| 摘要 |
PROBLEM TO BE SOLVED: To provide a spectrum coding apparatus capable of performing coding at a low bit rate with high quality. SOLUTION: The apparatus includes: a frequency domain transformation part 403 for obtaining a first spectrum with a frequency k in a band of 0≤=k<FL; a frequency domain transformation part 404 for obtaining a second spectrum with a frequency k in a band of 0≤k<FH; an internal state setting part 405 and a filtering part 406, in which an estimation spectrum of the second spectrum with a frequency k in a band of FL≤k<FH is created based on a pitch coefficient by using the first spectrum; and a sub-band dividing part 409, a sub-band selecting part 412, a search part 407 and a pitch coefficient-setting part 408, in which the second spectrum is divided into a plurality of sub-bands with a frequency k in a band of FL≤k<FH, the second spectrum is estimated by calculating the pitch coefficient which makes an error minimum between the second spectrum and the estimation spectrum, for each sub-band, and the pitch coefficient is coded for each sub-band. COPYRIGHT: (C)2011,JPO&INPIT
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