On IMDb website, from the search dropdown menu choose company, and then next to it type the movie studio. It's really not that complicated. To get you started, I found the first three for you.
Universal Pictures [us]
Paramount Pictures [us]
DreamWorks SKG [us]
Gets you what I previously said. And does not mean that company has the Video rights.
Going after video rights gets you a completely different set of numbers. And lots of companies to add up.