| 摘要 |
<p>A voice encoding method using a synthesizing filter having a linear prediction coefficient obtained by dividing an input signal into frames of a fixed length and by linearly predicting/analyzing the input signal in units of a frame and comprising driving the synthesizing filter by a periodic signal outputted from an adaptive code book and a pulsating signal outputted from an algebraic structure code book, producing a reproduced signal, and minimizing the difference between the input signal and the reproduced signal to encode a voice, wherein there are prepared an encoding mode 1 using a pitch lag determined from the input signal of the present frame and an encoding mode 2 using a pitch lag determined from the input signal of a past frame. A mode capable of encoding the input signal more precisely with the encoding mode 1 and the encoding mode 2 is determined for each frame so that the encoding is carried out on the basis of the determined mode.</p> |
