Patent ID: 8320735

Claim:
A playback device for performing a playback process, based on a file recorded on one of (i) a first recording medium having a first file system format and (ii) a second recording medium having a second file system format, each of the first recording medium and the second recording medium being a removable recording medium that is removable from the playback device, the playback device comprising: a manager configured to, when the first recording medium is mounted in the playback device, read an application from the first recording medium and activate the application; a gainer configured to gain an additional content corresponding to the first recording medium from an external device, in response to a request from the application; a writer configured to, in response to a request from the application, write a file including the additional content into a region of the second recording medium, the region being specified by a file path attached to the additional content; a searcher configured to, when the application requests to access the second recording medium with use of a file path in the first file system format, search for an accessible file on the second recording medium based on reference information; and a reader configured to, (i) if the accessible file is found by the search, read the accessible file from the second recording medium, and (ii) if the accessible file is not found by the search, read a file from the first recording medium, wherein the reference information has been recorded on the second recording medium, and indicates a file path in the second file system format that corresponds to the file path in the first file system format, management information on the first recording medium includes a plurality of identifiers for identifying the first recording medium, the file path in the second file system format indicated by the reference information includes parts of one of the identifiers, the parts being used to specify the accessible file and obtained by dividing the one of the identifiers into parts that each have a length complying with the second file system format, and the writer writes the file into the region specified with use of the file path including the parts of the one of the identifiers.