| 摘要 |
PROBLEM TO BE SOLVED: To provide a voice coding device obtaining an excellent voice quality even with a low bit rate. SOLUTION: A mode discrimination circuit 370 discriminates a mode based on a past quantization gain of an adaptive code book, and s voice source quantization circuit 350 combines a code vector stored in code books 351, 352 together quantizing amplitude or polarity of plural pieces of pulses with respective plural shift amounts timewise shifting prescribed decided pulse positions to retrieve in the case of a prescribed mode, and selects the combination of the code vector and the shift amount minimizing a distortion with an input voice, and a gain quantization circuit 366 quantizes a gain by using a gain code book 380. |
