17. A method implemented by an apparatus for processing multimedia data, the method comprising: receiving segment information about an audio-visual program, the segment information including segment location information identifying a plurality of audio-visual segments in the audio-visual program, wherein the segment location information defines each audio-visual segment by a temporal position in a multimedia stream of the audio-visual program and wherein each audio-visual segment represents a continuous temporal content portion in the audio-visual program; receiving segment group information from a provider; and storing said received segment information and said segment group information in distinct first and second structural parts of a hierarchical data structure configured to facilitate browsing content in the audio-visual program in a client, wherein said segment group information: defines first and second segment groups for the audio-visual program, each of which defines a respective set of non-contiguous audio-visual segments that are selected from the plurality of audio-visual segments and identified in the segment group information by references to the corresponding segments in the segment information of the audio-visual program; specifies a respective group type and a respective duration for each of said first and second segment groups, the respective group types indicating that the first and second segment groups represent respective first and second content summaries related to objects or events as depicted in the audio-visual program; and includes segment order information defining that (i) the audio-visual segments within the first segment group are ordered relative to each other according to a time sequence that is significant for the first content summary's representation of the corresponding events or objects in the audio-visual program and (ii) the audio-visual segments within the second segment group are not ordered relative to each other according to any time sequence that is significant for the second content summary's representation of the corresponding events or objects in the audio-visual program.
17. A method implemented by an apparatus for processing multimedia data, the method comprising: receiving segment information about an audio-visual program, the segment information including segment location information identifying a plurality of audio-visual segments in the audio-visual program, wherein the segment location information defines each audio-visual segment by a temporal position in a multimedia stream of the audio-visual program and wherein each audio-visual segment represents a continuous temporal content portion in the audio-visual program; receiving segment group information from a provider; and storing said received segment information and said segment group information in distinct first and second structural parts of a hierarchical data structure configured to facilitate browsing content in the audio-visual program in a client, wherein said segment group information: defines first and second segment groups for the audio-visual program, each of which defines a respective set of non-contiguous audio-visual segments that are selected from the plurality of audio-visual segments and identified in the segment group information by references to the corresponding segments in the segment information of the audio-visual program; specifies a respective group type and a respective duration for each of said first and second segment groups, the respective group types indicating that the first and second segment groups represent respective first and second content summaries related to objects or events as depicted in the audio-visual program; and includes segment order information defining that (i) the audio-visual segments within the first segment group are ordered relative to each other according to a time sequence that is significant for the first content summary's representation of the corresponding events or objects in the audio-visual program and (ii) the audio-visual segments within the second segment group are not ordered relative to each other according to any time sequence that is significant for the second content summary's representation of the corresponding events or objects in the audio-visual program. 18. The method of claim 17 , wherein said segment group information includes a level information.