A playback apparatus for playing a digital stream in conjunction with an application includes a package management unit operable to generate package information by merging files recorded on a first recording medium and a second recording medium, in accordance with merge management information, and a selection unit operable to detect a plurality of playable titles from the package information, and select one of the detected titles as a current title. After the application requests the package management unit to update the merge management information, by specifying new merge management information, the package management unit changes a file referenced from the newly specified merge management information to read-only before updating the package information, and at a point at which digital stream playback stops due to a current title change by the selection unit, the package management unit generates new package information by combining files recorded on the first and second recording media, in accordance with the newly specified merge management information.