HEVC CABAC Lossless Coding With High-Throughput Binarization

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Solution Overview

Problem

High bit-rate encoding and decoding in HEVC using CABAC are computationally complex and resource-intensive due to the large number of models required, particularly in lossless coding modes, leading to significant processing time and resource consumption.

Innovation Solution

The implementation of a High Throughput Binarization Mode (HTB) that uses a bypass coding mode and simplified signing structures, omitting computationally expensive context estimation and probability update stages, and employing adaptive binarization with VLC tables to reduce processing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If CABAC with context adaptive coding is used for lossless compression, then compression performance is improved, but computational complexity and processing time increase significantly

Engineering Contradiction:
Improvecompression performanceVSAvoidcomputational complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent segments the context models into multiple categories (e.g., luma intra prediction, luma inter prediction, chroma prediction) and further divides each category into sub-categories based on prediction modes and block sizes. This segmentation allows the decoder to selectively apply only the necessary context models for each specific coding scenario, reducing the overall computational burden while maintaining compression effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a simplified CABAC mode where only a subset of context models is used instead of the full set. By applying partial action (using fewer context models than the standard), the patent reduces computational complexity while still achieving acceptable compression performance, particularly for high-bitrate scenarios where full CABAC may be overly complex.

Inventive Principle:
Principle #16Partial or excessive action

2Loss of information

If full CABAC context models are used for high bit-rate encoding, then compression effectiveness is maintained, but processing resources and time consumption increase

Engineering Contradiction:
Improvecompression effectivenessVSAvoidprocessing efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent introduces dynamic selection of context model subsets based on coding conditions. The decoder dynamically determines which context models to apply based on factors such as prediction mode, block size, and bit-rate characteristics. This dynamic approach allows the system to adapt to different scenarios, using more sophisticated models when necessary and simpler models when sufficient, thereby optimizing processing efficiency while maintaining compression effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of context model selection by introducing a simplified mode that uses a reduced set of context models. By altering this parameter (the number and type of context models used), the patent achieves a balance between compression effectiveness and processing efficiency, particularly benefiting high-bitrate applications where the full set of context models provides diminishing returns.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If context estimation and probability update stages are performed, then coding accuracy is improved, but processing time and resource consumption increase

Engineering Contradiction:
Improvecoding accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts and removes the computationally expensive context estimation and probability update stages from the standard CABAC process in the simplified mode. By taking out these stages, the patent significantly reduces processing time and resource consumption while still maintaining acceptable coding accuracy through the use of predetermined or pre-computed probability values.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS8581753B2Lossless coding technique for CABAC in HEVC
Publication Date: 2013.11.12 HUAWEI TECH CO LTD
  • US8581753B2 patent drawing
  • US8581753B2 patent drawing
  • US8581753B2 patent drawing

AI summary

A system utilizing a lossless coding technique for CABAC in HEVC is described. The system includes a first and second electronic device. The first electronic device encodes according to a lossless coding technique for CABAC in HEVC. The second electronic device decodes according to a lossless coding technique for CABAC in HEVC.