3D Down-Mix Decoding with Spatial Extraction for Multi-Channel Audio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio signal processing technologies fail to efficiently reproduce multi-channel signals with 3D effects in various reproduction environments, particularly when using fewer channels, such as 2-channel speakers like headphones, which limits the immersive audio experience.
Innovation Solution
The method involves extracting 3D down-mix signals and spatial information from an input bitstream, performing 3D rendering operations to remove 3D effects, and generating multi-channel signals using this information, enabling efficient encoding and decoding of audio signals to adapt to different reproduction environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multi-channel signals are reproduced using 2-channel speakers, then the reproduction device complexity is reduced, but the 3D sound effect quality deteriorates
Solution Approach 1:
The patent applies parameter changes by transforming the multi-channel signal parameters into a down-mixed format with spatial information. The encoding apparatus converts the original multi-channel signal into a down-mixed signal with fewer channels while preserving spatial parameters (inter-channel level difference, inter-channel time difference, inter-channel phase difference) that can be used to reconstruct 3D spatial effects during decoding, thus maintaining sound quality while reducing reproduction device complexity
Solution Approach 2:
The patent extracts spatial information from the multi-channel signal during encoding. The encoding apparatus separates the spatial characteristics (direction, position, distance of sound sources) from the audio content and encodes them as independent parameters. This extracted spatial information is then transmitted along with the down-mixed signal, allowing the decoding apparatus to reconstruct 3D spatial effects without requiring the original multi-channel configuration, thus resolving the contradiction between device complexity and sound quality
2Adaptability or versatility
If 3D rendering operations are performed on down-mix signals, then the adaptability to different reproduction environments is improved, but the processing time increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and encoding spatial information during the encoding phase. The encoding apparatus performs the complex spatial analysis and parameter extraction in advance, storing these parameters in the bitstream. During decoding, the apparatus only needs to retrieve and apply these pre-computed parameters, significantly reducing real-time processing requirements while maintaining adaptability to different reproduction environments
3Manufacturing precision
If spatial information is extracted and transmitted in the bitstream, then the sound quality is improved, but the data transmission volume increases
Solution Approach 1:
The patent efficiently manages data transmission by selectively encoding and transmitting only the essential spatial parameters (inter-channel level difference, inter-channel time difference, inter-channel phase difference) at optimized precision levels. The encoding apparatus transforms the spatial information into compact parameter representations that convey the necessary 3D spatial characteristics while minimizing the bitstream overhead, thus balancing sound quality improvement with data transmission efficiency
Data Source
AI summary
An encoding method and apparatus and a decoding method and apparatus are provided. The decoding method includes extracting a three-dimensional (3D) down-mix signal and spatial information from an input bitstream, removing 3D effects from the 3D down-mix signal by performing a 3D rendering operation on the 3D down-mix signal, and generating a multi-channel signal using the spatial information and a down-mix signal obtained by the removal. Accordingly, it is possible to efficiently encode multi-channel signals with 3D effects and to adaptively restore and reproduce audio signals with optimum sound quality according to the characteristics of a reproduction environment.