Patent ID: 8655649

Claim:
A speech decoding device for decoding an encoded speech signal, the speech decoding device comprising: a processor; a bit stream separator executed by the processor to separate a bit stream, which includes the encoded speech signal, into an encoded bit stream and temporal envelope supplementary information, wherein the bit stream is received from outside the speech decoding device; a core decoder executed by the processor to decode the encoded bit stream obtained by the bit stream separator in order to obtain a low frequency component; a frequency transformer executed by the processor to transform the low frequency component obtained by the core decoder into a spectral region; a high frequency generator executed by the processor to generate a high frequency component by copying, from a low frequency band to a high frequency band, the low frequency component transformed into the spectral region by the frequency transformer; a high frequency adjuster executed by the processor to adjust the high frequency component generated by the high frequency generator in order to generate an adjusted high frequency component; a low frequency temporal envelope analyzer executed by the processor to analyze the low frequency component transformed into the spectral region by the frequency transformer in order to obtain temporal envelope information; a supplementary information converter executed by the processor to use a predetermined table in order to convert the temporal envelope supplementary information into a parameter for adjusting the temporal envelope information; a temporal envelope adjuster executed by the processor to adjust the temporal envelope information obtained by the low frequency temporal envelope analyzer in order to generate a gain coefficient, wherein the temporal envelope adjuster uses the parameter and the temporal envelope information to generate the gain coefficient; and a temporal envelope shaper executed by the processor to shape to temporal envelope of the adjusted high frequency component, using the gain coefficient.