1. A reproducing apparatus for reproducing an audio-visual stream file using a first data group recorded on a first recording medium and a second data group recorded on a second recording medium different from the first recording medium, the reproducing apparatus comprising: an acquisition mechanism configured to acquire a manifest file, the manifest file containing recording medium path information indicating a path of a file contained in the second data group on the second recording medium, and virtual file system path information indicating a path of a file contained in the second data group in a virtual file system; a virtual file system generating mechanism configured to generate the virtual file system by mapping at least part of the second data group to the first data group in accordance with the virtual file system path information, said mapping including a conversion of file name, the first data group being managed in a directory structure containing an audio-visual stream directory managing the audio-visual stream file and a reproduction control file directory managing a reproduction control file as information for reproducing the audio-visual stream file; and a reproduction control mechanism configured to reproduce the audio-visual stream file managed in the audio-visual stream directory of the virtual file system, in accordance with the recording medium path information and the reproduction control file managed in the reproduction control file directory of the virtual file system.