Microsoft DirectX 9.0


The SetCallbackInterface method retrieves a pointer to the callback interface of the Overlay Mixer so that the calling application can be notified about adjustments to the display during video playback.


HRESULT SetCallbackInterface(
  IDDrawExclModeVideoCallback *pCallback,
  DWORD dwFlag



[out] Pointer to the object that implements the IDDrawExclModeVideoCallback interface. If pCallback is NULL, the callback interface is set to NULL and no more callbacks are made. If there was a previous callback interface, it is released and no more callbacks are made to it. If pCallback is not NULL and this method returns S_OK, then the reference count of the object pCallback points to is incremented.


[in] Must be zero.

Return Values

Returns an HRESULT value. Possible values include the following.

Return code Description
S_OK Success.
E_INVALIDARG Argument is invalid.


An application should use this method to get notification about the overlay size, position, or color key change happening, so that it can hide or show the video, or adjust the video at the start, end, or during playback. By calling this method, an application can access the IDDrawExclModeVideoCallback interface and pass the pointer to that interface to the Overlay Mixer.

See Also