Speech decoding device, speech decoding method and speech decoding program

摘要

A speech decoding device for decoding an encoded speech signal, wherein the speech decoding device comprises: bitstream separation means for separating a bitstream that includes the speech signal encoded into a stream of encoded bits and supplementary temporary wrapping information, in which the bit stream is received from outside the speech decoding device: central decoding means for decoding the encoded bit stream separated by the bit stream separation means to obtain a component of bit stream Low frequency; frequency transformation means for transforming the low frequency component obtained by the central decoding means into a frequency domain; high frequency generating means for generating a high frequency component by copying the low frequency component transformed in the frequency domain by means of frequency transformation from a low frequency band to a high frequency band; high frequency adjustment means to adjust the high frequency component generated by the high frequency generation means to generate a high frequency component adjusted; low frequency temporary envelope analysis means for analyzing the low frequency component transformed in the frequency domain by the frequency transformation means to obtain information about the temporary envelope; means of converting supplementary information to convert the temporary envelope supplementary information into a parameter to adjust the temporal envelope information; Temporary wrapping adjustment means for adjusting the temporal wrapping information obtained by means of low frequency wrapping time analysis means, using the parameter to generate adjusted wrapping time information, and controlling an increase in the adjusted wrapping time information, of so that the power of the high frequency component in the frequency domain in an SBR envelope time segment is equivalent before and after shaping the temporary envelope, to generate more adjusted temporal envelope information; and means of forming the temporary wrap to form a temporary wrap of the adjusted high frequency component, multiplying the adjusted high frequency component by means of more adjusted wrapping time information.