Sample Adaptive Offset Compensation in Video Coding

Solution Overview

Problem

Conventional sample adaptive offset (SAO) schemes in video coding require multiple passes through the picture buffer for mode decision, leading to high power consumption and latency, and are computationally intensive due to rate-distortion optimization processes.

Innovation Solution

A method and apparatus for SAO compensation that determines pixel categories based on relations with neighboring pixels, using a look-up table and sign function for efficient classification, and applies offset values without needing to complete processing of all neighboring pixels, thereby reducing memory access and computational load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional SAO schemes perform mode decision by accessing the picture buffer multiple times for rate-distortion optimization, then encoding accuracy is improved, but power consumption increases and latency increases

Engineering Contradiction:

Improveencoding accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent pre-computes and stores offset values for different pixel categories before the actual encoding process. During mode decision, instead of accessing the picture buffer multiple times to compute offsets, the system retrieves pre-computed offset values from storage, significantly reducing power consumption and latency while maintaining encoding accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a copy of the picture buffer in a local buffer within the encoder/decoder device. This local copy allows multiple accesses without requiring external memory transactions, reducing power consumption and latency during the rate-distortion optimization process while maintaining encoding accuracy

Inventive Principle:

Principle #26Copying

2Measurement precision

If conventional SAO schemes perform mode decision by accessing the picture buffer multiple times, then encoding accuracy is improved, but processing time increases

Engineering Contradiction:

Improveencoding accuracyVSAvoidlatency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-computes and stores offset values for different pixel categories before the actual encoding process. During mode decision, instead of accessing the picture buffer multiple times to compute offsets, the system retrieves pre-computed offset values from storage, significantly reducing power consumption and latency while maintaining encoding accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a copy of the picture buffer in a local buffer within the encoder/decoder device. This local copy allows multiple accesses without requiring external memory transactions, reducing power consumption and latency during the rate-distortion optimization process while maintaining encoding accuracy

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If conventional SAO schemes use multiple passes through the picture buffer for offset computation, then compensation accuracy is improved, but computational load increases

Engineering Contradiction:

Improvecompensation accuracyVSAvoidcomputational efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent pre-computes and stores offset values for different pixel categories before the actual encoding process. During mode decision, instead of accessing the picture buffer multiple times to compute offsets, the system retrieves pre-computed offset values from storage, significantly reducing power consumption and latency while maintaining encoding accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a copy of the picture buffer in a local buffer within the encoder/decoder device. This local copy allows multiple accesses without requiring external memory transactions, reducing power consumption and latency during the rate-distortion optimization process while maintaining encoding accuracy

Inventive Principle:

Principle #26Copying

Data Source

PatentUS9432670B2Apparatus and method of efficient sample adaptive offset

Publication Date: 2016.08.30 HFI INNOVATION INC

AI summary

A method and apparatus for sample adaptive offset (SAO) compensation of reconstructed video data are disclosed. In one embodiment, the relation between the current pixel and said one or more neighboring pixels is stored so that the SAO compensated current pixel can replace the current pixel without buffering the to-be-processed pixels for classification. The SAO process may be performed on a region by region basis to adapt to the local characteristics of the picture.