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;           
    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 the structure is used.

dwFlags

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

DDVPD_AUTOFLIP

The dwNumAutoFlipSurfaces member is valid.

DDVPD_ALIGN

The dwAlignVideoPortBoundary, dwAlignVideoPortPrescaleWidth, dwAlignVideoPortCropBoundary, and dwAlignVideoPortCropWidth 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

The following 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 flips 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 noninterlaced video.

DDVPCAPS_OVERSAMPLEDVBI

Accepts VBI data in a different format or width than 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; one stream uses the even fields, and the other uses the odd fields. Separate parameters (including address, scaling, cropping, and so on) are maintained for each field.

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 refresh rate, based on the video port sync.

DDVPCAPS_SYSTEMMEMORY

Can write to surfaces created in system memory.

DDVPCAPS_VBIANDVIDEOINDEPENDENT

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

The following 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_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, and so on) in the x-direction before it is written to the surface.

DDVPFX_PRESHRINKYB

Data can be binary shrunk (1/2, 1/4, 1/8, and so on) 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, and so forth)

DDVPFX_PRESTRETCHYN

Data can be integer stretched in the y-direction before it is written to the surface. (1x, 2x, 3x, and so forth)

DDVPFX_VBICONVERT

Data within the VBI can be converted, independent 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 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

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

dwNumPreferredAutoflip

Optimal number of autoflippable surfaces supported by the hardware.

wNumFilterTapsX and wNumFilterTapsY

Number of taps that the prescaler filter uses in the x- and y-directions. The value of 0 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

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dvp.h.