ENCODING METHOD FOR ACOUSTIC SIGNAL

摘要

PROBLEM TO BE SOLVED: To encode a general acoustic with high quality through the use of MIDI data. SOLUTION: An acoustic signal becoming an encoding object is taken in as data and a trigonometric function with high correlation on a signal X in a unit period (d) is selected as a temporary representative periodic function T(n). A reference period r(n) obtained by shifting the unit period (d) by integer (m)-times of the period T(n) is defined. A phase angle θ 1(n) with respect to the temporary representative period function of the signal X in the unit period (d) and a phase angle θ 2(n) with respect to the temporary representative function of a signal Y in the reference period r(n) are obtained. The operation of TT(n)=(m.T(n)-T(n).Δθ (n)/2π)/m is executed by using the difference Δθ(n) of both phase angle so that a period TT(n) is obtained. The period function having the period TT(n) is defined as a formal representative period function and the signal X in the unit period (d) is made to be representative.