Another aspect of this decision comes from the Java arena. The Cinepak codec seems to be usable everywhere, though, so please try to use that whenever possible. Also, if you make an AVI file instead of a QuickTime file, use the Cinepak codec there, too. See the JMF site for details on supported formats. We do not foresee a huge demand for video in Project Links modules.
Video files are typically quite large and take a relatively long time to download.
If you do use video, try to keep the size down by trimming off unnecessary frames from the beginning and the end. You can also usually get away with reducing the image quality and still have the video be legible.