Movie will not play, mp4

These are all movies for my kids, so all cartoons. The original file size is about 20gb for a typical bluray. At an rf of 22, recommended for bluray, handbrake will output a file that is between 2 and 3.5 gb. A little large for the ipad, but small enough to move around thou my gb network. Except to the hub which maxes out at about 9mb/s write. Hard drives are getting so cheap that I really should just use the original Mkv, but I honestly cannot tell the difference on the 40" LCD that the hub is connected to or on my epson 5010 which is fed by xbmc onto a 110" screen. For the ipad ill usually just use the DVD to get a file that is about 1gb, although I have compressed a few movies even more.
E