Yesterday, Apple announced that the iTunes Store was now selling $20 high-definition movies for viewing on a computer, as well as renting computer-ready versions for $4-$5 in the same way that it has been through the Apple TV. In an impressive, though space-consuming feat, Apple provides users with both a high-definition video for computer and Apple TV use, as well as one that’s lower-resolution and capable of being played on your iPod or iPhone. The test video we downloaded, Punisher: War Zone, came in a 3.09GB, 1280×532 file, as well as a DVD-quality 1.15GB, 853×354 version. Unfortunately, the HD version refused to play back from a current-model MacBook through a high-definition external monitor—even an Apple Cinema Display.


If you’re using a relatively new Mac, specifically one with a Mini DisplayPort connector, and trying to play iTunes Store HD movies through any external monitor other than Apple’s recently-released 24” LED Cinema Display, you’re most likely out of luck. Click on the video and iTunes will give you an error message: “This movie cannot be played because a display that is not authorized to play protected movies is connected. Try disconnecting any displays that are not HDCP authorized.” Try again to play it, and the video playback window will appear, completely black, and no audio will be present. But if you try to play the same video on the screen built into your Mac, or on Apple’s LED Cinema Display, it will work just as expected.


The reasons for this error message are simple: Apple has started to support HDCP, “high-bandwidth digital content protection,” an Intel-developed way to stop high-definition videos from being played on older, less secure receiving devices. Virtually all VGA- and DVI connector-equipped external computer monitors sold in the past are non-compliant, so users of Apple’s latest Mini DisplayPort-based Mac computers will need to either watch the HD videos on the screens built into their computers, buy new, HDCP-compliant monitors, or transfer their files to an iTunes-authorized computer without Mini DisplayPort.


That latter option is available because Apple does not appear to enforce HDCP protection on earlier computers. We tested the same HD video on an older, DVI connector-equipped Mac mini with the same prior-generation Cinema Display, and it played without incident—as soon as we installed iTunes 8.1. iTunes 8.0.2 refused to play the HD movie at all, suggesting that iTunes would not authorize the video for that computer.


Even though Apple includes both HD and SD versions of videos when you make an HD movie purchase, iTunes doesn’t currently handle external monitor playback in an especially bright way. The HDCP error message is basically a dead-end, offering no obvious solution or alternative for users who want to watch the videos they’ve just purchased on their external monitors. Thankfully, there is an option. Right click on the movie, and an option will appear in the list of choices: “Version.” By “Default,” iTunes selects HD. But by selecting “Standard Definition (SD),” iTunes will play that movie on an external monitor—at the standard-definition resolution. It doesn’t make the best use of the monitor’s capabilities, but at least users can watch part of what they’ve purchased.


Also note that HDCP isn’t required for all HD videos. High-definition TV shows purchased through the iTunes Store will generally play back on both a computer and an external monitor without a fuss—a reason that users most likely haven’t come across this error message up until now. And homemade HD videos created by high-definition camcorders also play back without any sort of issue.

In any case, iTunes needs to be fixed to deal more appropriately with HDCP-locked content. Assuming that Apple can’t let users play back all the videos they’ve purchased on all their other monitors, the company should warn users conspicuously before purchase that the HD videos may not be viewable on virtually any external display they may own. It should also transform its current error message box to offer an automatic “watch standard-definition version instead” option. Given that the company has been pitching the “MacBook Plus External Monitor” solution for some time now, and also offers desktop machines that will suffer the same blacked out video phenomenon with many external monitors, these simple if not entirely satisfying options will at least save users the hassle of trying to figure out how to watch the videos they’ve just purchased on the monitors they own.