Transform Skip Block Dimensions for Lossless Video Coding

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Solution Overview

Problem

Current video coding technologies face challenges in efficiently compressing digital video due to high bandwidth demands, particularly with the increasing number of connected devices, as they struggle to effectively utilize transform and quantization processes across various video blocks and components.

Innovation Solution

The proposed method involves determining the applicability of a transquant bypass mode for video blocks, which allows for representation without transform and quantization processes, and configuring bitstream representations to indicate this mode, enabling flexible coding modes based on block dimensions and components, thereby optimizing compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If transform and quantization processes are applied to all video blocks, then compression performance is improved, but coding complexity and processing overhead increase

Engineering Contradiction:

Improvecompression performanceVSAvoidcoding complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a transform skip mode that changes the processing parameters by selectively bypassing transform and quantization operations for certain video blocks based on prediction mode and block characteristics, thereby reducing coding complexity while maintaining compression efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent segments the video coding process by applying different processing paths to different color components (luma and chroma) and different block types, allowing transform skip mode to be independently controlled for each component based on its specific characteristics

Inventive Principle:

Principle #1Segmentation

2Productivity

If separate transform skip indications are signaled for each color component, then coding efficiency is improved, but bitstream overhead increases

Engineering Contradiction:

Improvecoding efficiencyVSAvoidbitstream overhead

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies different transform skip indications for different color components (luma and chroma) based on their local characteristics, allowing each component to be optimized independently while signaling only when differences exist, thus improving coding efficiency without excessive overhead

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent signals transform skip mode separately for luma and chroma components only when necessary (when they differ), rather than always signaling both, thereby achieving partial action that reduces bitstream overhead while maintaining coding efficiency

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If Luma Mapping with Chroma Scaling is disabled for transform skip blocks, then lossless coding is achieved, but compression ratio decreases

Engineering Contradiction:

Improvelossless codingVSAvoidcompression ratio

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent preemptively disables Luma Mapping with Chroma Scaling for blocks using transform skip mode to prevent potential quality degradation, ensuring lossless coding is maintained while the transform skip mode itself provides the necessary compression

Inventive Principle:

Principle #9Preliminary anti-action

4Speed

If transform skip mode is applied to large video blocks, then processing speed is improved, but coding precision may deteriorate

Engineering Contradiction:

Improveprocessing speedVSAvoidcoding precision

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

The patent dynamically adjusts the application of transform skip mode based on block size, prediction mode, and other characteristics, allowing larger blocks to use transform skip for speed while smaller or more complex blocks maintain traditional transform for precision

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11490086B2Block dimension settings of transform skip mode

Publication Date: 2022.11.01 BYTEDANCE INC

AI summary

Devices, systems and methods for lossless coding for visual media coding are described. An exemplary method for video processing includes determining, based on a current video block of a video satisfying a dimension constraint, that coding modes are enabled for representing the current video block in a bitstream representation, where the dimension constraint states that a same set of allowed dimensions for the current video block is disabled for the coding modes, and where, for an encoding operation, the coding modes represent the current video block in the bitstream representation without using a transform operation, or where, for a decoding operation, the coding modes are used to obtain the current video block without using an inverse transform operation; and performing a conversion between the current video block and the bitstream representation of the video based on one of the coding modes.