|Microsoft DirectX 9.0|
The Active method notifies the pin that the filter is now active.
virtual HRESULT Active(void);
When the filter goes from stopped to paused, the CBaseFilter class calls this method on all of the filter's connected pins.
This method does nothing in the base class. Derived classes can override this method; for example, a pin might commit allocators or obtain hardware resources.
The filter graph manager's internal state is not updated until after this member function returns, so do not test the state from this method.