A playback apparatus comprising: a reading unit operable to read, from a recording medium, a graphics stream including a plurality of Epochs, each Epoch including a plurality of Display Sets, wherein one of the Display Sets includes graphics data, control data and window definition information; a processor (12, 14) operable to decode the graphics data; an object buffer operable to store the decoded graphics data; a plane memory; and a controller; wherein the window definition information indicates a width, height and position of a rectangular area on the plane memory, the control data includes information indicating a type of the one of the Display Sets, the controller is operable, when the rectangular area is a part of the plane memory, to render the decoded graphics data stored in the object buffer within the rectangular area and not to render the decoded graphics data outside the rectangular area, the graphics stream includes PTS that indicates an execution start time for rendering the graphics data in the rectangular area, and PTS that indicates an execution end time for rendering the graphics data on the plane memory, the transfer rate between the object buffer and the plane memory is 256Mbps and the accuracy of said PTS is 90000Hz, the PTS that indicates the execution start time is represented by: PTS WDS = PTS PCS - 90000 x SIZE WDS. WIN / 256000000, where SIZE [WDS. WIN] is a total window size derived from the window definition information, the window definition information is fixed during one Epoch, and the Epoch is defined as a period from clearing the plane memory to clearing the plane memory again. a reading unit operable to read, from a recording medium, a graphics stream including a plurality of Epochs, each Epoch including a plurality of Display Sets, wherein one of the Display Sets includes graphics data, control data and window definition information; a processor (12, 14) operable to decode the graphics data; an object buffer operable to store the decoded graphics data; a plane memory; and a controller; wherein the window definition information indicates a width, height and position of a rectangular area on the plane memory, the control data includes information indicating a type of the one of the Display Sets, the controller is operable, when the rectangular area is a part of the plane memory, to render the decoded graphics data stored in the object buffer within the rectangular area and not to render the decoded graphics data outside the rectangular area, the graphics stream includes PTS that indicates an execution start time for rendering the graphics data in the rectangular area, and PTS that indicates an execution end time for rendering the graphics data on the plane memory, the transfer rate between the object buffer and the plane memory is 256Mbps and the accuracy of said PTS is 90000Hz, the PTS that indicates the execution start time is represented by: PTS WDS = PTS PCS - 90000 x SIZE WDS. WIN / 256000000, where SIZE [WDS. WIN] is a total window size derived from the window definition information, the window definition information is fixed during one Epoch, and the Epoch is defined as a period from clearing the plane memory to clearing the plane memory again.