Posted whenever the natural size (that is, the original dimensions of the movie when it was authored) changes, either because the movie was edited or because new information about the movie was loaded asynchronously.
All clients that display movies using dimensions based on the QTMovieNaturalSizeAttribute should respond to this notification to update their display as necessary.
Available in .3 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)