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Choosing the Position Where a Movie is Pasted

Q When a user pastes a movie into a movie controller movie, the added movie is inserted in the top left corner of the movie. Is there a way for the user to choose the position where the movie is pasted? If not, how can I give the movie controller or Movie Toolbox an offset to use rather than have the editing operations use the top left corner?

A When you paste a movie into a movie-controller movie, the movie controller calls PasteMovieSelection to insert the source movie. Since all the characteristics of the movie are inserted, the pasted movie is inserted in the top left corner of the movie-controller movie. There's no easy way to specify an offset directly to the movie controller. If you need to change the offset of the pasted movie, you have to modify the movie yourself after the paste using Movie Toolbox commands. Once you're done changing the movie, be sure to call MCMovieChanged so that the movie controller updates correctly.

The actual modification is simple: call GetTrackMatrix, add your offset to the matrix, and call SetTrackMatrix. The only difficulty is in determining which tracks to modify, since the paste may either create a new track or use an existing one. We recommend doing this by gathering all track IDs before the paste, and then comparing them with the track IDs after the paste. Since most movies these days have just a few tracks, this shouldn't require much overhead, but be warned -- some movies do have a lot of tracks! To get the track information, call GetMovieTrackCount and GetMovieIndTrack.

Here's one last idea: If you don't mind changing the source movie, offset the source movie before the paste as an alternative method.

[May 01 1995]

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