Linear prediction speech coding method using spectral energy for quantization mode selection

摘要

A speech signal digitized as successive frames is subjected to analysis-by-synthesis in order to obtain, for each frame, quantization values of synthesis parameters allowing reconstruction of an estimate of the speech signal. The analysis-by-synthesis includes short-term linear prediction of the speech signal in order to determine the quantization values of the coefficients of a short-term synthesis filter. A spectral state of the speech signal is determined from among first and second states such that the signal contains proportionally less energy at the low frequencies in the first state than in the second state, and one or the other of two modes of quantization is applied to obtain the quantization values of the coefficients of the short-term synthesis filter depending on the determined spectral state of the speech signal.