A decoder apparatus which includes a de-multiplexer, which is configured to divide motion picture data from a transport stream, a video decoder, which is configured to decode the divided motion picture data, and a first re-formatter on-screen unit, which is configured to display motion picture data and at least one of first and second graphic data on a screen. The first re-formatter on-screen unit converts motion picture data of a first aspect ratio, which is decoded by the video decoder, and first graphics data, which is produced by applying information relating to a caption corresponding to the motion picture data, into a second aspect ratio, when outputting the motion picture data of the first aspect ratio after conversion into the second aspect ratio, without converting the aspect ratio of second graphic data, which is produced by applying information relating to a program guide.