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DXVA_ConfigAlphaCombine structure (dxva.h)

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The DXVA_ConfigAlphaCombine structure is sent by the host decoder to the accelerator to set the configuration for alpha-blending combination operations.

Syntax

typedef struct _DXVA_ConfigAlphaCombine {
  DXVA_ConfigQueryOrReplyFunc dwFunction;
  DWORD                       dwReservedBits[3];
  BYTE                        bConfigBlendType;
  BYTE                        bConfigPictureResizing;
  BYTE                        bConfigOnlyUsePicDestRectArea;
  BYTE                        bConfigGraphicResizing;
  BYTE                        bConfigWholePlaneAlpha;
} DXVA_ConfigAlphaCombine, *LPDXVA_ConfigAlphaCombine;

Members

dwFunction

Indicates the type of query or response when using probing and locking commands. The most significant 24 bits of dwFunction is the DXVA_ConfigQueryOrReplyFlag variable.

The least significant 4 bits of the DXVA_ConfigQueryOrReplyFlag variable contain status indicators for the query or response being performed.

The least significant 8 bits of dwFunction is the bDXVA_Func variable that, in this case, is equal to 3.

dwReservedBits[3]

Specifies the reserved bits used for packing and alignment. This member must be zero.

bConfigBlendType

Specifies the type of alpha-blend combinations to be performed. Zero indicates front-end buffer-to-buffer blend, and 1 indicates back-end hardware blend.

The preferred value for an accelerator to support is zero.

bConfigPictureResizing

Specifies whether the PictureSourceRect16thPel member of DXVA_BlendCombination for graphic blending may differ in width and height from the PictureDestinationRect member of DXVA_BlendCombination (adjusted for the one-sixteenth sample scaling of PictureSourceRect16thPel). This member also specifies whether the values in PictureSourceRect16thPel are multiples of 16, thus requiring the source picture to be resampled by the accelerator. A value of 1 indicates that resampling (whether for resizing or for subpixel accuracy) is supported; a value of zero indicates that it is not.

bConfigOnlyUsePicDestRectArea

Specifies whether the decoder can perform operations that use values for areas of a destination picture outside the area defined by the PictureDestinationRect member of the DXVA_BlendCombination structure. The value zero indicates that areas outside of PictureDestinationRect can be specified and displayed by the blend combination commands. The value 1 indicates that the decoder cannot rely on the values of, or display, any region of the blended surface outside of the area specified by PictureDestinationRect.

bConfigGraphicResizing

Indicates whether alpha blending is supported in graphic image resizing. A value of 1 indicates that it is; a value of zero indicates that it is not. bConfigGraphicResizing specifies whether the GraphicSourceRect member of DXVA_BlendCombination (for subpicture blending) may differ in size from the GraphicDestinationRect member of DXVA_BlendCombination. If these values are different, the alpha-blending graphic must be resampled by the accelerator.

bConfigWholePlaneAlpha

Specifies whether a whole-plane alpha opacity value can be applied to the graphic image. A value of 1 indicates that a whole-plane alpha can be applied; a value of zero indicates that it cannot.

Requirements

Requirement Value
Header dxva.h (include Dxva.h)

See also

DXVA_BlendCombination