| US 7,580,610 B2 | ||
| Hierarchical storage scheme and data playback scheme for enabling random access to realtime stream data | ||
| Hiroshi Yao, Tokyo (Japan); and Hirokuni Yano, Tokyo (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Kawasaki-shi (Japan) | ||
| Filed on Feb. 18, 2004, as Appl. No. 10/779,631. | ||
| Application 10/779631 is a division of application No. 09/409424, filed on Sep. 30, 1999, granted, now 6,721,490. | ||
| Claims priority of application No. 10-278081 (JP), filed on Sep. 30, 1998; and application No. 10-368932 (JP), filed on Dec. 25, 1998. | ||
| Prior Publication US 2004/0170379 A1, Sep. 02, 2004 | ||
| Int. Cl. H04N 5/76 (2006.01) | ||
| U.S. Cl. 386—46 [711/118] | 21 Claims |
| 1. A hierarchical storage device comprising:
a library storage device configured to store realtime stream data in units of segments subdividing each realtime stream data;
a cache storage device configured to store selected segments among the segments stored in the library storage device;
a memory unit configured to store random access point segment information from which a possibility for each segment stored
in the library storage device to contain a point that can potentially be random accessed in future can be estimated; and
a control unit configured to control a selection of the selected segments to be stored in the cache storage device according
to the random access point segment information stored in the memory unit, the control unit including a discarding segment
selection unit configured to select segments that are candidates for discarding from the cache storage device, among the selected
segments stored in the cache storage device, according to the random access point segment information stored in the memory
unit,
wherein the control unit includes an update unit configured to update the random access point segment information for a segment
containing a certain point on the realtime stream data upon receiving a seek request with respect to said certain point.
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