13. An apparatus for processing multimedia data, the apparatus comprising: a memory; and a processor configured to perform operations 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 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 segments represents a continuous temporal content portion in the audio-visual program; receiving segment group information defining first and second segment groups for the audio-visual program; generating a hierarchical data structure configured to facilitate browsing content in the audio-visual program, the hierarchical data structure including a first structural part which stores the received segment information and a distinct second structural part which stores the segment group information, wherein each of the first and second segment groups define a respective set of non-contiguous audio-visual segments which 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, wherein said segment group information 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 wherein the segment group information 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; and storing the hierarchical data structure including the segment information and the segment group information in the memory.
13. An apparatus for processing multimedia data, the apparatus comprising: a memory; and a processor configured to perform operations 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 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 segments represents a continuous temporal content portion in the audio-visual program; receiving segment group information defining first and second segment groups for the audio-visual program; generating a hierarchical data structure configured to facilitate browsing content in the audio-visual program, the hierarchical data structure including a first structural part which stores the received segment information and a distinct second structural part which stores the segment group information, wherein each of the first and second segment groups define a respective set of non-contiguous audio-visual segments which 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, wherein said segment group information 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 wherein the segment group information 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; and storing the hierarchical data structure including the segment information and the segment group information in the memory. 14. The apparatus of claim 13 , wherein said segment group information includes a level information.