A recording medium, method, and apparatus for reproducing text subtitle
streams are disclosed. A microcomputer initially reads a set of PlayItems
and a SubPlayItem included in a PlayList which is recorded on a recording
medium, and it further reads synchronization information included in the
SubPlayItem. Each PlayItem is configured to reproduce at least one main
AV stream, and the SubPlayItem is configured to reproduce a text subtitle
stream. The synchronization information indicates a presentation start
time of the SubPlayItem on a global time axis of the PlayList. When the
PlayList is randomly accessed at a random access time on the global time
axis, the microcomputer calculates a corresponding access time on a time
axis of the SubPlayItem. Then a text subtitle decoder decodes for
presentation a dialog presentation segment with the closest dialog start
time after the corresponding access time on the axis of the SubPlayItem.