Problems without full screen on dvd players



my stand alone dvd player for my tv does not have full screen mode like my pc has, does anyone have a solution for this ?

The problem is I like to play my family album, which consists of 200
video clips, but they are in all sorts of different resolutions.
Varies between 320x 240 to 720x 560.

I do not want to re-encode all those clips to a one standard resolution because I do not want to loose video quality in those
clips. is there anything I can do so that I do not have to change
tv screen size each time the next clip plays ?

The main problem is that the dvd player only allows zoom by 1.2 , 1.5 , 2.