| 摘要 |
PROBLEM TO BE SOLVED: To transmit only one piece of code table code per a frame. SOLUTION: A power calculation part 1 obtains sound power at every frame, and an LPC analysis part 2 obtains an LPC coefficient, and a characteristic vector calculation part 4 obtains an LPC cepstrum coefficient. A vector quantization part 20 makes the code table code answering to a code table vector closest to a characteristic vector of a present frame different from any one of code table vectors of frame codes of past (k-1) pieces of frames among k pieces of code table vectors until k-th vector from the vector close to the characteristic vector of the present frame a frame code. A class function is obtained from the frame codes of the present frame and the past (k-1) pieces of frames. A pitch extraction part 3 obtains a pitch of a sound. A vector inverse quantization part 22 calculates the characteristic vector of the present frame, and an element piece forming part 6 forms a sound element piece from the characteristic vector. A waveform superposition part 7 superposes the sound element piece by the pitch. |
