This gives you a pretty good idea of what the movie Hitchcock is about:

Just my own note on this: making stuff about Alma and Hitchcock works to create a more dramatic picture but beware of filling in what you don’t know about people. This is a fictional account of their relationship. The only thing people know for sure is that she worked closely with him during their entire relationship. She wasn’t acknowledged, that’s also true. But beyond that…think of it as “just a movie” and you will enjoy it more than quibbling with the facts.