HEVC Operation Point Descriptor Merging for Layer Dependency Signaling
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Solution Overview
Problem
Existing techniques for signaling dependency information between layers of layered HEVC bitstreams are inefficient and complex, with overlapping functionality between hierarchy and hierarchy extension descriptors, missing descriptions of descriptor presence, and inefficient signaling of profile, tier, and level (PTL) information.
Innovation Solution
A modified HEVC operation point descriptor is introduced, merging existing descriptors to reuse the name 'HEVC operation point descriptor', which includes a list of PTL structures associated with layers, operation points with output layer sets and partitioning schemes, and maps layers within operation points to PTL structures, while ensuring only necessary information is signaled and avoiding repetition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate hierarchy and hierarchy extension descriptors are used to signal dependency information between layers, then comprehensive dependency information can be provided, but the signaling process becomes complex and redundant
Solution Approach 1:
The patent merges the hierarchy descriptor and hierarchy extension descriptor into a unified descriptor structure. This combination eliminates the redundancy of having separate descriptors while maintaining the ability to signal comprehensive dependency information between layers. The unified descriptor integrates the functionality of both previous descriptors, reducing complexity in the signaling process.
Solution Approach 2:
The unified descriptor serves multiple functions simultaneously: it signals both the basic hierarchy information and the extended dependency relationships between layers. This multi-functional approach replaces the need for separate specialized descriptors, achieving both completeness and simplicity in the signaling mechanism.
2Measurement precision
If PTL information is signaled for each layer separately, then accurate profile, tier, and level information is provided, but the signaling becomes repetitive and inefficient
Solution Approach 1:
The patent combines PTL information signaling at the operation point level rather than repeating it for each individual layer. This merging approach maintains accurate PTL information while eliminating the redundancy of signaling the same profile, tier, and level data multiple times across different layers.
Solution Approach 2:
The PTL information is signaled once in advance at the operation point descriptor level, before the layer-specific information is processed. This preliminary signaling ensures that accurate PTL information is available without needing to repeat it for each layer, improving signaling efficiency while maintaining precision.
3Loss of information
If multiple descriptors are used to describe operation points and layers, then detailed information is available, but the overall signaling process becomes inefficient
Solution Approach 1:
The patent merges multiple separate descriptors into a consolidated operation point descriptor structure that contains both layer information and operation point information in a unified format. This integration maintains complete information about layers and their dependencies while reducing the total signaling time by eliminating the need to process multiple separate descriptors.
Data Source
AI summary
A device for processing a bitstream including video data, such as a demultiplexer, extracts a descriptor from the bitstream, wherein the bitstream includes layers of video data for operation points, separate from the descriptor, such that each operation point includes one or more of the layers of video data, and wherein the descriptor includes a set of profile, tier, and level (PTL) structures and data that associates each of the layers of each of the operation points with a corresponding one of the PTL structures, extracts video data for one of the operation points from the bitstream based at least in part on the PTL structures to which the layers of the one of the operation points correspond, and provides the extracted video data to a video decoder.