|Microsoft DirectShow 9.0|
Indicates whether the object has changed since it was last saved to its current stream.
Returns S_OK if the filter needs saving and S_FALSE if it does not need saving.
This member function implements the IPersistStream::IsDirty method.
** Header:** Declared in Pstream.h; include Streams.h.
** Library:** Use Strmbase.lib (retail builds) or Strmbasd.lib (debug builds).