PERIODIC-COMBINED-ENVELOPE-SEQUENCE GENERATION DEVICE, PERIODIC-COMBINED-ENVELOPE-SEQUENCE GENERATION METHOD, PERIODIC-COMBINED-ENVELOPE-SEQUENCE GENERATION PROGRAM AND RECORDING MEDIUM

摘要

An envelope sequence is provided that can improve approximation accuracy near peaks caused by the pitch period of an audio signal. A periodic-combined-envelope-sequence generation device according to the present invention takes, as an input audio signal, a time-domain audio digital signal in each frame, which is a predetermined time segment, and generates a periodic combined envelope sequence as an envelope sequence. The periodic-combined-envelope-sequence generation device according to the present invention comprises at least a spectral-envelope-sequence calculating part and a periodic-combined-envelope generating part. The spectral-envelope-sequence calculating part calculates a spectral envelope sequence of the input audio signal on the basis of time-domain linear prediction of the input audio signal. The periodic-combined-envelope generating part transforms an amplitude spectral envelope sequence to a periodic combined envelope sequence on the basis of a periodic component of the input audio signal in the frequency domain.

主权项

1. A periodic-combined-envelope-sequence generation device comprising:
a spectral-envelope-sequence calculating part which takes, as an input audio signal, a time-domain audio digital signal in each frame which is a predetermined time segment, and calculates a spectral envelope sequence of the input audio signal on the basis of time-domain linear prediction of the input audio signal; and a periodic-combined-envelope generating part which transforms the spectral envelope sequence to a periodic combined envelope sequence on the basis of a periodic component of the input audio signal in the frequency domain.