This method provides notification that the window's visible region has changed. It is essential that any overlay hardware be updated to reflect the change to the visible region before returning from this method.

HRESULT OnClipChange(
  RECT* pSourceRect,
  RECT* pDestinationRect,
  RGNDATA* pRgnData


  • pSourceRect
    [in] Region of the video to use.
  • pDestinationRect
    [in] Video destination.
  • pRgnData
    [in] Clipping information.

Return Values

Returns an HRESULT value that depends on the implementation. HRESULT can be one of the following standard constants, or other values not listed.

Value Description
E_FAIL Failure.
E_POINTER Null pointer argument.
E_INVALIDARG Invalid argument.
E_NOTIMPL Method is not supported.
S_OK or NOERROR Success.


The calls to OnClipChange happen in synchronization with the window. It is called with an empty clip list to freeze the video before the window moves, and then called again when the window has stabilized with the new clip list.

If the window rectangle is all zeros, the window is invisible. The filter must take a copy of the information if it needs to store it.


DirectShow applications and DirectShow filters have different include file and link library requirements. See Setting Up the Build Environment for more information.

OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.

See Also

IOverlayNotify Interface

Last updated on Wednesday, April 13, 2005

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