What are jacket pictures?
A DVD can optionally include a representative still image called a jacket picture, which is displayed by some DVD players when the disc is inserted, paused, or stopped. Some DVD jukeboxes also use jacket pictures for thumbnail lists. A jacket picture is often the same cover art used on the DVD package or sometimes a simplified picture, especially for the smaller sizes. The picture is stored on the disc in the root-level JACKET_P folder as MPEG-2 still images in three sizes —large, medium, and small— in either 1.33 or 1.78 (widescreen) NTSC or PAL format to match the video format of the disc.
