Part 1. What is Plex and Why iTunes Videos Can't be Played on Plex Directly
Quick introduction to Plex
Plex is a client-server media player system which comprised of two parts Plex Media Server and Plex Media Player.
Plex Media Server is a media managing software which can be downloaded to computers like Windows, MacOS, LInux , NAS, Wifi routers or just runs on Plex cloud. By settings up the server, it can add the videos from your library and make they accessible by other devices within the same Plex account.
Plex Media Player is also known as the Plex App. It supports Android, Windows, IOS phones, Sonos, Chromecast, Nvidia Shield, Xbox One, Smart TV, Amazon Alexa and etc. And it can help you play the local media file under a free account and stream the videos which you have added to the Plex Media Server under a premium subscription membership.
Why iTunes videos can't be played on Plex
Plex is powerful for almost all kinds of contents, but it can't access the iTunes videos. The reason is obvious for everyone, it is because the iTunes videos are locked by the digital rights managements. Apple don't want their digital media files to be copied or shared out of their own ecosystem. With this DRM protection, even for the Apple devices including Mac computers, IOS mobile devices, you are required to authorize the videos before you can play, let alone other non-Apple devices. In addition, there is not a sign that when this DRM mechanism would be changed or removed by Apple itself, so the videos are likely to be locked with this DRM decryption in the foreseeable time.