DDVPFX_MIRRORUPDOWN	Supports mirroring top to bottom as the video data is written into the frame buffer.
DDVPFX_PRESHRINKX	Data can be arbitrarily shrunk in the x direction before it is written to the surface.
DDVPFX_PRESHRINKY	Data can be arbitrarily shrunk in the y direction before it is written to the surface.
DDVPFX_PRESHRINKXB	Data can be binary shrunk (1/2, 1/4, 1/8, etc.) in the x direction before it is written to the surface.
DDVPFX_PRESHRINKYB	Data can be binary shrunk (1/2, 1/4, 1/8, etc.) in the y direction before it is written to the surface.
DDVPCAPS_PRESHRINKXS	Data can be shrunk in the x direction by increments of 1/x, where x is specified in the dwShrinkXStep member.
DDVPCAPS_PRESHRINKYS	Data can be shrunk in the y direction by increments of 1/y, where y is specified in the dwShrinkYStep
DDVPFX_PRESTRETCHX	Data can be arbitrarily stretched in the x direction before it is written to the surface.
DDVPFX_PRESTRETCHY	Data can be arbitrarily stretched in the y direction before it is written to the surface.
DDVPFX_PRESTRETCHXN	Data can be integer stretched in the x direction before it is written to the surface. (1x, 2x, 3x, etc.)
DDVPFX_PRESTRETCHYN	Data can be integer stretched in the y direction before it is written to the surface. (1x, 2x, 3x, etc.)
DDVPFX_VBICONVERT	Data within the VBI can be converted independently of the remaining video data.
DDVPFX_VBINOINTERLEAVE	Interleaving can be disabled for data within the VBI.
DDVPFX_VBINOSCALE	Scaling can be disabled for data within the VBI.
DDVPFX_IGNOREVBIXCROP	The video port can ignore the left and right cropping coordinates when cropping oversampled VBI data.

dwNumAutoFlipSurfaces

Number of autoflippable surfaces supported by the video port.

dwAlignVideoPortBoundary

Byte restriction of placement within the surface.

dwAlignVideoPortPrescaleWidth

Byte restriction of width after prescaling.

dwAlignVideoPortCropBoundary

Byte restriction of left cropping.

dwAlignVideoPortCropWidth

Byte restriction of cropping width.

dwPreshrinkXStep

Width can be shrunk in the x direction in steps of 1/dwPreshrinkXStep.

dwPreshrinkYStep

Height can be shrunk in the y direction in steps of 1/dwPreshrinkYStep.

dwNumVBIAutoFlipSurfaces

Number of autoflipping surfaces capable of receiving data transmitted during the vertical blanking interval (VBI) independent from the remainder of the video stream. When constructing the autoflip chain, the number of VBI surfaces must equal the number of surfaces receiving the remainder of the video data.

dwReserved1 and dwReserved2

Reserved; set to zero.

QuickInfo

  Windows NT: Use version 5.0 or later.
  Windows: Use Windows 95 or later. Available as a redistributable for Windows 95.
  Windows CE: Unsupported.
  Header: Declared in dvp.h.