Video Encoder Reference Picture List Update for Mixed NAL Unit Types
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video encoding and decoding technologies face challenges in efficiently handling mixed NAL unit types within a picture, leading to scenarios where necessary reference pictures for coding are not available, particularly in supporting 360-degree video streaming where subpictures with different types of VCL NAL units are required.
Innovation Solution
The proposed solution involves configuring video encoders and decoders to update reference picture lists such that no picture precedes an instant random access point in decoding order, ensuring that IDR pictures with subpictures include RPL syntax elements, allowing for the merging of subpictures from random-access and non-random-access pictures into a single coded picture conforming to VVC standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If subpictures from random-access and non-random-access pictures are merged into a single coded picture, then the versatility and adaptability of video processing is improved, but the complexity of reference picture list management increases
Solution Approach 1:
The patent segments the reference picture list into separate lists (first reference picture list and second reference picture list) to manage different types of reference pictures (random-access and non-random-access pictures) independently. This segmentation allows the system to handle mixed NAL unit types and merge subpictures from different picture types while maintaining manageable complexity through structured organization of reference picture data.
2Reliability
If reference picture lists are updated to exclude pictures preceding TRAP pictures in decoding order, then the reliability of reference picture availability is improved, but the complexity of reference picture list updates increases
Solution Approach 1:
The patent applies preliminary action by pre-defining the rule for reference picture list updates based on TRAP picture positions in decoding order. The system proactively identifies TRAP pictures and pre-configures the reference picture lists to exclude preceding pictures, ensuring reliable reference picture availability without requiring complex real-time calculations during the actual picture decoding process.
3Manufacturing precision
If IDR pictures with subpictures include RPL syntax elements, then the precision of reference picture list entries is improved, but the complexity of syntax element handling increases
Solution Approach 1:
The patent applies local quality by making RPL syntax elements optional and conditional rather than mandatory for all IDR pictures. The system selectively includes RPL syntax elements only when needed (when subpictures are present), allowing precise reference picture list entries for merged pictures while avoiding unnecessary complexity in standard IDR picture handling without subpictures.
Data Source
AI summary
A video encoder maintains a first reference picture list; maintains a second reference picture list; determines that a picture is an instantaneous decoding refresh (IDR) picture; determines that reference picture list syntax elements are present in a slice header for the IDR picture; and in response to determining that the picture is the IDR picture and that the reference picture list syntax elements are present in the slice header for the IDR picture, updates the first reference picture list and the second reference picture list such that no picture in the first reference picture list and no picture in the second reference picture list precedes, in output order or decoding order, any preceding instant random access point (IRAP) picture in decoding order.