Encoding and decoding method for audio processing frame

Abstract

The invention provides encoding and decoding methods for an audio processing framework, wherein, the steps of the encoding method are that: A. a low-frequency stage signal after being preprocessed is firstly selected through PCX / ACELP mode, and the signal is treated with LPC analysis; B. according to the result of selection, the signal enters into the ACELP or the PCX mode for decoding; for the PCX mode, the inputted low frequency signal is treat with LPC aggregate and perceptual weighted process to acquire an LPC residual; then the LPC residual is treated with an extraction of model parameters; finally, a LPC coefficient and the model parameters are all treated with quantization encoding. The decoding steps are that: C. an input code stream acquires an encoding mode, ACELP parameter or PCX parameter via analysis and anti-quantization; D. decoding enters into different decoding branches according to the acquired mode; for the decoding of PCX, a LPC excite signal is synthesized through the model parameters using a synthetic method of a model corresponding to the encoding end, and the signal acquires a final low frequency signal through time domain LPC filter.

Description

technical field [0001] The invention relates to encoding and decoding techniques in signal processing, in particular to an encoding and decoding method used in an audio processing framework. Background technique [0002] The audio codec technology mainly includes the T / F (time / frequency) conversion method that can make good use of the psychoacoustic model, and the method of extracting the parameters of the audio signal model. In the existing audio processing framework, the AAC (Advance Audio Coding, Advanced Audio Coding) framework uses the method of T / F conversion, while AMR-WB+ (Extended Adaptive Multi-rate wideband Codec, multi-bit rate adjustable wideband extended coding Decoding) framework utilizes these two methods at the same time to process different signals differently. [0003] The AMR-WB+ framework includes four parts: preprocessing, TCX / ACELP composite excitation codec, stereo processing, and bandwidth expansion. Wherein, the TCX / ACELP composite excitation codi...

AI Technical Summary

Problems solved by technology

The bit rate range of AMR-WB+ is 6kbps to 48kbps, so in the case of extremely low bit rate, the TCX method directly quantizes the signal spectrum, which will cause a large quantization error to exist in the entire spectrum range of the signal, thus making Subjective quality reduction of final decoded output

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