Hierarchical coding method and system based on audio attention

Abstract

The invention relates to the technical field of audio coding, in particular to hierarchical coding method and system based on audio attention. The hierarchical coding method comprises a core layer coding step and an extension layer coding step, and specifically comprises the following steps of: firstly, preprocessing an input signal and coding a core layer and an extension layer, wherein the extension layer is used for dividing sub-bands of the preprocessed signal, calculating an attention value of each sub-band, preferentially extracting the sub-band with largest sub-band attention according to the attention values, and quantifying and coding on the sub-band. The hierarchical coding system comprises a preprocessing module, a core layer coding module, a residual mapping module, a sub-band dividing module, an attention calculating module, a sub-band bit distributing module based on the attention and a quantifying / coding module. The invention preferentially codes the sub-band with high attention and aims at the defect that the quality of an attention sound source is increased step by step, thereby realizing high-efficiency gradable audio coding based on the attention.

Description

technical field [0001] The invention relates to the technical field of audio coding, in particular to a hierarchical coding method and system based on audio attention. Background technique [0002] In the security monitoring system, different clients have different restrictions and requirements, and different monitoring terminals and network systems are used to provide different service qualities. The heterogeneous security monitoring network leads to frequent fluctuations in network bandwidth, making the system unable to provide optimal streams for various clients. Scalable coding technology is an effective means to solve this problem. It divides the code stream into a core layer and multiple enhancement layers. The core layer guarantees the lowest reconstruction quality of the signal, and the enhancement layer improves the SNR or expands the The method gradually improves the reconstruction quality. The more enhancement layers received, the higher the decoding sound quali...

AI Technical Summary

Problems solved by technology

Traditional scalable coding is usually aimed at the perceptual characteristics of the human ear, based on the sub-band signal energy or signal-to-masking ratio as the basis for the bit rate allocation strategy, and the audio signals of concern in the security monitoring environment often have high energy, rapid energy changes and Features such as rapid changes in orientation, based on perceptual characteristics such as human ear masking, may cause low-energy but rapidly-changing audio sources of interest to be allocated fewer coding bits, resulting in increased quantization noise and reduced sound quality of the audio source of interest.

This has become an obstacle to improving the quality of audio coding for security monitoring

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