How much of a difference is there between a video purchased or rented using iTunes, and the standard-definition version rentable on your Apple TV? After a week of comparison downloads, cross-checks, and cracking open an Apple TV, the answer is: “none.”
Discussed in detail in our just-published Complete Guide to iTunes Movie Rentals, Part 2, users will see no benefit from using the Apple TV to rent standard-definition movies already available in iTunes, as both files offer the same bit rates, file sizes, and sub-DVD-quality resolutions. In fact, using an Apple TV to rent a standard-definition movie places you at a disadvantage: you can’t transfer an Apple TV-rented movie to your iPod, iPhone, or iTunes library, even though the same movie rented through iTunes can be transferred to any of the other devices.
Notably, however, Apple has started to make interesting changes to standard-definition videos rented and sold through the iTunes Store. New releases, and some previously-released titles, are now anamorphically encoded to take better advantage of the 480 pixels of resolution supported by all of Apple’s portable video devices. As a result, though new videos are still not true DVD-quality, many offer superior vertical resolution to the 272- and 352-pixel movies sold by Apple last year. This change, discovered through comparisons between files downloaded last year and this past week, explains ambiguities that have existed since January 2008 as to whether iTunes Store movie rentals would be true DVD-quality, or still fall short.