| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an encoding device encoding an audio signal with a high compression rate and a decoding device decoding wideband frequency spectral information. <P>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 refers to a lower frequency spectrum included in the transformed frequency spectrum to generate extension information which specifies a higher frequency spectrum at a higher frequency, and an encoded data stream generating unit 205 that encodes and outputs the lower frequency spectrum and the extension information. The BWE encoding unit 204 generates as the extension information a first parameter which specifies 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 specifies a gain of the lower subband after being copied. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
