Voice analysis/synthesis apparatus and program
AssigneeCasio Computer Co., Ltd.
InventorMasaru Setoguchi
Life of this patent
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Abstract
An FFT unit performs an FFT process on high-frequency-eliminated, pitch-shifted voice data for one frame. A time scaling unit calculates a frequency amplitude, a phase, a phase difference between the present and immediately preceding frames, and an unwrapped version of the phase difference for each channel from which the frequency component was obtained by the FFT, detects a reference channel based on a peak one of the frequency amplitudes, and calculates the phase of each channel in a synthesized voice based on the reference channel, using results of the calculation. An IFFT unit processes each frequency component in accordance with the calculated phase, performs an IFFT process on the resulting frequency component, and produces synthesized voice data for one frame.
Claims10
A voice analysis/synthesis apparatus that analyses a first voice waveform and synthesizes a second voice waveform using a result of the analysis, the apparatus comprising:
- a frequency analyzing unit for analyzing the frequencies of the first voice waveform in units of a frame and for extracting a frequency component for each frequency channel;
- a phase calculating unit for calculating a phase difference in a frame between the first and second voice waveforms, the frame preceding the present frame by a predetermined number of frames, with a predetermined one of the frequency channels as a standard, and for calculating a phase of the second voice waveform in the present frame by referring to the frequency components each extracted by the frequency analyzing unit for a respective frequency channel, using the phase difference;
- and
- a voice synthesizing unit for extracting a formant of the first voice waveform from the frequency components each extracted from a respective frequency channel by the frequency analyzing unit, for operating the extracted frequency components to shift the extracted formant, for converting the frequency component for each frequency channel in accordance with the phase calculated by the phase calculating unit, and for synthesizing the second voice waveform in units of a frame, using the converted frequency components.
A computer readable program for a analysis/synthesis apparatus that analyses a first voice waveform and synthesizes a second voice waveform using a result of the analysis, the program causing a computer to perform the following functions of
- analyzing the frequencies of the first voice waveform in units of a frame and extracting a frequency component for each frequency channel;
- calculating a phase difference in a frame between the first and second voice waveforms, the frame preceding the present frame by a predetermined number of frames, with a predetermined one of the frequency channels as a standard, and calculating a phase of the second voice waveform in the present frame by referring to the frequency components each extracted by the frequency analyzing function for a respective frequency channel, using the phase difference;
- and
- extracting a formant of the first voice waveform from the frequency components each extracted from a respective frequency channel by the frequency analyzing function, operating the extracted frequency components to shift the extracted formant, converting the frequency component for each frequency channel in accordance with the phase calculated by the phase calculating function, and synthesizing the second voice waveform in units of a frame, using the converted frequency components.
Dependencies are inferred from the claim text.