Widescreen movie on a Fullscreen TV?

Question

how can a widescreen movie with dimensions like 720 x 384

play on a SDTV which only supports 640 x 480, or am i mistaken by the dimensions of the widescreen movie (these are the dimensions that are given to me on my computer which doesn't distort the image)

Answer 1

Widescreen movies play on standard screens by scaling down so that the width fills the screen, leaving black bars at top and bottom.  A standard 4:3 NTSC picture is 640x480.  For widescreen movies, the picture is squeezed sideways to fit into the 4:3 format.  If played back on a 4:3 screen without modification, the picture will look "squished"  (objects look thin and tall).  When expanded to fit a wide screen TV, the object will look normal.  However, to fit on a 4:3 screen, the height of the picture is reduced to make the objects look normal, producing the black bars top and bottom.  This is called "letterboxing"  Unfortunately, you lose both vertical and horizontal resolution this way.