Recording medium, recording method, reproduction apparatus and method, and computer-readable program

A reproduction apparatus for reproducing a digital stream generated by multiplexing a video stream and a graphics stream, comprising:

• a video decoder operable to decode the video stream to generate a moving picture;
• and
• a graphics decoder operable to decode the graphics stream to generate graphics, and overlay the graphics and the moving picture, wherein:
• the graphics stream includes a plurality of display sets each of which is used for a graphics display, the display set including a control segment and graphics data;
• and
• the graphics decoder performs pipeline processing, by starting processing the display set at or after a time at which, during an active period of a control segment in an immediately preceding display set, transfer of graphics generated by decoding graphics data in the immediately preceding display set to a buffer is completed.

A method of recording onto a recording medium, comprising the steps of:

• generating application data;
• and
• recording the application data to the recording medium, wherein:
• the application data includes a digital stream generated by multiplexing a video stream and a graphics stream;
• the graphics stream includes a plurality of display sets each of which is used for a graphics display;
• the display set includes a control segment and graphics data, the control segment including time information that designates an active period of the control segment in the display set on a reproduction time axis of the video stream;
• and
• when the active period of the control segment in the display set overlaps with an active period of a control segment in an immediately preceding display set, the time information designates the active period of the control segment in the display set to start at or after a time at which, during the active period of the control segment in the immediately preceding display set, transfer of graphics generated by decoding graphics data in the immediately preceding display set is completed.

A computer-readable program used for enabling a computer to reproduce a digital stream generated by multiplexing a video stream and a graphics stream, the program enabling the computer to perform the steps of:

• decoding the video stream to generate a moving picture;
• and
• decoding the graphics stream to generate graphics, and overlaying the graphics and the moving picture, wherein:
• the graphics stream includes a plurality of display sets each of which is used for a graphics display, the display set including a control segment and graphics data;
• and
• the step of decoding the graphics stream perform pipeline processing, by starting processing the display set at or after a time at which, during an active period of a control segment in an immediately preceding display set, transfer of graphics generated by decoding graphics data in the immediately preceding display set to a buffer is completed.

A method of reproducing a digital stream generated by multiplexing a video stream and a graphics stream, comprising the steps of:

• decoding the video stream to generate a moving picture;
• and
• decoding the graphics stream to generate graphics, and overlaying the graphics and the moving picture, wherein:
• the graphics stream includes a plurality of display sets each of which is used for a graphics display, the display set including a control segment and graphics data;
• and
• the step of decoding the graphics stream performs pipeline processing, by starting processing the display set at or after a time at which, during an active period of a control segment in an immediately preceding display set, transfer of graphics generated by decoding graphics data in the immediately preceding display set to a buffer is completed.