batch reencoding level 5 to level 4.2 mkv

how do I batch re-ncode level 5 mkv to level 4.2 the easy way?

I was playing 1080p animes in my ps3 using showtime but I got no video only audio and subtitles. It seems it can only play level 4.2:(

I get this error in showtime ps3
"cell-h264 forcing level 4.2 for content in level 5.0. this may break video playback"