| 摘要 |
PROBLEM TO BE SOLVED: To encode general acoustic signal with high quality by using MIDI data, and reproduce this by using a general MIDI sound source. SOLUTION: A fundamental frequency, a '1/3 semitone' higher intermediate frequency, and a '1/3 semitone' lower intermediate frequency corresponding to note numbers prepared by a MIDI sound source are defined on the frequency axis. Plural unit sections are set on the time base, and an original acoustic signal are encoded in each unit section. Encoding is performed by expressing the original acoustic signals by sign data as sets of periodic signals with the defined fundamental frequency or the medium frequencies. At the time of decoding, the MIDI sound source is prepared, and the encoded data showing the fundamental frequency is to be reproduced from the MIDI sound source as it is, and the encoded data showing the intermediate frequencies are reproduced by correcting the MIDI sound source by a '1/3 semitone'. |
