Abstract: In write-once media, there occurs wasted recording space at the time of update of an index file for AV file management. In view of this, a new index file is generated at the time of update, and thumbnail image data in an existing index file is referred to, whereby the wasted space is reduced, At the same time, attribute information is stored in the new index file, whereby high-speed access to minimum information required can be realized.

Abstract: The objective of the present invention is to manage reference movies using an index file, without causing the user to be perplexed. the reference movies are generated because of, for instance, the upper limit of the file size. The index file manages sets of information regarding the files being managed. Examples of these sets of information are information for determining whether or not a file is presented to the user, information for determining whether or not a file is original, and information indicating whether or not nondestructive editing has been done. Based on such information, the erasure, displaying a list, and so on are carried out. Thus, it is possible to manage the reference movies using the index file, without causing the user to be perplexed.

Abstract: A system records an AV stream composed of a plurality of record units (RUs) containing independently reproducible video units (VUs) of at least video or audio and program information (Movie atom) managing the AV stream, onto a recording medium. The program information contains a piece of information (Edit list atom) that manages a point of junction between the record units or between AV streams. In decoding the AV stream, decoding is halted or decoders are switched at the point of junction, based on the management information on the points of junction, for example.

Abstract: When the management area and the actual data area are separated beforehand in a filesystem and the management area is replicated to perform backup, the maximum number of files to be managed will be limited by the size of the management area because it is necessary to reserve the management area and the backup management area beforehand. In a filesystem in which the management area and the data area are recorded into a common area, it is impossible to use a replicating technique of the entire management area since there is no concept of the management area.

Abstract: When one recording medium is accessed from a multiple number of applications, the medium is usually divided into multiple areas. If this area division is performed and managed by the partitioning, it is difficult to change the partitions in size. Therefore, there has been the problem that the recording medium can not be used effectively. The recording medium is divided into multiple areas, and for each area, a dummy data is written into the blank space in the area so that dummy data can only be overwritten using a particular application or with a file of a particular type. This configuration makes it easy to divide the medium into multiple areas and change the areas in size.

Abstract: A speech recognition system automatically designates a scope of a partial reference pattern. Plural reference patterns, each of which ends in each of composing frames and starts from a preceding frame, are supposed and cumulative distances at every frame are calculated. A partial reference pattern that has a minimal distance value as compared with all other partial reference patterns is taken as a partial input speech recognizing result.