Answer: letterbox

AnswerCrossword Clue
LETTERBOXDVD format
LETTERBOXFormat for some DVDs
LETTERBOXTV screen format
letterboxtechnique for displaying a wide-screen film on a regular-format television screen by reducing its size until the entire image is visible, thus retaining the aspect ratio, with black bands filling the borders of the screen above and below the picture
letterboxa box for holding letters