Time-axis compression/expansion method and apparatus for multichannel signals

A time-axis compression/expansion apparatus for time-axis compressing/expanding a multichannel signal formed of a plurality of channel signals at a specified compression/expansion rate, comprising:

• a plurality of waveform segment-cutting sections that each sequentially cut out waveform segments from a corresponding one of said channel signals;
• a cutting starting point-determining section that determines a cutting starting point of a leading end portion of a waveform segment of the cut out waveform segments following each preceding waveform segment of the cut out waveform segments, commonly between said channel signals, based on two portions of a waveform of a synthesized signal formed by synthesizing said channel signals within a range of a predetermined search starting point to a predetermined search ending point of said waveform of said synthesized signal, said two portions corresponding to a time period over which cross-fading is to be carried out and being most similar to each other;
• and
• a splicing section that splices together said preceding waveform segment and said following waveform segment cut from each of said channel signals based on the determined cutting starting point, by cross-fading a trailing end portion of said preceding waveform segment and the leading end portion of said following waveform segment.

A storage medium storing a program which can be executed by a computer, for realizing a time-axis compression/expansion method for time-axis compressing/expanding a multichannel signal formed of a plurality of channel signals at a specified compression/expansion rate, the program comprising:

• a waveform segment-cutting module that sequentially cuts out waveform segments from each of said channel signals;
• a cutting starting point-determining module that determines a cutting starting point of a leading end portion of a waveform segment of the cut out waveform segments following each preceding waveform segment of the cut out waveform segments, commonly between said channel signals, based on two portions of a waveform of a synthesized signal formed by synthesizing said channel signals within a range of a predetermined search starting point to a predetermined search ending point of said waveform of said synthesized signal, said two portions corresponding to a time period over which cross-fading is to be carried out and being most similar to each other;
• and
• a splicing module that splices together said preceding waveform segment and said following waveform segment cut from each of said channel signals based on the determined cutting starting point, by cross-fading a trailing end portion of said preceding waveform segment and the leading end portion of said following waveform segment.