psp video options video scale size,aspect and video codec?

I am converting a video to a psp and i have the options of turning it to a certain scale size I want the video to be full screen like it takes up the whole screen of the psp. here are the options...
176:120
240:176
320:176
320:240
368:208
384:160
400:192
416:176
480:160
480:270
It also says video aspect i want it to take up the whol screen but not over or bigger then it so here are the options.....
2:1
3:1
3:2
4:3
12:5
16:9
Also it says codec here are the options
DivX
XviD
MPEG-4
H.264/AVC
thats the end so please i want my video to be the full screen of the psp. I have a black psp.