Hierarchical and reduced index structures for multimedia files

Abstract

Playback and distribution systems and methods for multimedia files are provided. The multimedia files are encoded with indexes associated with the content data of the multimedia files. Through the use of the indexes, playback of the content is enhanced without significantly increasing the file size of the multimedia file.

1 . A method of playing back content by a playback device stored in a media file, the method comprising:
 providing a media file to a playback device, the media file having content data, cue data and a hierarchical index, the content data having a plurality of media frames, the cue data being associated with each frame of the plurality of frames and the hierarchical index being associated with a subset of the cue data;   decoding the content data by a playback device;   displaying content on a display screen from the decoded content data;   receiving a user request;   locating the index based on the user request; and   decoding one or more media frames from the subset of the cue data based on the located index.   
     
     
         2 . The method of  claim 1  wherein the index has reference values that point directly to particular media frames of the plurality of media frames. 
     
     
         3 . The method of  claim 1  wherein the hierarchical index includes pointers to the cue data within the media file and further comprising accessing the cue data through the pointers to locate a frame to be decoded. 
     
     
         4 . The method of  claim 1  wherein the hierarchical index is associated with a subset of the plurality of media frames through a second hierarchical index and further comprising locating a subset of the second hierarchical index based on the hierarchical index relative to the user request. 
     
     
         5 . The method of  claim 4  wherein decoding one or more media frames from the subset of the plurality of media frames is based on the located subset of the second hierarchical index. 
     
     
         6 . The method of  claim 1  wherein the media file has an upper hierarchical index associated with the hierarchical index and the hierarchical index associated with one or more media frames from the subset of the plurality of media frames and wherein the upper hierarchical index has a greater number of associations with one or more media frames than the hierarchical index. 
     
     
         7 . A method of encoding a media file for playing back by a playback device, comprising:
 incorporating seek locations with content data, the content data having audio, video and subtitle tracks, the seek locations identifying particular timestamps for particular frames within the audio, video or subtitle tracks;   incorporating an index referencing the incorporated seek locations; and   creating a media file having the content data, the incorporated seek locations, and the incorporated index.   
     
     
         8 . The method of  claim 7  wherein incorporating the index further comprises interleaving an index between audio and video tracks. 
     
     
         9 . The method of  claim 8  wherein the index points only to key frames within the audio, video or subtitle tracks. 
     
     
         10 . The method of  claim 9  wherein the index contains locations and timestamps to key frames. 
     
     
         11 . A system for playback of a media file, comprising:
 a media server configured to transmit a media file having at least one index having pointers that reference at least one frame of media content within the media file; and   a client processor in network communication with the media server and configured to send requests for the media file to the media server, the media server configured to transmit the media file requested, the client processor comprises a playback engine configured to locate a pointer from the at least one index to locate and decode the portions of the media file based on the located pointer to comply with user playback instructions.   
     
     
         12 . The system of  claim 11  wherein the at least one index contains pointers to key frames only. 
     
     
         13 . The system of  claim 11  wherein the at least one index contains pointers to another index that contains pointers that reference at least one frame of media content within the media file. 
     
     
         14 . The system of  claim 11  wherein the at least one index comprises a plurality of pointers, each pointer referencing a frame of media content and the plurality of pointers in its entirety referencing each frame of media content. 
     
     
         15 . The system of  claim 11  wherein the at least one index comprises a coarse index having pointers referencing frames of media content and a fine index having pointers referencing frame of the media content, the fine index having more pointers than the coarse index. 
     
     
         16 . The system of  claim 11  wherein the at least one index comprises a reduced index having pointers only to access frames of the media content.