ENCODING DEVICE AND DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an encoding device and a decoding device capable of performing encoding with high compressibility and decoding wide-band frequency spectra. SOLUTION: The encoding device (200) includes an MDCT unit (202) that transforms an input signal in a time domain into a frequency spectrum, a BWE encoding unit (204) that generates extension data which prescribes a higher frequency spectrum at a higher frequency than a lower frequency spectrum included in the converted frequency spectrum by reference to the low frequency spectrum, and an encoded data stream generating unit (205) that encodes to output the lower frequency spectrum and the extension information. The BWE encoding unit (204) generates as the extension information a first parameter which prescribes a lower subband which is to be copied as the higher frequency spectrum from among a plurality of the lower subbands which form the lower frequency spectrum obtained by the MDCT unit (202) and a second parameter which prescribes a gain of the lower subband after being copied. COPYRIGHT: (C)2007,JPO&INPIT