Some video players, like VLC and QuickTime Player, will act on that rotation data to show the video correctly on computers. Recent smartphones will embed the rotation information into the video file. (Using free video editors, like Windows Movie Maker or Mac OS X iMovie, to rotate videos will result in such travesties.) Portrait videos were usually shoehorned into a widescreen frame, resulting in ugly black bars on the left and right. Have you ever taken a vertical portrait video using your iPhone, import it to your computer, find that Windows Media Player will play it horizontally, and gotten a neck crick from holding your head sideways? Since the beginning, vertical portrait videos (tall and skinny) have been unwanted and unsupported, living in the shadow of the horizontal landscape videos (short and wide).
