| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a musical waveform time stretching device which actualizes high-quality time-base compression and expansion. <P>SOLUTION: An STFFT analysis part 1 performs short-time fast Fourier transformation for a source musical waveform and outputs peak point data and a residual waveform. A beat extraction part 2 extracts beat start timing from the residual waveform. A time stretch part 3 for a waveform which can not be sine wave-synthesized, determines beat start timing after rearrangement according to a specified time stretch rate. At the same time, the residual waveform is divided by intervals of beat start timing and rearranged at positions of beat start timing after the rearrangement. A time stretch part 4 for a waveform which is can be since wave-synthesized, divides the peak point data at intervals of beat start timing, rearranges them for a period sectioned by the beat start timing after the rearrangement, and then sine wave-synthesizes. <P>COPYRIGHT: (C)2004,JPO |
