Audio Signal Coding Bit Allocation for Music Quality
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Solution Overview
Problem
Existing audio signal coding technologies face poor coding effects due to uniform bit allocation in frequency domain coding, leading to increased noise and reduced signal quality, especially when coding music at low code rates.
Innovation Solution
The method involves optimizing bit allocation for frequency domain signals by allocating more bits to low-frequency bands and adjusting bit distribution based on the highest frequency of the signal, ensuring better coding efficiency with the same number of bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform bit allocation is performed on the frequency domain signal, then the coding process is simple, but the coding effect is poor for some frequency domain signals
Solution Approach 1:
The patent applies local quality by differentiating bit allocation across different frequency bands. Instead of uniform allocation, the system allocates bits selectively to frequency bands based on their characteristics and importance, with different allocation strategies for low-frequency bands (which are more perceptually important) versus high-frequency bands, thereby improving coding effect while maintaining reasonable complexity
Solution Approach 2:
The patent changes the bit allocation parameter dynamically based on frequency band characteristics. The system adjusts the number of bits allocated to each frequency band according to parameters such as signal energy, perceptual importance, and decoding requirements, transforming the fixed uniform allocation into a flexible adaptive allocation scheme
2Productivity
If noise is filled into frequency domain signals not obtained by decoding, then the decoding process is completed, but extra noise is introduced which reduces output signal quality
Solution Approach 1:
The patent converts the harmful effect of noise filling into a beneficial process by using intelligent noise estimation and selective reconstruction. Instead of simply adding random noise, the system estimates the original signal characteristics from available decoded bands and reconstructs missing frequency components in a way that minimizes perceptual distortion, thereby completing decoding while preserving output quality
Solution Approach 2:
The patent introduces an intermediary noise estimation and signal reconstruction process between the decoded frequency bands and the final output. This intermediary step analyzes the characteristics of decoded bands, estimates missing components based on signal models and perceptual criteria, and synthesizes a quality-preserving reconstruction rather than direct noise filling
3Manufacturing precision
If more bits are allocated to low-frequency bands, then the coding effect for music is improved, but the total bit budget is consumed faster
Solution Approach 1:
The patent dynamically adjusts bit allocation parameters based on signal characteristics, code rate conditions, and frequency band importance. The system changes the bit allocation ratio between low-frequency and high-frequency bands adaptively, allocating more bits to low-frequency bands when music content is detected while maintaining overall bit budget constraints through hierarchical allocation strategies
Solution Approach 2:
The patent implements dynamic bit allocation that adapts to different operating conditions. The bit allocation scheme transitions from static uniform allocation to dynamic allocation that responds to signal type (speech vs. music), code rate, and frequency band characteristics, allowing optimal distribution of limited bit resources across different frequency bands based on current requirements
Data Source
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AI summary
Embodiments of the present invention provide methods and devices for signal coding and decoding. The signal coding method includes: obtaining a frequency domain signal according to an input signal; allocating predetermined bits to the frequency domain signal according to a predetermined allocation rule; adjusting the bit allocation for the frequency domain signal when a highest frequency of the frequency domain signal to which bits are allocated is greater than a predetermined value; and coding the frequency domain signal according to the bit allocation for the frequency domain signal.