SPEECH ENCODING DEVICE, SPEECH DECODING DEVICE, SPEECH ENCODING METHOD, SPEECH DECODING METHOD, SPEECH ENCODING PROGRAM AND SPEECH DECODING PROGRAM

摘要

FIELD: information technology.;SUBSTANCE: present invention relates to the means of encoding and decoding a speech signal. A linear prediction coefficient of a signal presented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. Once the filter power of the obtained linear prediction coefficient is corrected, the signal is frequency filtered using the corrected coefficient, thereby forming a signal time envelope. This reduces the occurence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a band extension technique in the frequency domain, represented by a spectral band replication (SBR).;EFFECT: to reduce pre-echo and post-echo and improve the quality of the decoded signal without increasing the bit rate.;5 cl, 50 dwg