AUDIO DECODING DEVICE, AUDIO CODING DEVICE, AUDIO DECODING METHOD, AUDIO CODING METHOD, AUDIO DECODING PROGRAM, AND AUDIO CODING PROGRAM

摘要

An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions. An audio decoding device which decodes a coded audio signal and outputs an audio signal comprises: a coded series analysis unit that analyzes a coded series which contains the coded audio signal; an audio decoding unit that receives from the coded series analysis unit the coded series which contains the coded audio signal and decodes same, obtaining an audio signal; a temporal envelope shape establishment unit that receives information from the coded series analysis unit and/or the audio decoding unit, and, on the basis of the information, establishes a temporal envelope shape of the decoded audio signal; and a temporal envelope correction unit that, on the basis of the temporal envelope shape which is established with the temporal envelope shape establishment unit, corrects the temporal envelope shape of the decoded audio signal and outputs same.

主权项

1. A speech decoding device that decodes an encoded speech signal to output a speech signal, the speech decoding device comprising:
a code sequence demultiplexer that divides a code sequence including the encoded speech signal into at least a code sequence including encoded information of a low frequency signal of the speech signal and a code sequence including encoded information of a high frequency signal of the speech signal; a low frequency decoder that receives from the code sequence demultiplexer and decodes the code sequence including encoded information of the low frequency signal to obtain a low frequency signal; a high frequency decoder that receives first information from at least one of the code sequence demultiplexer and the low frequency decoder and generates a high frequency signal based on the first information; a high frequency temporal envelope shape determiner that receives second information from at least one of the code sequence demultiplexer, the low frequency decoder and the high frequency decoder and determines a temporal envelope shape of the generated high frequency signal based on the second information; a high frequency temporal envelope modifier that modifies the temporal envelope shape of the generated high frequency signal based on the temporal envelope shape determined by the high frequency temporal envelope shape determiner and outputs the modified high frequency signal; and a low frequency/high frequency signal combiner that receives the low frequency signal from the low frequency decoder, receives the high frequency signal, whose temporal envelope shape is modified, from the high frequency temporal envelope modifier and combines the low frequency signal and the high frequency signal, whose temporal envelope shape is modified, to obtain a speech signal to be output.