Video Decoder Reference Picture Tracking via Wrapped POC Cycle
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Solution Overview
Problem
Existing video coding technologies face challenges in efficiently managing and tracking reference pictures, particularly in reducing overhead signaling for long-term reference pictures, which can lead to ambiguity and increased bit requirements, affecting the accuracy and efficiency of video decoding.
Innovation Solution
The proposed method involves using a cycle parameter and modification parameters within the buffer description to track and decode reference pictures with reduced overhead, allowing for efficient identification and management of reference pictures in the decoded picture buffer, even when picture order count (POC) wraps around, and incorporating a scaling parameter for resolution adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If absolute long-term picture referencing is used, then reference picture identification is straightforward, but overhead signaling increases and bit requirements increase
Solution Approach 1:
The patent introduces a cycle parameter as an intermediary between the picture order count and the reference picture identification. Instead of directly using absolute POC values for long-term reference pictures, the cycle parameter wraps around after reaching a maximum value, serving as a mediator that reduces the number of bits required to signal reference picture identifiers while maintaining unique identification through the combination of cycle parameter and temporal identifier
Solution Approach 2:
The patent changes the parameter representation from absolute POC values to wrapped cycle parameters. By modifying how reference picture identifiers are encoded (using cycle parameters that wrap around instead of continuously increasing values), the system reduces overhead signaling while maintaining the ability to uniquely identify reference pictures through the combination of cycle parameter and temporal identifier
2Loss of information
If picture order count wraps around, then bit requirements are reduced, but ambiguity in reference picture tracking occurs
Solution Approach 1:
The patent adds an additional dimension to reference picture identification by introducing the temporal identifier alongside the wrapped cycle parameter. While the cycle parameter wraps around in one dimension (reducing bit requirements), the temporal identifier provides differentiation in another dimension, ensuring that reference pictures can be uniquely identified even when POC values repeat
Solution Approach 2:
The temporal identifier serves as an intermediary that resolves the ambiguity caused by POC wrapping. When cycle parameters wrap around and potentially collide, the temporal identifier acts as a mediator to distinguish between different reference pictures that may have the same cycle parameter value but different temporal positions
3Measurement precision
If more reference picture parameters are signaled, then decoding accuracy improves, but overhead and complexity increase
Solution Approach 1:
The patent segments the reference picture identification into multiple components: cycle parameter, temporal identifier, and list index. By dividing the identification process into these segments, the system can manage complexity more effectively, using compact representations for each segment while maintaining overall decoding accuracy through their combination
Data Source
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AI summary
A method for tracking a reference picture on a decoder is proposed. A modification of buffer description which includes "wrapped POC" and a poc cycle to signal long term pictures is introduced to reduce overhead of referencing pictures.