Instructor unable to play HD video purchased from iTunes
An instructor has their laptop connected to a projector in a classroom, and tried to play an HD video that they purchased in iTunes. iTunes displays an error saying it cannot play the video.
The video purchased in iTunes is subject to HDCP – High-bandwidth Digital Content Protection. Basically it’s an encrypted signal to prevent copying, and every piece of of equipment in the signal chain must support HDCP for it to work. If iTunes and the OS detect that you are using a non-digital (eg. VGA connection) or non-compatible equipment, it won’t play the video.
This KB article explains more: support.apple.com/kb/ts3354
Download the SD version
Although HD is usually downloaded first, the individual should be able to look back at their purchase history and download the SD version. Instructions on accessing your purchase history: support.apple.com/kb/HT2727
Similarly, a DVD-ripped copy will also be playable.
Purchase an HD Fury dongle
While expensive ($250+), this piece of equipment will convert a digital signal into analog (HDMI to VGA) and allow the video to play. It simply needs to be connected between the computer and the video cable.
Upgrade your room
Buy new equipment and redesign your space to be all-digital so that all pieces of the signal chain support HDCP.