● About dividing movies
As shown in Figure 2.6, Saturn format Cinepak movie consists of movie header and movie data (called video + sound, sample data). This header contains the entire movie information and sample information. The sample information is the information for each sound interleaved with the information for each frame of video, and 16 bytes are required for one sample. The movie header size can be calculated by the following formula.

 H = (L × F + 4L−1) × 16 + 80 (Formula 2.2)
H: Header size [bytes]
L: Movie length [seconds]
F: Frame rate [fps] 

For example, if you create a 10-minute movie with 30fps and sound, the header size will be about 320KB.
The header must always exist in memory during movie playback, so if you create a long movie, the movie's header will grow and press on Saturn's work RAM area. Also, if the header is large, reading from the CD-ROM will take time, and movie playback will be delayed. To avoid these problems, divide the movie and perform continuous playback. The Cinepak library can play the divided movie seamlessly and continuously by registering the movie to be played next.