A hierarchical memory scheme capable of improving a hit rate for the
segment containing the random access point rather than improving the
overall hit rate of the cache, and a data playback scheme capable of
automatically detecting positions that are potentially used as playback
start indexes by the user and attaching indexes, are disclosed. The
hierarchical storage device stores random access point segment information
from which a possibility for each segment to contain a point that can
potentially be random accessed in future can be estimated, and controls a
selection of the selected segments to be stored in the cache storage
device according to the random access point segment information. The data
playback device records a plurality of playback start indexes, each
playback start index being information regarding a playback position that
is determined according to the user input which is recorded when the user
input is in a prescribed pattern, and presents the plurality of playback
start indexes to a user so as to urge the user to select a desired
playback position.
