| 摘要 |
PROBLEM TO BE SOLVED: To enable reproducing a waveform in which vibrato is applied in natural feeling by performing time base expansion (loop reproduction) of waveform data utilizing a vibrato effect included in waveform data. SOLUTION: A pitch is detected and processed for a waveform data, a pitch data column X(n) is made corresponding to time elapse (S1), an initial value (a) is set to a counter (n) (S2), and an average of pitch data of (n) pieces is calculated (S3). An average X(n) is compared with the next pitch data X(n), it is discriminated that (1/α) X(n)<X(n)<αX is satisfied (S4). When a result is 'Yes', nothing is done, and when a result is 'No' the pitch data X(n) is changed to an average X(n)(S5). Thereby, extraction mistake of pitch detection is compensated. It is discriminated whether compensation is performed until the last part of pitch column data (S6) or not, when a result is 'Yes', low-pass filtering processing is performed. irregular variation is removed, and a pitch data column X(n) smoothly varied is obtained (S7). |
