1. Open the movie in QT Pro.
Movie -> Get Movie Properties
select video track from left pop-up menu
choose Mask from right pop-up menu
2. Open a new file in a graphics program, like GraphicConverter
or Photoshop
Create a black rectangle with the same pixel dimensions
as the movie
Make a white border on the edges where you want the video
cropped (the white areas will be eliminated)
[OR, to line things up better, click the video image in
QT Pro, copy, then paste it into the graphics program.
Create a new layer to make the mask.]
3. Save the graphics file as GIF.
4. In QT Pro, click Set button and select the GIF file. It should now be cropped.