IntraBC Prediction Mode Signaling in Video Coding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing Intra-block copy (IntraBC) mode in video coding, particularly for screen content coding in HEVC, faces inefficiencies due to its complex prediction process and dependency on Intra prediction partition modes, which increases computational complexity and bit length, especially when IntraBC prediction is less common than Inter prediction.
Innovation Solution
A method is introduced to simplify IntraBC prediction by modifying the binary tree structure for signaling prediction modes, allowing multiple partition modes for IntraBC coding, and incorporating flags to enable asymmetric and non-square partitioning, thereby reducing dependency on Intra prediction modes and improving coding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If IntraBC prediction mode is used with conventional binary tree structure for signaling prediction modes, then prediction accuracy may be maintained, but computational complexity and bit length increase significantly
Solution Approach 1:
The patent extracts IntraBC mode from the conventional Intra prediction binary tree structure and creates a separate, simplified signaling mechanism for it. This separation allows IntraBC to have its own dedicated flags and syntax elements independent of the complex Intra prediction mode hierarchy, thereby reducing computational complexity while maintaining prediction accuracy through dedicated IntraBC-specific signaling.
Solution Approach 2:
The patent segments the prediction mode signaling by introducing separate syntax elements for IntraBC (intra_bc_flag, intra_bc_mvs_flag) distinct from conventional Intra prediction modes. This segmentation allows the binary tree structure to be simplified for IntraBC specifically, reducing the overall computational complexity while preserving the ability to accurately signal IntraBC prediction modes when applicable.
2Adaptability or versatility
If IntraBC prediction mode is used with dependency on Intra prediction partition modes, then prediction flexibility is maintained, but bit length increases
Solution Approach 1:
The patent extracts the partition mode signaling for IntraBC from the conventional Intra prediction dependency structure. By introducing dedicated intra_bc_partition_mode_flag and separate syntax elements, it eliminates the need to signal full Intra prediction partition modes when IntraBC is used, thereby reducing bit length while maintaining prediction flexibility through IntraBC-specific partitioning flags.
Solution Approach 2:
Instead of signaling Intra prediction partition modes and then deriving IntraBC partitioning from them, the patent inverts the approach by introducing dedicated IntraBC partition mode flags that directly specify IntraBC partitioning without dependency on conventional Intra prediction modes. This inversion reduces bit length by eliminating redundant signaling while preserving flexibility.
3Adaptability or versatility
If conventional binary tree structure is used for signaling prediction modes, then comprehensive mode coverage is achieved, but processing time increases
Solution Approach 1:
The patent extracts IntraBC mode signaling from the conventional binary tree structure that covers all Intra and Inter modes. By creating a separate, streamlined signaling path for IntraBC with dedicated flags (intra_bc_flag, intra_bc_mvs_flag), it reduces processing time for IntraBC-specific operations while maintaining comprehensive mode coverage through the overall structure that still includes all other prediction modes.
Solution Approach 2:
The patent implements preliminary action by checking the intra_bc_flag early in the prediction mode signaling process. When this flag is set, the decoder can immediately proceed with IntraBC-specific processing without traversing the entire conventional binary tree structure, thereby reducing processing time while maintaining comprehensive mode coverage for cases where IntraBC is not used.
Data Source
Figure 1~2B
Figure 3A~4B
Figure 5A~5B
AI summary
A method of signaling of coding modes including an IntraBC mode (Intra-block copy mode) to improve the coding efficiency is disclosed. The embodiment takes into consideration the facts that Inter prediction is more common in Inter slices than IntraBC prediction. In another embodiment, a binary sub-tree is disclosed that includes all the partition modes associated with IntraBC mode and the binary sub-tree consists of only said all members of the partition mode group.