It is not possible to read a film. Everything, thus defined, acquired eluctability. To this tendency one of the founders of historicism, Benedetto Croce, said no a century ago. Signs are found in prose-the impoverished pseudo language of convention, the language of science. Conventions have nothing to do with art, directly.
Art is authentic, original, individual.
Conventions are collective-what everyone already knows. Thus studying genres means paying attention to the prose of a work, not its poetry. For prose is poetry's antithesis. One deals with the individual, the other with the general. The former is an artistic activity, the latter scientific.