Audio coding method and device for optimizing frequency domain noise shaping

Abstract

The invention discloses an audio coding method and device for optimizing frequency domain noise shaping, and belongs to the technical field of audio coding and decoding. The method comprises the following steps: calculating a voice energy entropy of an audio signal according to the audio signal subjected to low-delay improved discrete cosine transform; judging whether the current frame is a non-voice frame or not according to the voice energy entropy of the current frame of the audio signal and a preset threshold value to obtain a non-voice frame audio signal; and after the non-speech frame audio signal is subjected to first-stage split vector quantization of frequency domain noise shaping, not performing second-stage pyramid vector quantization of a frequency domain noise shaping process. By adding a small amount of operation, the frequency of calling the second-stage pyramid vector quantization by the frequency domain noise shaping module is reduced under the condition that the tone quality is almost unchanged, and the total operand of the frequency domain noise shaping module is reduced.

Description

technical field [0001] The present application relates to the field of audio coding and decoding, in particular to an audio coding method and device for optimizing frequency-domain noise shaping. Background technique [0002] In the LC3 Bluetooth audio encoder, Spectral Noise Shaping (SNS for short) is a relatively complex module that consumes more resources. In the experimental test, the average proportion of computing resources consumed by the frequency domain noise shaping module is about 17.77%. [0003] The coding process of the frequency domain noise shaping module includes a scale factor calculation and estimation step, a first-stage split vector quantization step, a second-stage pyramid vector quantization step, a scale factor interpolation step and a spectrum shaping step. Among the above steps, the second stage The pyramid vector quantization step has the highest complexity and the largest amount of computation. However, in the actual audio coding process, especi...

AI Technical Summary

Problems solved by technology

But in the actual audio coding process, especially in the Bluetooth field, the audio signal usually has speech parts and non-speech parts, and the second-stage pyramid vector quantization step is called or not called for the non-speech part. It hardly affects the sound quality, and calling the second-stage pyramid vector quantization step for the non-speech part will increase the computational load of the frequency domain noise shaping module

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