| 摘要 |
PURPOSE:To reduce deterioration in sound quality in the case that the amount of encoded information increases. CONSTITUTION:An encoder 8 encodes the composing filter coefficient K from an LPC analyzer 1 and a code A found by a code book searcher 3 according to a speech signal X1 after high frequency components are removed at all times and outputs its result to a terminal 11. A searcher 6, on the other hand, finds a code B from a difference signal DX corresponding to the high frequency components of the speech signal X and outputs it at all times, but a controller 7 outputs the code B to the encoder 8 only when the amount of encoded information is less than a specific value. Therefore, when the amount of encoded information is less than the specific value, the code B is encoded by the encoder 8 together with the composing filter coefficient K and code A, but when the amount of encoded information exceeds the specific value, the code B is not encoded and only the composing filter coefficient K and code A are encoded in this case. |
