SOUND SIGNAL DOWNMIXING METHOD, SOUND SIGNAL ENCODING METHOD, SOUND SIGNAL DOWNMIXING DEVICE, SOUND SIGNAL ENCODING DEVICE, PROGRAM, AND RECORDING MEDIUM

摘要

This sound signal downmixing method comprises: an inter-channel relation information acquisition step for obtaining an inter-channel correlation value that is a value showing, for each combination of two channels included in N channels, the magnitude of correlation between input sound signals of the two channels, and preceding channel information showing which input sound signal of the two channels is preceding; and a downmixing step which gives, to the input sound signal of each of the channels on the basis of the inter-channel correlation value and the preceding channel information, a smaller weight as correlation with an input sound signal of each channel preceding said channel is larger, and a larger weight as correlation with an input sound signal of a channel following said channel is larger, and performs weighted addition of the input sound signal of the N channels to obtain a downmixing signal. The sum of the weights is normalized to be 1.