Audio Encoding of High-Band Tone Components for Better Decoding
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Solution Overview
Problem
Existing audio encoding methods fail to effectively improve the quality of decoded audio signals, particularly in limited bandwidth scenarios.
Innovation Solution
An audio encoding method that includes detecting tone components in high-frequency bands and using noise floor parameters to enhance the encoding process, allowing for more accurate recovery of tone components during decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional audio encoding methods are used, then the encoding process is simple, but the quality of decoded audio signals is insufficient
Solution Approach 1:
The audio signal is segmented into frequency bands (low-band, mid-band, high-band) and further divided into sub-bands. Tone components are separately identified and processed from non-tone components. This segmentation allows the encoder to apply different processing strategies to different parts of the signal, improving decoded quality by preserving important tone characteristics while maintaining encoding efficiency.
Solution Approach 2:
The encoding method changes parameters by detecting tone components and representing them using specific parameters (tone frequency, tone magnitude, tone phase) rather than traditional full-band encoding. The noise floor parameter is introduced to characterize the background level. These parameter changes enable more efficient representation of the audio signal, improving decoded quality while managing complexity.
2Manufacturing precision
If bandwidth extension is performed to improve audio quality, then the decoded audio quality improves, but the accuracy of tone component recovery deteriorates
Solution Approach 1:
The method performs preliminary detection of tone components in the high-band signal before bandwidth extension is applied. By identifying and representing tone components in advance using specific parameters (frequency, magnitude, phase), the encoder preserves tone information that would otherwise be lost or distorted during bandwidth extension. This preliminary action ensures accurate tone recovery in the decoded signal.
Solution Approach 2:
The noise floor parameter acts as an intermediary that characterizes the background energy level in the high-band signal. By separately representing tone components and noise floor, the encoding method creates a more accurate model of the high-band signal structure. This intermediary representation allows the decoder to reconstruct tone components more accurately even when bandwidth extension is performed.
3Measurement precision
If tone components are detected and encoded, then the accuracy of tone component recovery improves, but the encoding complexity increases
Solution Approach 1:
The method extracts tone components from the high-band signal and represents them separately using a compact set of parameters (tone frequency, tone magnitude, tone phase). By taking out only the essential characteristics of tone components rather than encoding the entire high-band signal in detail, the method achieves accurate tone recovery while limiting the increase in encoding complexity to a manageable level.
Data Source
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AI summary
Embodiments of this application disclose an audio encoding and decoding method and an audio encoding and decoding device, to improve quality of a decoded audio signal. The audio encoding method includes: obtaining a current frame of an audio signal, where the current frame includes a high frequency band signal and a low frequency band signal; obtaining a first encoding parameter based on the high frequency band signal and the low frequency band signal; obtaining a second encoding parameter of the current frame based on the high frequency band signal, where the second encoding parameter includes tone component information; and performing bitstream multiplexing on the first encoding parameter and the second encoding parameter, to obtain an encoded bitstream.