Audio Noise Coding by Spectral Region Under Bit Rate Limits
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Solution Overview
Problem
Existing audio signal encoding and decoding methods face challenges in improving sound quality using limited bit rates, particularly in effectively allocating bits to noise components in audio signals.
Innovation Solution
A method and apparatus that identify sections near important spectral components and sub-bands not to be output as noise components, allowing for efficient encoding and decoding by selectively encoding and decoding noise components based on energy ratios and noise levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If noise components are encoded with more bits, then sound quality is improved, but bit rate increases
Solution Approach 1:
The patent applies local quality by differentiating encoding precision across different frequency regions. Important spectral components are encoded with high precision while noise components are encoded with lower precision. Specifically, the encoder identifies spectral peaks and allocates more bits to their surrounding regions, while using fewer bits for noise components in other regions, thereby improving overall sound quality without uniformly increasing bit rate.
Solution Approach 2:
The patent changes encoding parameters dynamically based on the local characteristics of the audio signal. The bit allocation for noise components is adjusted according to the energy ratios between important spectral components and noise components. When noise energy is low relative to spectral components, fewer bits are allocated; when noise energy is higher, more bits are allocated, optimizing the trade-off between sound quality and bit rate.
2Measurement precision
If bits are allocated to noise components, then perceptible sound quality is improved, but encoding complexity increases
Solution Approach 1:
The patent segments the audio spectrum into different regions based on the importance of spectral components. It identifies spectral peaks and divides the frequency range into important regions (around spectral peaks) and noise regions (other areas). This segmentation allows the encoder to apply different encoding strategies to different regions, improving perceptible sound quality by focusing bits where they matter most while reducing encoding complexity through region-based processing.
Solution Approach 2:
The patent applies partial action by selectively encoding only the most important noise components rather than all noise components uniformly. It identifies regions where noise components contribute significantly to perceptible sound quality and allocates bits only to those regions, while using minimal or no bits for other noise regions. This approach improves perceptible sound quality with reduced encoding complexity by focusing resources on critical areas.
Data Source
AI summary
Provided is a method and apparatus for encoding/decoding an audio signal. Sections which are not used to output noise components near important spectral components and sub-bands which are not used to output noise components, are determined to be encoded or decoded, so that the efficiency of encoding and decoding an audio signal increases, and sound quality can be improved using less bits.