VMRALPHABITMAP Structure
| Microsoft DirectShow 9.0 |
VMRALPHABITMAP Structure
This topic applies to Windows XP or later.
The VMRALPHABITMAP structure is used in the VMR-7 filter's IVMRMixerBitmap methods when the application is providing a static alpha-blended bitmap to be displayed on the composited video frame.
Syntax
Members
dwFlags
Flags that instruct the mixer where to find the bitmap. The following values are defined.
| Value | Description |
| VMRBITMAP_DISABLE (0x00000001) | Disable the bitmap for now. |
| VMRBITMAP_HDC (0x00000002) | Obtain the bitmap from the HDC. |
| VMRBITMAP_ENTIREDDS (0x00000004) | Take the entire DirectDraw surface. When this flag is specified, rSrc is ignored. |
| VMRBITMAP_SRCCOLORKEY (0x00000008) | The clrSrcKey value is valid and should be used when blending. |
| VMRBITMAP_SRCRECT (0x00000010) | Indicates that the rSrc rectangle is valid and specifies a sub-rectangle of the original app image to be blended. Use of this parameter enables "Image Strips." This flag is only valid on UpdateAlphaBitmapParameters. When the VMRALPHABITMAP struct is specified in SetAlphaBitmap, rSrc must refer to the entire bitmap. |
hdc
Specifies the handle to the device context for the bitmap. Specify NULL if the bitmap is located in a DirectDraw surface.
pDDS
Pointer to a DirectDraw surface that contains the bitmap. Specify NULL if the bitmap is to be obtained from a GDI device context.
rSrc
Specifies the source rectangle in either the GDI device context or the DirectDraw surface.
rDest
Specifies the destination rectangle in composition space.
fAlpha
Specifies the alpha blending value; must be a value from 0.0 to 1.0 (inclusive).
clrSrcKey
Specifies the source color key.
Requirements
Header: Dshow.h. Requires Microsoft Windows XP.
See Also