Letterbox or Add Borders??

[dvdaddict]

Hello, I was looking through the avisynth html 2.04 and noticed letterbox in the scripting. I normally use addborders. Is one better than the other? or does it matter which is used. Most of my stuff is SVCD Encoding. Thanks

[sh0dan]

Letterbox blacks out some of the video area - it does not change the size of the video, as addborders does.