Who turns the story into film?

Answer 1

Directors who find stories interesting ask the author for permission, then make a movie.

Another Answer

Although movies are a director's medium, films are financed by producers, who sign the check to purchase rights to a story, hire a screenwriter and director to fashion a script from the story, and then work with the director to hire actors and all the other people involved with making a movie. This process 'turns a story into a film'.