Layered Audio Encoding Residual Thresholding
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Solution Overview
Problem
Existing encoding methods, such as traditional ADPCM, result in poor decoding quality when decoders support only low bit rates due to insufficient network bandwidth and poor transmission quality, as they fail to effectively utilize added coded bits.
Innovation Solution
An encoding method that generates a core layer signal and compares residuals with encoding thresholds to produce an enhancement layer, improving decoding quality by ensuring the quality of decoded signals is comparable to low bit rate encoding, even under low bit rate conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If coded bits are added to improve speech/audio signal quality, then encoding quality is improved, but decoding quality deteriorates when decoders support only low bit rates
Solution Approach 1:
The patent segments the encoded signal into multiple layers: a core layer containing essential information for low bit rate decoding, and an enhancement layer containing additional coded bits for high quality decoding. This segmentation allows decoders to selectively process only the core layer when operating at low bit rates, ensuring acceptable decoding quality without requiring the enhancement layer.
Solution Approach 2:
The patent introduces a hierarchical dimension to the encoding structure, organizing coded bits into different layers (core layer and enhancement layer) based on their importance. This dimensional organization enables decoders to operate at different quality levels by selecting which layers to process, resolving the contradiction between encoding quality and low bit rate decoding quality.
2Device complexity
If traditional ADPCM encoding is used, then encoding simplicity is maintained, but decoding quality becomes worse than original signals when extra coded bits are added
Solution Approach 1:
The patent divides the encoded signal into core layer and enhancement layer, where the core layer uses simple ADPCM encoding that can be decoded by basic decoders, while the enhancement layer adds sophisticated processing only when needed. This segmentation maintains encoding simplicity for the core functionality while improving decoding quality when enhancement is available.
Solution Approach 2:
The patent introduces an intermediary structure (the layered organization of coded bits) between the simple ADPCM encoder and the decoder. This intermediary allows the system to maintain backward compatibility with simple decoders while enabling enhanced quality when more capable decoders are used, resolving the contradiction between simplicity and quality.
Data Source
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AI summary
The present invention relates to information processing technologies and discloses an encoding and decoding method and device to solve the poor decoding quality problem. The technical solution of the present invention includes: encoding each sample of an input signal to generate an encoded signal of a core layer; comparing residuals of all or a part of the samples of the input signal with encoding thresholds, where the residuals are generated by core layer encoding, and performing encoding according to comparison results to generate an encoded signal of an enhancement layer; and writing the encoded signal of the core layer and the encoded signal of the enhancement layer into a bitstream to generate an encoded signal of the input signal. Embodiments of the present invention may be applied in the process of encoding and decoding a narrowband, wideband, ultra-wideband, or full-band speech/audio signal by using the adaptive differential pulse code modulation (ADPCM) or pulse code modulation (PCM) encoding method.