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DWM_PRESENT_PARAMETERS structure (dwmapi.h)

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Specifies Desktop Window Manager (DWM) video frame parameters for frame composition. Used by the DwmSetPresentParameters function.

Syntax

typedef struct _DWM_PRESENT_PARAMETERS {
  UINT32                    cbSize;
  BOOL                      fQueue;
  DWM_FRAME_COUNT           cRefreshStart;
  UINT                      cBuffer;
  BOOL                      fUseSourceRate;
  UNSIGNED_RATIO            rateSource;
  UINT                      cRefreshesPerFrame;
  DWM_SOURCE_FRAME_SAMPLING eSampling;
} DWM_PRESENT_PARAMETERS;

Members

cbSize

The size of the DWM_PRESENT_PARAMETERS structure.

fQueue

TRUE if the caller is requesting queued presents; otherwise, FALSE. If TRUE, the remaining parameters must be specified. If FALSE, queued presentation is disabled for this window and present behavior returns to the default behavior.

cRefreshStart

A ULONGLONG value that provides the refresh number that the next presented frame should begin to display.

cBuffer

The number of frames the application is instructing DWM to queue. The valid range is 2-8.

fUseSourceRate

TRUE if the application wants DWM to schedule presentation based on source rate. FALSE if the application will decide how many refreshes to display for each frame. If TRUE, rateSource must be specified. If FALSE, cRefreshesPerFrame must be specified.

rateSource

The rate, in frames per second, of the source material being displayed.

cRefreshesPerFrame

The number of monitor refreshes through which each frame should be displayed on the screen.

eSampling

The frame sampling type to use for composition.

Remarks

The rateSource member is expressed as a ratio so that content (like that using NTSC standards, which has a rate of 60000/1001) can be accurately expressed. DWM determines how long to display each frame by resampling between the source rate and the composition rate in use each time the desktop is composed.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header dwmapi.h