ISOBMFF Track Grouping Reduces Data Redundancy
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Solution Overview
Problem
Existing solutions for describing and signaling groups of components in ISO Base Media File Format (ISOBMFF) face issues such as overhead and complexity in signaling properties, lack of dynamicity in properties and component lists over time, and data redundancy.
Innovation Solution
The proposed solution involves declaring the list of existing groups of tracks in a single location within the presentation file and mutualizing common properties shared by tracks within a group, allowing for dynamic changes in group properties and track compositions over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If groups of tracks are described using existing ISOBMFF mechanisms, then track grouping functionality is provided, but data redundancy and signaling overhead increase
Solution Approach 1:
The patent merges the description of multiple tracks into a single group entry in the Groups List box, where common properties are defined once at the group level rather than being repeated in each track. This combining approach eliminates data redundancy while maintaining the ability to describe grouped tracks.
Solution Approach 2:
The group entry in the Groups List box serves as a universal template that can be referenced by multiple tracks. The group entry defines common properties that apply universally to all member tracks, reducing the need for repetitive signaling and lowering overall data overhead.
2Reliability
If properties are signaled for each track individually, then complete track information is provided, but signaling complexity and overhead increase
Solution Approach 1:
The patent segments track properties into two categories: common properties that are shared by multiple tracks and are defined once at the group level, and specific properties that are unique to individual tracks. This segmentation reduces signaling complexity by eliminating redundant transmission of common properties while maintaining complete track information.
Solution Approach 2:
The patent implements a nested structure where tracks are nested within groups, and group entries are nested within the Groups List box. This hierarchical nesting allows common properties to be defined at the group level and automatically inherited by member tracks, reducing overall signaling complexity while preserving complete track information.
3Device complexity
If static group definitions are used in ISOBMFF, then simple structure is maintained, but dynamicity in group properties and track compositions is lost
Solution Approach 1:
The patent introduces dynamicity by allowing the Groups List box to be updated with new group entries that can modify or supersede previous group definitions. The version field in group entries enables the structure to evolve over time, allowing dynamic changes in group properties and track compositions while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent implements a feedback mechanism where the version field in group entries provides information about the state of group definitions. This allows parsers to understand whether they are dealing with the original static definition or an updated dynamic definition, enabling the system to adapt to changing requirements while maintaining structural simplicity.
Data Source
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AI summary
There are provided a device and a method for generating timed media data, the timed media data comprising samples, the method comprising: obtaining samples of the time media data ; creating tracks each comprising at least one of the obtained samples; and generating a presentation file comprising descriptive metadata associated with the created tracks, wherein the descriptive metadata comprise at least one track group box describing at least one group of created tracks, all the tracks belonging to a same group sharing properties, wherein a list of existing groups of tracks is declared in one single location in the presentation file, and wherein the properties shared by the tracks of a group of the list are declared at the same single location in the presentation file.