“I’ve got a large library of H.264 mp4 videos that I have copy them to an external hard drive, and they all work perfectly in iTunes. I recently got an Apple TV 3, and it was working great until I tried to play an older mp4, one of the originals that I had converted, and the ATV 3 claimed that it couldn’t recognize the file format. What gives?” Although Apple TV support to play MP4 files, you probably have some MP4 files that can’t be read by your Apple TV 3. Is there quick and easy way to resolve this problem? Sure. No matter you are connected via USB, HDMI, Continue reading MP4 won’t display on Apple TV- Converting MP4 to M4V for Apple TV→