Arithmetic Coding Entry Points for Parallel Decoding Speed

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing arithmetic decoding processes, such as context-based adaptive binary arithmetic coding (CABAC), are highly sequential and cannot be parallelized, limiting decoding speed.

Innovation Solution

An encoding and decoding concept that allows for parallel decoding by providing entry point information in the bitstream, enabling multiple decoders to process different parts of the bitstream simultaneously, and includes an arithmetic encoder and decoder that renormalize internal parameters and use subintervals based on probability estimates to resume decoding from a predetermined point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If arithmetic decoding is performed using traditional sequential methods (CABAC), then decoding accuracy is maintained, but decoding speed is limited due to inability to parallelize

Engineering Contradiction:

Improvedecoding speedVSAvoidcoding procedure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The bitstream is divided into multiple segments with designated entry points, allowing multiple decoders to process different segments in parallel. Each segment is independently decodable by resetting the arithmetic decoder state at entry points, transforming the inherently sequential decoding process into a parallelizable structure without compromising decoding accuracy.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple decoders process different parts of the bitstream simultaneously, then decoding speed is improved, but entry point information and state management complexity increases

Engineering Contradiction:

Improvedecoding efficiencyVSAvoidentry point information management

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Entry point information is pre-calculated and embedded in the bitstream during the encoding phase. This preliminary action allows decoders to immediately jump to specific positions in the bitstream without requiring complex runtime calculations or state synchronization, simplifying the management of parallel decoding processes while maximizing decoding efficiency.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If the arithmetic encoder renormalizes internal parameters continuously during encoding, then coding precision is maintained, but encoding overhead and bitstream length increase

Engineering Contradiction:

Improvecoding precisionVSAvoidbitstream length

Core Design Contradiction:

Measurement precisionVSLoss of substance

Solution Approach 1:

Renormalization of internal parameters is performed selectively rather than continuously - specifically at entry points where parallel decoding will resume. This partial action maintains sufficient coding precision for accurate decoding while avoiding unnecessary renormalization operations that would inflate the bitstream length, achieving an optimal balance between precision and compression efficiency.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12580588B2Arithmetic encoder for arithmetically encoding and arithmetic decoder for arithmetically decoding a sequence of information values, methods for arithmetically encoding and decoding a sequence of information values and computer program for implementing these methods

Publication Date: 2026.03.17 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

AI summary

An encoding scheme is provided for arithmetically encoding a sequence of information values into an arithmetic coded bitstream by providing the bitstream with entry point information, allowing for resuming arithmetic decoding of the bitstream from a predetermined entry point onward. A respective decoding scheme is also provided. These encoding and decoding schemes provide more efficient encoding in view of the decoding speed.