| 摘要 |
A MIDI-code generating device utilizing a musical instrument for producing a plurality of musical tones which comprise a fundamental tone and a harmonic tone corresponding to the fundamental tone, the fundamental and harmonic tones being discrete frequencies and having different envelope wave-forms, includes a microphone for converting a produced musical tone from the musical instrument into an electrical audio signal, an A/D converter for converting the electrical audio signal into digital signal of wave-form data, a group of band-pass filters for extracting wave-form data having frequency component respectively corresponding to each of the fundamental tones, from wave-form data outputted by the A/D converter, an envelope detection circuit for detecting envelope data of wave-form data extracted by the group of band-pass filters, a memory for storing reference envelope data of the fundamental tone corresponding to the envelope wave-form of each fundamental tone of the musical tones produced by the musical instrument, a fundamental tone decision circuit for comparing envelope data detected by the envelope detection circuit with fundamental tone envelope data stored in the memory, and for deciding on a produced fundamental tone when the musical tone is produced by the musical instrument, and a coding circuit for generating a MIDI-code according to a result of a decision of the fundamental tone decision circuit and the detected envelope data.
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