Q: shutdown issue !!

i'm using macbook air mid 2013.

i was watching a movie on quicktime player, the default player. and it just stucked!! hanged.

all other apps and mac working perfect, but the application is not closing/quitting, and not letting the system to shutdown or restart. for last 7,8 days i'm unable to shutdown my mac beacuse the application is not leting it shutdown.

i have hold the powwer button for more than 2,3 min still no use.

plz advice !!

looking forward for positive responce.