| 摘要 |
<p>An encoder apparatus capable of encoding spectrum with a high quality at a low bit rate without occurrence of disturbance in the harmonic structure of the spectrum. In the apparatus, an internal status setting part (106) uses a first spectrum S1(k) to set an internal status of a filtering part (107). A pitch coefficient setting part (109) changes a little by a little and outputs the pitch coefficient T. The filtering part (107) calculates, based on the pitch coefficient T, an estimated value S'2(k) of a second spectrum S2(k). A searching part (108) calculates a similarity between S2(k) and S'2(k). Then, a pitch coefficient T' having the maximum similarity as calculated is applied to a filter coefficient calculating part (110), which uses the pitch coefficient T' to obtain a filter coefficient betai.</p> |
