DPCM,由于语音信号的相邻抽样点之间有一定的幅度关联性，所以，可根据以前时刻的样值来预测现时刻的样值，只要传预测值和实际值之差，而不需要每个样值都传输。这种方法就是预测编码。-DPCM, as a result of voice signals between adjacent sampling rate of a certain relevance, we can kind of time based on previous values to predict the kind of value are at all times, as long as the predictive value and the mass difference between the actual value, without the need for each transmission sample values. This method is predictive coding.