Stutter in Full hd video playback

Hi, my z3 tab has some problem in the playback of 1080p movies (mkv or mp4), i want specify that it is an issue that someone can not notice, for example my wife see movies witout problem, but i ham more accurate and see that video is not perfect fluid. I have the last version of lollipop and i have tray thestandard player and vlc and bs player, but have same performance in all. Any sudgestion? Thx

Best device for best battery life for audio playback..?

Hello, dunno what's the longest estimatated playback time for an android photo (probably 15-20hours..) but for apple devices, it's now 50hours or even 80hours depending on the iphone model.. Quite crazy!! Why can't android improve that part..? Anyways, please tell me which is currently best for that.