I have an iPad 4 and decided to put a couple of movies on it using Handbrake...I used the default settings and selected iPad. I already had a couple of movies backed on my computer as ISO files so I used that as my source. Anyway Handbrake worked great but I'm curious why one movie ended up as a m4v file and the other as a mp4 file when the conversion settings were the same? Both played fine on my iPad 4 so would they both play on a iPad 3 or Mini also? Noticed in Handbrake that there was a separate setting for iPad and Apple TV 1,2,3 does that mean a movie converted using the iPad setting wouldn't play on Apple TV?