Low-Frequency Sub-Band Envelope Tuning for Adaptive Bit Allocation
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Solution Overview
Problem
Existing frequency domain encoding algorithms face performance bottlenecks due to inadequate bit allocation in low frequency sub-bands, leading to poor signal encoding and decoding quality.
Innovation Solution
Selecting low frequency sub-bands, determining modification parameters based on energy and spectral characteristics, and performing bit allocation using modified envelope values to better meet bit requirements of each sub-band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bit allocation is performed directly according to frequency envelope size of each sub-band, then encoding process is simple, but low frequency sub-bands become bottlenecks leading to poor signal encoding and decoding quality
Solution Approach 1:
The patent segments the bit allocation process into multiple stages: first performing initial bit allocation based on frequency envelope, then identifying low frequency sub-bands that need improvement, and finally performing supplementary bit allocation specifically for those sub-bands. This segmentation allows targeted improvement of low frequency quality without completely redesigning the entire bit allocation system.
Solution Approach 2:
The patent applies local quality improvement by performing supplementary bit allocation specifically for low frequency sub-bands rather than uniformly across all sub-bands. The method identifies which sub-bands have insufficient quality and allocates additional bits only to those specific regions, optimizing resources while improving overall signal quality.
2Adaptability or versatility
If existing frequency domain encoding algorithms are used, then encoding speed is fast, but bit allocation cannot well adapt to bit requirements of each sub-band especially low frequency sub-bands
Solution Approach 1:
The patent performs preliminary identification of low frequency sub-bands and their bit requirements before performing supplementary bit allocation. By pre-calculating which sub-bands need improvement and how many additional bits they require, the method avoids complex real-time adjustments during encoding, thus maintaining encoding speed while improving adaptability.
Solution Approach 2:
The patent uses feedback from the initial encoding process to guide supplementary bit allocation. By analyzing the frequency envelope and identifying which low frequency sub-bands have insufficient quality, the system dynamically adjusts bit allocation based on actual performance needs, improving adaptability without significantly increasing complexity.
3Reliability
If more bits are allocated to low frequency sub-bands, then signal encoding quality improves, but total bit rate increases
Solution Approach 1:
The patent improves signal decoding quality by allocating additional bits specifically to low frequency sub-bands where quality is most critical, rather than uniformly increasing bits across all sub-bands. This localized approach improves perceived audio quality while minimizing the increase in total bit rate.
Solution Approach 2:
The patent applies partial action by performing supplementary bit allocation only for low frequency sub-bands that have insufficient quality, rather than reallocating bits across all sub-bands. This selective approach achieves quality improvement in critical regions while keeping the overall bit rate increase minimal.
Data Source
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AI summary
Embodiments of the present invention provide a signal processing method and device. The method includes: selecting M sub-bands from N sub-bands, where the N sub-bands are obtained by dividing a spectral coefficient of a current frame of a signal, and a frequency band of the M sub-bands is lower than a frequency band of K sub-bands in the N sub-bands except the M sub-bands; determining, according to performance information of the M sub-bands, to perform a modification operation on original envelope values of the M sub-bands, where the performance information is used to indicate an energy characteristic and a spectral characteristic that are of the M sub-bands; performing modification separately on the original envelope values of the M sub-bands, so as to acquire modified envelope values of the M sub-bands; and performing first bit allocation on the N sub-bands according to the modified envelope values of the M sub-bands and original envelope values of the K sub-bands. In the embodiments of the present invention, bit allocation better meets a bit requirement of each sub-band, and therefore, signal encoding and decoding performance can be improved.