A movie is a succession of images. In MegaWave2, it is implemented as a
chain of images: you may notice that all types of images have the
next(see section 2).
Normally set to NULL, these fields point to the previous image and
to the next image respectively, when the image is part of a movie.
The first image of the movie has a NULL
previous field and the
last image of the movie has a NULL
A movie structure is basically a pointer to the first image. For each image structure corresponds a movie structure.