DDVIDEOPORTCAPS

  • 项目

This 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;
  DWORD dwFlags;
  DWORD dwMaxWidth;
  DWORD dwMaxVBIWidth;
  DWORD dwMaxHeight;
  DWORD dwVideoPortID;
  DWORD dwCaps;
  DWORD dwFX;
  DWORD dwNumAutoFlipSurfaces;
  DWORD dwAlignVideoPortBoundary;
  DWORD dwAlignVideoPortPrescaleWidth;
  DWORD dwAlignVideoPortCropBoundary;
  DWORD dwAlignVideoPortCropWidth;
  DWORD dwPreshrinkXStep;
  DWORD dwPreshrinkYStep;
  DWORD dwNumVBIAutoFlipSurfaces;
  DWORD dwNumPreferredAutoflip;
  WORD  wNumFilterTapsX;
  WORD  wNumFilterTapsY;
} 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 table shows the possible flags.
    Flag Description
    DDVPD_AUTOFLIP The dwNumAutoFlipSurfaces member is valid.
    DDVPD_ALIGN The dwAlignVideoPortBoundary, dwAlignVideoPortPrescaleWidth, dwAlignVideoPortCropBoundary, and dwAlignVideoPortCropWidth members are valid.
    DDVPD_CAPS The dwCaps member is valid.
    DDVPD_FILTERQUALITY The wNumFilterTapsX and wNumFilterTapsY members are valid.
    DDVPD_FX The dwFX member is valid.
    DDVPD_HEIGHT The dwMaxHeight member is valid.
    DDVPD_ID The dwVideoPortID member is valid.
    DDVPD_PREFERREDAUTOFLIP The dwNumPreferredAutoflip member is valid.
    DDVPD_WIDTH The dwMaxWidth member is 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. The following table shows the possible flags.
    Flag Description
    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_COLORCONTROL Can perform color control operations on incoming data before writing to the frame buffer.
    DDVPCAPS_INTERLACED Supports interlaced video.
    DDVPCAPS_NONINTERLACED Supports non-interlaced video.
    DDVPCAPS_OVERSAMPLEDVBI Can accept VBI data in a different format or width than the regular video data.
    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, and cropping, 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_VBIANDVIDEOINDEPENDENT Indicates that the VBI and video portions of the video stream can be controlled by independent processes.
    DDVPCAPS_VBISURFACE Data within the VBI can be written to a different surface.
  • dwFX
    Additional video port capabilities. The following table shows the possible flags.
    Flag Description
    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_IGNOREVBIXCROP The video port can ignore the left and right cropping coordinates when cropping oversampled VBI data.
    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, ) in the x-direction before it is written to the surface.
    DDVPFX_PRESHRINKYB Data can be binary shrunk (1/2, 1/4, 1/8, ) in the y-direction before it is written to the surface.
    DDVPFX_PRESHRINKXS Data can be shrunk in the x-direction by increments of 1/x, where x is specified in the dwPreshrinkXStep member.
    DDVPFX_PRESHRINKYS Data can be shrunk in the y-direction by increments of 1/y, where y is specified in the dwPreshrinkYStep.
    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, ).
    DDVPFX_PRESTRETCHYN Data can be integer stretched in the y-direction before it is written to the surface (1x, 2x, 3x, ).
    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.
  • dwNumAutoFlipSurfaces
    Maximum number of auto-flippable 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
    Maximum number of auto-flipping surfaces capable of receiving data transmitted during the vertical blanking interval (VBI) independent from the remainder of the video stream. When constructing the auto-flip chain, the number of VBI surfaces must equal the number of surfaces receiving the remainder of the video data.
  • dwNumPreferredAutoflip
    Optimal number of auto-flippable surfaces supported by the hardware.
  • wNumFilterTapsX and wNumFilterTapsY
    Number of taps the prescaler filter uses in the x- and y-directions. The value of zero indicates that no prescaling is performed in that direction, 1 indicates that the prescaler performs replication, 2 indicates that the prescaler uses two taps, and so on.

Requirements

OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
Header: Dvp.h.

 Last updated on Thursday, April 08, 2004

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