How do I find who owns movie rights?



Sorry if this isn't the right forum to ask this, but I don't know
which one is.

Does anyone know how I can find out who owns the rights to a
particular movie or film footage? I thought of renting the movie and
just looking at the credits but no one has it.

Any ideas? Is there a database or something where I can look it up?
I tried imdb.com but all it says is the producer, not the owner of the
film.
.