Bitstream Conformance Testing with Operation-Point HighestTid Selection

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Solution Overview

Problem

Existing video coding standards, such as HEVC, do not specify how to set the highest temporal identifier (HighestTid) for performing bitstream conformance tests, leading to wasted computational resources and inefficiencies in parsing and handling HRD parameters.

Innovation Solution

A video encoder generates a bitstream with SPSs that include HRD parameters applicable to specific operation points, allowing devices to select and use these parameters for bitstream conformance tests, thereby optimizing HRD operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If existing video coding standards are used without specifying HighestTid for bitstream conformance tests, then the standards maintain broad compatibility, but computational resources are wasted and parsing efficiency deteriorates

Engineering Contradiction:
Improvebitstream conformance test efficiencyVSAvoidcomputational resource waste
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent changes the parameter HighestTid from an unspecified value to a specifically defined value equal to the greatest temporal identifier present in the bitstream. This parameter change enables efficient bitstream conformance testing by providing a clear criterion for selecting HRD parameters, thereby improving productivity while avoiding computational waste through precise parameter specification.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If HRD parameters are not selectively applied to operation points, then the decoding process remains simple, but parsing and handling efficiency deteriorates

Engineering Contradiction:
Improveparsing and handling efficiencyVSAvoidHRD parameter selection complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the bitstream into operation points, each characterized by a specific set of layer identifiers and a highest temporal identifier. By defining HighestTid for each operation point, the patent enables selective application of HRD parameters to specific operation points, improving parsing and handling efficiency while managing complexity through structured segmentation of the bitstream content.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different HRD parameters to different operation points based on their specific characteristics (layer identifiers and highest temporal identifier). This local quality approach ensures that each operation point is processed with the appropriate parameters, improving parsing efficiency without requiring universal parameter application, thus balancing complexity and efficiency.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the target highest temporal identifier is set to the greatest temporal identifier in the bitstream, then conformance testing accuracy improves, but processing time increases

Engineering Contradiction:
Improveconformance test accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary identification of the greatest temporal identifier present in the bitstream during the encoding or bitstream generation phase. By pre-determining this value and embedding it in the bitstream structure, the conformance test can directly use this pre-computed value without performing time-consuming searches during testing, thereby maintaining measurement precision while reducing processing time.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2898679B1Bitstream conformance test in video coding
Publication Date: 2025.12.03 QUALCOMM INC
  • EP2898679B1 patent drawingFigure 1
  • EP2898679B1 patent drawingFigure 2
  • EP2898679B1 patent drawingFigure 3

AI summary

A device performs a decoding process as part of a bitstream conformance test. As part of the decoding process, the device performs a bitstream extraction process to extract, from a bitstream, an operation point representation of an operation point defined by a target set of layer identifiers and a target highest temporal identifier. The target set of layer identifiers contains values of layer identifier syntax elements present in the operation point representation, the target set of layer identifiers being a subset of values of layer identifier syntax elements of the bitstream. The target highest temporal identifier is equal to a greatest temporal identifier present in the operation point representation, the target highest temporal identifier being less than or equal to a greatest temporal identifier present in the bitstream. The device decodes network abstraction layer (NAL) units of the operation point representation.