I read a request awhile back asking if VLC could change the color of a letterboxed video to be of a different color (Black to White or Grey). The response was that VLC may not be handling the letterbox borders.
My idea is that VLC can input the borders based upon the aspect ratio of the video. For instance: Video aspect ratio is 16:9 (in a 4:3 frame). VLC adds 80 pixels at the top and 80 pixels at the bottom over the video window, and they’ll be of the color that the user chooses (black, white, grey, ect).
The user can also customize the amount of pixels added for borders manually, like a DVD with a 221:100 aspect ratio, and choose them through the menu at any time.
Anyway…ah…um…think about it?