I have few mkv files what are lagging while playing. In VLC after a while after lot of glitch and pixels goes haywire and screen freeze but audio goes well. in MPC player video runs smooth after a while video and audio goes in slow motion and audio comes after pause all time. but BUT this happens after few minutes all time. and see duration and close it and after sometime open it it works smooth for few minutes on duration when this happened. but after a while same things happens. tired of googling didn't find answer. so here I am