I've been trying to convert several of my blu-ray discs to mp4 to use with my Apple TVs. I've been using MakeMKV to rip the discs. The mkv files play fine in VLC but when I use Handbrake to convert them, the resulting mp4 file is unplayable. Any suggestions as to what could be going wrong? FYI - I'm using a windows 7 machine with the above mentioned software to rip and convert the blu-ray discs.