External Decoder Refresh Picture Order Count Restriction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video coding technologies face challenges in efficiently compressing and decompressing video data, particularly in limited bandwidth scenarios, where the difference in picture order count values for consecutive pictures in a list affects coding efficiency and resource utilization.
Innovation Solution
The method restricts the difference in picture order count values for consecutive pictures to a limited range when using an external decoder refresh (EDR) picture, reducing the number of bits needed for signaling and improving coding efficiency by using external reference pictures for inter prediction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the difference between picture order count values for consecutive pictures is not restricted, then the coding flexibility is maintained, but the number of bits needed for signaling increases and coding efficiency deteriorates
Solution Approach 1:
The patent applies parameter changes by restricting the picture order count (POC) difference between consecutive pictures in the list to a specific range (greater than -MaxPicOrderCntLsb/2 and less than MaxPicOrderCntLsb/2). This parameter restriction reduces the number of bits needed for signaling POC values while maintaining coding flexibility, directly improving coding efficiency and reducing bitstream complexity
Solution Approach 2:
The patent implements partial action by applying the POC difference restriction only to specific picture lists (first and second reference picture lists) used for external decoder refresh, rather than all picture lists. This selective application reduces signaling overhead for critical pictures while maintaining flexibility for other pictures, balancing coding efficiency with adaptability
2Measurement precision
If more bits are used for signaling picture order count values, then the precision of picture identification is improved, but the processor, memory, and network resource usage increases
Solution Approach 1:
By changing the parameter constraint for POC values (restricting differences to within ±MaxPicOrderCntLsb/2), the patent reduces the number of bits required to signal POC values. This parameter restriction maintains sufficient precision for picture identification while significantly reducing processor, memory, and network resource consumption during encoding and decoding operations
3Adaptability or versatility
If the picture order count difference range is expanded, then the adaptability to different video sequences is improved, but the coding efficiency and resource utilization deteriorates
Solution Approach 1:
The patent optimizes the POC difference range parameter to balance adaptability and efficiency. By setting the restriction range to greater than -MaxPicOrderCntLsb/2 and less than MaxPicOrderCntLsb/2, it maintains sufficient adaptability for various video sequences while improving coding efficiency and resource utilization, avoiding the overhead of larger ranges
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of decoding a coded video bitstream is provided. The method includes receiving a bitstream containing an external decoder refresh (EDR) picture and a list of pictures for the EDR picture, wherein the list of pictures lists pictures referred to by entries in a first reference picture list, the pictures referred to by the entries in a second reference picture list, and external pictures in increasing decoding order, and wherein a difference between picture order count values for any two consecutive pictures in the list of pictures is greater than one half of a negative of maximum picture order count least significant bits and less than one half of the maximum picture order count least significant bits; obtaining one of the external pictures referred to in the list of pictures; and decoding the EDR picture using the external reference picture that was obtained.