Time-series signal analysis method and acoustic signal encoding method

摘要

PROBLEM TO BE SOLVED: To perform more accurate frequency analysis to a time-series signal, and to encode an original acoustic sound signal with high quality. SOLUTION: A time-series signal is inputted (S1), and is divided into unit sections (S2). A function group consisting of plural periodical functions is defined (S3), and a sectional signal X is extracted from one unit section and this is defined as a 1st difference signal S(1) (S4). Such a periodic function as a correlation value E to the sectional signal X is the highest and a correlation value EE to a jth difference signal S(j) that is proximate to the correlation value E is selected from the group of functions as a jth element function (S6); this element function is excluded from the group of functions (S7); a content signal G(j) given by the product of the element function and the correlation value EE is obtained; a new difference signal S(j+1) is obtained by subtracting the content signal G(j) from the difference signal S(j) (S8); and by repeating such processing, MIDI data according to J-pieces of content signals obtained from each section are generated.