Audio Signal Decoding with SBR Smoothing for High-Range Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio decoding methods using SBR (Spectral Band Replication) result in auditory degradation due to energy depressions in the low-range signal, leading to inaccuracies in generating high-range components, which affects the quality of the audio output.
Innovation Solution
A method and apparatus that includes a smoothing process to flatten energy depressions in the low-range signal, followed by frequency shifting and gain adjustment to generate high-range signals, ensuring the energy levels match the original high-range signal, thereby preventing auditory degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SBR (Spectral Band Replication) is used to generate high-range components from low-range signals, then audio quality is improved by expanding the frequency band, but energy depressions in the low-range signal cause auditory degradation in the generated high-range signal
Solution Approach 1:
The patent applies preliminary action by performing smoothing processing on the low-range signal before using it to generate high-range components. The smoothing section pre-processes the low-range signal to eliminate energy depressions, ensuring that when the signal is later used for high-range generation through frequency shifting, the resulting high-range signal does not contain auditory degradation artifacts.
Solution Approach 2:
The patent introduces an intermediary element - the smoothing section - that acts as a mediator between the low-range signal and the high-range signal generation process. This intermediary processes the low-range signal to remove energy depressions before the signal is used to generate high-range components, thereby preventing the transmission of degradation artifacts to the final output.
2Manufacturing precision
If gain adjustment is performed to match energy levels between frequency-shifted signals and target high-range signals, then energy matching is achieved, but energy depressions are transferred to the high-range signal causing auditory degradation
Solution Approach 1:
The patent performs gain adjustment as a preliminary action before frequency shifting. By calculating the appropriate gain based on the ratio between average energy and target energy, and applying this gain to the low-range signal before frequency shifting, the patent ensures that energy matching is achieved without transferring energy depression patterns to the high-range signal.
Solution Approach 2:
The patent applies partial action by selectively adjusting the gain of specific frequency components in the low-range signal. Rather than uniformly processing all frequencies, the gain adjustment is applied specifically to components that will be frequency-shifted to the high-range, with the gain value carefully calculated to achieve energy matching while avoiding the transfer of energy depression artifacts.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method, system, and computer program product for processing an encoded audio signal is described. In one exemplary embodiment, the system receives an encoded low-frequency range signal and encoded energy information used to frequency shift the encoded low-frequency range signal. The low-frequency range signal is decoded and an energy depression of the decoded signal is smoothed. The smoothed low-frequency range signal is frequency shifted to generate a high-frequency range signal. The low-frequency range signal and high-frequency range signal are then combined and outputted.