If you have an Apple TV, you can watch videos in your iTunes library on your home theater system.
These videos must be compatible with Apple TV. If you drag a video file from the Finder to the iTunes window and the video doesn’t appear in iTunes, it isn’t compatible. In some cases, you can save video files in a different format so that they work with iTunes.
Any video that plays on iPod, iPhone, or iPad is compatible with Apple TV.
Here are ways to save a version of a video to work with iTunes and Apple TV:
Select the movie in iTunes, and choose Advanced > Create Apple TV Video.
In iMovie, you can save your movie as a QuickTime movie or export it directly to your iTunes library. Choose Share > iTunes, click Apple TV, and click Publish. (For more information, see iMovie Help.)
If you have QuickTime Pro, open your movie in QuickTime Player and choose File > Export > “Movie to Apple TV.” For more information, see QuickTime Player Help.
For more information, see the Apple TV user’s guide at the Apple TV Support website.