What Resolution/Borders Should i use?

[ArcticFox]

Sorry for this, couldnt find anything for my specific values, and i dont understand all this aspect ratio stuff, so sorry if its been answerered. BUT.....

My XviD Movie has a resolution of 640x272 (its NTSC if that helps), now i want to convert to either VCD or SVCD, when i do this the movie always looks stretched and horrible, i was wondering what borders do i need to add to it so it doesnt come out stretched after i encode it,

Avisynth values if thats at all possible. Thanks

[hakko504]

SVCD 4:3 :LanczosResize(480,272).Addborder(0,96,0,112)

SVCD 16:9 :crop(4,0,-4,0).LanczosResize(480,368).Addborder(0,48,0,64)

VCD 4:3 :crop(18,0,-18,0).LanczosResize(352,144).Addborder(0,48,0,48)

VCD 16:9 :crop(18,0,-18,0).LanczosResize(352,192).Addborder(0,16,0,32)

SVCD resolution is 480x480
VCD resolution is 352x240
16:9 modes are NOT supported by most DVD-standalones, but if you have a TV where you can change input aspect ratio manually then I recommend that you use that. More active pixels => better quality as mpeg1/2 will waste some bits on the black areas. And by aligning the black borders to mod-16 the sharp edges between the black and the picture will use as little overhead as possible. I have also taken the liberty of maximizing the viewing area by cropping some of the edges in order to acheive mod-16 resolution, and I have chosen to shift the picture UP when the addborder command was given uneven values.

Negative crop values are only supported in newer versions of Avisynth, so if you haven't installed v 2.07 yet, then now is the time to do so.