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IAMVideoTransform::GetScalingCaps

  • Article

4/8/2010

Retrieves the scaling capabilities of the current filter graph.

Syntax

HRESULT GetScalingCaps(
     BOOL bDirectDraw
     DWORD *pdwScalingCapsMask
     AMScalingRatio **ppRatios
     ULONG *pCount
  );

Parameters

  • bDirectDraw
    [in] Specifies where the scaling capability information will be retrieved. If true, the information will be retrieved from the DirectDraw video driver, otherwise it will be from an upstream filter or DMO, if one exists.
  • *pdwScalingCapsMask
    [out] Represents the scaling capabilities of the requested filter graph. The value of this parameter should be either AM_TRANSFORM_SCALING_LIMITED or AM_TRANSFORM_SCALING_ARBITRARY.
  • **ppRatios
    [out] If pdwScalingCapsMask is set to AM_TRANSFORM_SCALING_LIMITED, this parameter contains the array of ratios that is allowed. If pdwScalingCapsMask is set to AM_TRANSFORM_SCALING_ARBITRARY, this parameter contains the minimum and maximum allowed ratios. If no minimum or maximum is specified, this parameter should contain NULL.
  • *pCount
    [out] Specifies the number of elements present in the ppRatios array.

Return Value

Returns an HRESULT value that depends on the implementation of the interface.

In the current DirectShow implementation, this method returns NOERROR if successful, or E_INVALIDARG or E_FAIL upon failure.