A transmitting apparatus for transmitting a hierarchical structure of a directory
for hierarchically managing locations of contents data is disclosed, that comprises
a managing means for managing a hierarchical structure of a directory composed
of a container entry and a leaf entry, a container entry containing information
in the immediately lower hierarchical level thereof, a leaf entry being disposed
in the immediately lower hierarchical level of a container entry, a leaf entry
not containing information in the immediately lower hierarchical level thereof,
a detecting means for detecting a change of the hierarchical structure of the directory
managed by the managing means and obtaining first difference information and second
difference information, the first difference information being the difference of
container entries corresponding to the detected result, the second difference information
being the difference of leaf entries corresponding to the detected result, and
a transmitting means for transmitting third difference information for reproducing
the hierarchical structure of the directory at intervals of a predetermined time
period along with the first difference information and the second difference information.