Video Reference Picture List Ordering for Coding Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
State-of-the-art video coding schemes always sort reference frames closest to the current picture to the top of lists, which may not always be the best frames for forward bi-predictive inter-picture prediction.
Innovation Solution
The method involves creating two reference lists for inter-picture prediction, where one list is ordered based on the quality of the reference pictures and the other on temporal distance, allowing for better selection of reference frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If reference frames closest to the current picture are sorted to the top of lists, then temporal proximity is optimized, but prediction quality may deteriorate when closest frames are not the best references
Solution Approach 1:
The patent makes the reference picture list ordering dynamic by introducing a flag that can switch between two ordering modes: temporal distance-based ordering and quality-based ordering. This allows the system to adapt the sorting criterion based on current prediction needs, resolving the contradiction between temporal proximity and prediction quality by selecting the appropriate ordering strategy for each case.
Solution Approach 2:
The patent changes the ordering parameter of reference pictures from solely temporal distance to a selectable parameter that can be either temporal distance or quality metric. By writing a flag into reference pictures and sorting based on this flag, the system enables parameter switching to optimize both temporal efficiency and prediction quality depending on the specific coding scenario.
2Productivity
If multiple reference lists are created for better prediction quality, then coding efficiency improves, but overhead information increases
Solution Approach 1:
The patent merges the advantages of multiple reference lists into a single unified list by using a flag-based sorting mechanism. Instead of maintaining separate reference lists for temporal and quality-based ordering, the system combines both criteria into one list that can be sorted according to the flag value, thereby reducing overhead information while preserving coding efficiency benefits.
Solution Approach 2:
The patent creates a universal reference picture list that can serve multiple functions depending on the flag setting. The same list structure and sorting mechanism handles both temporal distance-based reference selection and quality-based reference selection, eliminating the need for separate lists and reducing the overhead associated with maintaining multiple reference structures.
Data Source
AI summary
A method of encoding video using a plurality of reference pictures is provided. The method includes: writing one of a parameter or a flag into one or more reference pictures of the plurality of reference pictures, creating a first list of reference pictures comprising the plurality of reference pictures sorted based on the parameter or flag, and encoding a current picture of the video using at least the first list of reference pictures. A method of decoding video using a plurality of reference pictures is also provided. The method includes parsing one of a parameter or flag from one or more reference pictures of the plurality of reference pictures, creating a first list of reference pictures comprising the plurality of reference pictures sorted based on the parameter or flag, and decoding a current picture of the video using at least the first list of reference pictures. In addition, there are provided corresponding apparatuses for encoding and decoding video.