VOICE CODING DEVICE, VOICE DECODING DEVICE, VOICE CODING METHOD, VOICE DECODING METHOD, VOICE CODING PROGRAM AND VOICE DECODING PROGRAM

摘要

voice coding device, voice decoding device, voice coding method, voice decoding method, voice coding program and voice decoding program. A linear prediction coefficient of a signal represented in a frequency domain is represented by performing linear prediction analysis in the frequency direction using a covariance method or a self-correlation method. After the filter resistance of the obtained linear prediction coefficient is adjusted, the filtering is performed in the frequency direction on the signal using the adjusted coefficient, thus the temporal envelope of the signal is transformed. This reduces pre-echo and post-echo occurrence and improves the subjective quality of the decoded signal without significantly increasing the bit rate in a frequency domain band extension technique represented by sbr.