On a second check into this, there is some corrections to my previous comment:

  A “covered work” means either the unmodified Program or a
  work based on the Program. - GPL

So what a covered work is, is clearly stated. Either unmodified program, or a work based on it.

You are right that a movie don't become a derivative work of any preexisting work it includes. Rather, the movie requires to have performance and "sync" rights to such works or they become legally liable for infringement.

So the real question is, do the GPL give performance and sync permission to the movie producer for using the covered work?

  This License explicitly affirms your unlimited permission to run the 
  unmodified Program. The output from running a covered work is covered by this
  License only if the output, given its content, constitutes a covered work.

The answer to that is ... only if the movie itself is based upon the code and thus become a covered work. Otherwise, the license to do not give any such permission. It could be argued that performance right is covered under the term "convey", as it states:

  "To “convey” a work means any kind of propagation that enables other parties
  to make or receive copies.".

However, it also says:

  "Conveying under any other circumstances is permitted solely under the conditions
  stated below."

Since performance and synchronization are not include below, such right can not be seen as given under the term of conveying.

So to correct my statement: The GPL can't come into effect since it is not giving any permission to the movie producer in the first place. The movie producer would have to get a separate license or be liable under copyright. You are right however that movies do not become derivative works of the preexisting works they incorporate.

For more details about sync rights: http://www.musiclawupdates.com/?p=2182