 Important: |
|---|
| This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist. |
The DDVIDEOPORTBANDWIDTHstructure describes the bandwidth characteristics of an overlay surface when used with a particular video port and pixel format configuration. This structure is used with the IDirectDrawVideoPort::GetBandwidthInfomethod.
typedef struct _DDVIDEOPORTBANDWIDTH {
DWORD
dwSize
;
DWORD
dwCaps
;
DWORD
dwOverlay
;
DWORD
dwColorkey
;
DWORD
dwYInterpolate
;
DWORD
dwYInterpAndColorkey
;
DWORD
dwReserved1
;
DWORD
dwReserved2
;
} DDVIDEOPORTBANDWIDTH,*LPDDVIDEOPORTBANDWIDTH;
Members
- dwSize
- Size of this structure, in bytes. This member must be initialized before use.
- dwCaps
- Flag values specifying device dependency. This member can be
one of the following values:
DDVPBCAPS_DESTINATION This device's capabilities are described in terms of the overlay's minimum stretch factor. Bandwidth information provided for this device refers to the destination overlay size. DDVPBCAPS_SOURCE This device's capabilities are described in terms of the required source overlay size. Bandwidth information provided for this device refers to the source overlay size. - dwOverlay
- Stretch factor or overlay source size at which an overlay is supported multiplied by 1000. For example, 1.3 = 1300, or 0.75 = 750.
- dwColorkey
- Stretch factor or overlay source size at which an overlay with color keying is supported multiplied by 1000. For example, 1.3 (1300), or 0.75 (750).
- dwYInterpolate
- Stretch factor or overlay source size at which an overlay with y-axis interpolation is supported multiplied by 1000. For example, 1.3 (1300), or 0.75 (750).
- dwYInterpAndColorkey
- Stretch factor or overlay source size at which an overlay with y-axis interpolation and color keying is supported multiplied by 1000. For example, 1.3 (1300), or 0.75 (750).
- dwReserved1and dwReserved2
- Reserved; set to zero.
Remarks
When DDVPBCAPS_DESTINATION is specified, the stretch factors described in the other members describe the minimum stretch factor required to display an overlay with the dimensions given when calling the GetBandwidthInfomethod. Stretch factor values under 1000 mean that the video port is capable of shrinking an overlay when displayed, and values over 1000 mean that the overlay must be stretched larger than their source to be displayed.
When DDVPBCAPS_SOURCE is specified, the stretch factors described in the other members describe how much you must shrink the overlay source so it can be displayed. In this case, the best possible value is 1000, meaning that no shrinking is required. Smaller values tell you that the source rectangle you specified when calling GetBandwidthInfowas too large. For example, if the stretch factor is 750 and you specified 320 pixels for the dwWidthparameter, then you will not be able to display the overlay at that size. To display the overlay successfully, you must use a source rectangle 240 pixels wide.
Requirements
Runs on Versions Declared in Windows CE OS 2.12 or later. Version 2.12 requires DXPAK 1.0 or later. dvp.h