Temporal Sublayer Timing Signaling for Accurate Video Decoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video coding standards lack efficient mechanisms for signaling source picture timing information, which is crucial for accurate decoding and display of video content, particularly in advanced coding systems like ITU-T H.266 and ECM.
Innovation Solution
The proposed techniques involve signaling a source picture timing information message with specific syntax elements that specify persistence and scale factors for determining picture intervals, allowing for conditional inclusion of additional information about temporal sublayers, ensuring accurate timing information is conveyed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If source picture timing information is signaled for each temporal sublayer individually, then decoding accuracy is improved, but bitstream complexity increases
Solution Approach 1:
The timing information is segmented by introducing a hierarchy with a common timing message applicable to all temporal sublayers and separate syntax elements for specific sublayers when needed. This allows baseline timing information to be shared while enabling precise overrides for individual sublayers, thus maintaining decoding accuracy without uniformly increasing complexity across all sublayers.
Solution Approach 2:
Instead of signaling complete timing information for each temporal sublayer separately (bottom-up approach), the patent inverts the approach by first signaling common timing information applicable to all sublayers (top-down), then adding sublayer-specific modifications only where necessary. This reduces overall bitstream complexity while preserving decoding accuracy.
2Measurement precision
If timing information is signaled with high granularity for each temporal sublayer, then playback accuracy is improved, but data transmission overhead increases
Solution Approach 1:
The patent merges timing information signaling by creating a common timing message structure that can be shared across multiple temporal sublayers. This consolidation reduces redundant data transmission while maintaining the ability to provide sublayer-specific timing information when necessary, thus reducing overall data transmission overhead while preserving playback accuracy.
Solution Approach 2:
Instead of providing complete timing information for every temporal sublayer unconditionally, the patent applies partial action by signaling common timing information that covers all sublayers, and only adding specific sublayer timing information when deviations are necessary. This avoids excessive data transmission while maintaining required playback accuracy.
3Loss of information
If separate timing messages are used for each temporal sublayer, then timing information completeness is improved, but processing complexity increases
Solution Approach 1:
The patent implements a nested structure where a common timing message (outer layer) contains baseline timing information applicable to all temporal sublayers, and sublayer-specific timing elements (inner layers) are nested within or referenced by the common message only when needed. This nested organization ensures timing information completeness while reducing processing complexity compared to completely separate messages for each sublayer.
Solution Approach 2:
The common timing message structure is designed to be universal, serving as a base for multiple temporal sublayers simultaneously. This multi-functional design allows a single timing message to provide complete timing information for all sublayers in many cases, eliminating the need for separate processing of individual sublayer messages and thus reducing overall processing complexity.
Data Source
AI summary
A device may be configured to decode video data based on information included in a source picture timing information message. In one example, a source picture timing information message includes a syntax element specifying a highest temporal sublayer that the source picture timing information message includes source picture timing information about, wherein when not present the value of the second syntax element is inferred to be equal to an indicated sublayer temporal identifier. In one example, a source picture timing information message includes respective instances of a syntax element specifying a scale factor used in determining a source picture interval of corresponding consecutive pictures in output order for each temporal sublayers to the specified highest temporal sublayer starting with 0 or the indicated sublayer temporal identifier.