Panoramic Video Bit Rate Control for Temporal Distortion Propagation
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Solution Overview
Problem
Traditional panoramic video bit rate control methods fail to effectively address pixel redundancy and interframe distortion, leading to suboptimal coding performance due to high calculation complexity, which hinders real-time communication.
Innovation Solution
A zero-delay panoramic video bit rate control method that adjusts coding parameters based on the area stretching ratio during projection and temporal distortion propagation, utilizing CTU-level bit rate control and temporal global rate-distortion optimization to reduce coding complexity and improve performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional encoder does not use temporal correlation of distortion for coding, then calculation complexity is reduced, but coding performance has great room for improvement
Solution Approach 1:
The patent calculates the distortion temporal propagation influence factor based on the previous coding frame's reconstruction error and motion compensation prediction error before coding the current frame. This preliminary calculation of temporal correlation allows the encoder to account for interframe distortion relationships without requiring complex real-time analysis during the coding process, thus improving coding performance while maintaining acceptable calculation complexity.
2Manufacturing precision
If pixel redundancy is not addressed in projection process, then coding performance is affected, but adding correction mechanisms increases system complexity
Solution Approach 1:
The patent adjusts the coding parameter (Lagrange multiplier) based on the area stretching ratio calculated from the spherical surface area and projection area. By changing the coding parameter dynamically according to the geometric distortion characteristics of the projection, the system addresses pixel redundancy and improves coding performance without adding complex structural modifications to the encoding system.
3Quantity of substance
If bit rate control is applied to panoramic video, then bandwidth limitation and storage space requirements are met, but pixel redundancy and interframe distortion reduce coding efficiency
Solution Approach 1:
The patent implements a feedback mechanism where the distortion temporal propagation influence factor is calculated from the previous frame's coding results and used to adjust the current frame's coding parameters. This feedback loop allows the system to continuously optimize bit allocation based on actual distortion characteristics, improving coding efficiency while maintaining accurate bit rate control for bandwidth and storage constraints.
Data Source
AI summary
A zero-delay panoramic video bit rate control method that considers distortion temporal propagation aims to optimize target bit allocation and achieve global rate-distortion optimization in coding. It encompasses coding tree unit (CTU)-level bit rate control and temporal global rate-distortion optimization. CTU-level bit rate control involves optimizing target bit allocation and updating bit rate control parameters. Temporal global rate-distortion optimization utilizes the reconstruction error and motion compensation prediction error information of the previous coded frame to estimate the temporal dependence between CTUs in the current coding frame and those in the previous coded frame to adjust the coding parameters of the current CTU. The coding parameters are further fine-tuned according to the area stretching ratio encountered during the projection of the panoramic video from a 3D spherical surface to a 2D plane, taking into consideration the detrimental impact of interpolated redundant pixels on the coding process.