Wrap-Around Motion Compensation Signaling in Video Coding
Solution Overview
Problem
Existing video coding standards face challenges in efficiently signaling information related to wrap-around motion compensation, slice layout, and slice address, particularly in advanced standards like VVC/H.266, which aim to improve compression efficiency.
Innovation Solution
The proposed method involves signaling a wrap-around motion compensation flag to determine if wrap-around motion compensation is enabled, and then receiving data indicating the difference between the picture width and an offset used for determining a horizontal wrap-around position. Additionally, the method includes signaling variables in the picture parameter set to indicate the number of slices and subpictures, and determining whether a picture header syntax structure is present within a slice header to correctly signal slice addresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wrap-around motion compensation is enabled with detailed offset signaling, then motion compensation precision is improved, but bitstream overhead increases
Solution Approach 1:
The patent changes the parameter representation by signaling the difference between picture width and offset (rather than the offset itself) only when wrap-around motion compensation is enabled. This conditional parameter signaling reduces bitstream overhead while maintaining precision when needed.
Solution Approach 2:
The patent introduces a dynamic flag (wrap-around motion compensation flag) that controls whether detailed offset signaling is performed. This allows the system to adapt between different signaling modes based on whether wrap-around motion compensation is actually used, optimizing the trade-off between precision and overhead.
2Manufacturing precision
If comprehensive slice and subpicture signaling is implemented, then slice layout accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the picture into slices and subpictures with distinct signaling structures. By dividing the picture into manageable segments with dedicated parameter sets, the system achieves accurate slice layout while organizing complexity into modular, manageable units.
Solution Approach 2:
The patent performs preliminary signaling of slice and subpicture parameters in the picture parameter set before actual decoding. This advance signaling allows the decoder to be prepared with all necessary layout information, reducing runtime complexity while maintaining accuracy.
3Reliability
If picture header syntax structure is always present in slice header, then slice address signaling reliability is improved, but bitstream overhead increases
Solution Approach 1:
The patent makes the picture header syntax structure in the slice header dynamic and conditional. It is only present when actually needed for slice address signaling, controlled by appropriate flags. This reduces bitstream overhead by eliminating redundant structures while maintaining reliability when required.
Data Source
AI summary
The present disclosure provides systems and methods for wrap-around motion compensation. One exemplary method comprises: receiving a wrap-around motion compensation flag; determining whether a wrap-around motion compensation is enabled based on the wrap-around motion compensation flag; in response to a determination that the wrap-around motion compensation is enabled, receiving data indicating a difference between a width of the picture and an offset used for determining a horizontal wrap-around position; and performing a motion compensation according to the wrap-around motion compensation flag and the difference.