remove motion blur with space time processing

hi everyone

i am working on *removing motion blur with space time proceesing*** please help me how can i know how many frames are there in the video i am working on,and the video is avi format,i know this may be a stupid basic question but please help me because this is first time i am working on matlab

     motion blur can be removed by increasing the exposure time (logically its not exposure time that is to be increased but we should decrease frame interval)
.to do that an intermideate frame is to be introduced so that frame interval is decreased..this is what i have to do....can any one please guide me to write code on this..

little help would be appreciated and would be very usefull

thankyou