Big movie files to 1 dvdr

i have got two large avi files both about 750mb and i want to convert and copy them to one dvdr to play as a dvd movie in my dvd player i tried using nerovision with the dvd plugin but when i load the files in it caculates how much of the disc will be used, both these together caculate to about 5gb is ther anything that can shrink the files but still play as a dvd movie :confused: