IDirectDrawVideoPort::GetBandwidthInfo

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The IDirectDrawVideoPort::GetBandwidthInfomethod retrieves the minimum required overlay zoom factors and device limitations of a video port that uses the provided output pixel format.

HRESULT GetBandwidthInfo(
LPDDPIXELFORMAT
lpddpfFormat
,
DWORD
dwWidth
,
DWORD
dwHeight
,
DWORD
dwFlags
,
LPDDVIDEOPORTBANDWIDTH
lpBandwidth
);

Parameters

lpddpfFormat

Address of a DDPIXELFORMATstructure that describes the output pixel format for which bandwidth information will be retrieved.

dwWidthand dwHeight

Dimensions of an overlay or video data. The interpretation of these parameters depends on the value specified in the dwFlagsparameter.

dwFlags

Flags indicating how the method is to interpret the dwWidthand dwHeightparameters. This parameter can be one of the following values:

DDVPB_OVERLAY	The dwWidthand dwHeightparameters indicate the size of the source overlay surface. Use this flag when the video port depends on the overlay source size.
DDVPB_TYPE	The dwWidthand dwHeightparameters are not set. The method will retrieve the device's dependency type in the dwCapsmember of the associated DDVIDEOPORTBANDWIDTHstructure. Use this flag the first time you call this method.
DDVPB_VIDEOPORT	The dwWidthand dwHeightparameters indicate the prescale size of the video data that the video port writes to the frame buffer. Use this flag when the video port depends on the overlay zoom factor.

lpBandwidth

Address of a DDVIDEOPORTBANDWIDTHstructure that will be filled with the retrieved bandwidth and device dependency information.

Return Values

If the method succeeds, the return value is DD_OK.

If the method fails, the return value may be one of the following error values:

DDERR_INVALIDOBJECT

DDERR_INVALIDPARAMS

Remarks

This method will usually be called twice. When you make the first call, specify the DDVPB_TYPE flag in the dwFlagsparameter to retrieve information about the device's overlay dependency type. Subsequent calls using the DDVPB_VIDEOPORT or DDVPB_OVERLAY flags must be interpreted considering the device's dependency type.

Requirements

Runs on	Versions	Declared in	Link to
Windows CE OS	2.12 or later. Version 2.12 requires DXPAK 1.0 or later.	dvp.h	ddraw.lib