How can one add a single movie to tMM?

How can one add a single movie to tMM? So when I copy a new movie to the movie folder and I do not want tMM update the entire content but that new movie only, how could I do it?

When one updates the sources / a source and only a single movie is found tMM completely rebuilds the image cache (after scraping that movie) which lasts half an hour or longer. How could one avoid it / make it faster?