Structure is a difficult element to consider in a lot of film music because the structure is nearly always defined by what's going on on screen. This often makes the structure of film pieces through-composed because each section is often new and slightly varied. This is a good description of the Star Wars set work from bar 33 (1'16).
That being said, in opening and closing credits composers are often able to use musical structures a bit more. John Williams uses ternary form (ABA) during the main title. The B section provides a nice amount of lyrical contrast, typical of this type of structure:
Introduction - bar 1
A section - bar 4, 0'07
B section - bar 12, 0'26
A section - bar 21, 0'48
From this point onwards the structure becomes through-composed.