| 摘要 |
PURPOSE:To prevent a voice from deteriorating by using a compressed waveform signal as a voice waveform signal with a constant pitch cycle and connecting the remaining voice waveform signal to the compressed waveform signal without compression. CONSTITUTION:An in-frame time-base compressing means 4 sections an input voice waveform 3 into constant-length analytic frames, and pitch cycles in the analytic frames are found by, for example, autocorrelation analysis and utilized to compress voice waveforms in the analytic frames on the time basis, thereby finding a compressed waveform 5. Further, this device is equipped with an in-frame time-base expanding means 15 which expands the compressed waveform 14 into a voice waveform with original analytic frame length by utilizing the pitch cycles 6 after the signal is decoded in analytic frame units. Then a frame which is longer than plural pitches of the input voice waveform is set, a waveform of plural (p) pitches in this frame is compressed into a waveform of less integral (q) pitches, and the remaining voice waveform signal is connected to the compressed waveform with the integral pitch without being compressed. Consequently, even if a transmission error of pitch cycles is generated, its influence stays in the sectio. |
