Hierarchical and reduced index structures for multimedia files
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 decoding a media file for playing back by a playback device, comprising:
a media file comprising a plurality of groups of frames, wherein each group of frames comprises a set of encoded video frames; and
a hierarchical index comprising a top-level index indexing references to the plurality of group of frames, wherein each reference to a frame in the plurality of frames comprises a seek point referencing a location from which an individual frame of encoded video can be retrieved;
requesting the hierarchical index;
receiving a user request;
selecting a seek point from the hierarchical index based on the user request;
requesting at least one encoded video frame using the selected seek point from the selected subset of seek points by calculating an offset between the selected seek point and the nearest group of frames;
selecting a group of frames from the plurality of groups of frames using the hierarchical index and the calculated offset; and
decoding at least one encoded video frame in the selected group of frames.
2. The method of claim 1 , wherein the media file being a separate file from a file containing the hierarchical index.
3. The method of claim 1 , wherein the media file contains the hierarchical index.
4. The method of claim 3 , wherein the hierarchical index is stored as a set of distributed clusters within the multimedia file.
5. The method of claim 1 , further comprising displaying a video frame on a display screen, the displayed video frame being a frame that corresponds to the decoded at least one encoded video frame.
6. The method of claim 1 , wherein the user request further comprises a fast forward function for determining the subset of seek points, wherein the subset of seek points comprises a predetermined plurality of seek points.
7. The method of claim 1 , wherein the hierarchical index further comprises metadata describing the data type for each frame of video within a group of frames.
8. The method of claim 1 , wherein the set of frames in a group of frames is decoded in a decoding order.