Title:
WAVEFORM DATA READER
Document Type and Number:
Japanese Patent JP3223560
Kind Code:
B2
Abstract:
PURPOSE: To generate musical tone having a frequency higher than the frequency of a source sound concerning the waveform data reader for an electronic musical instrument to generate musical tone by reading waveform data stored in a DPCM system.
CONSTITUTION: An updated current value address (5. 25) is obtained by adding an address stepping amount (1. 5) to a current value address (3. 75). In this case, the integer parts of addresses before and after update are compared, and the increment amount (step change amount) of the integer part is judged. As the result, when the integer part is increased by 2, for example, two continuous differential value data (D1, D2) are successively read from a DPCM-ROM and successively added to a source integrated value (S1). As the result, an amplitude value (A2) of waveform data corresponding to the updated current value address (5. 25) is generated by interpolating arithmetic from a new integrated value (S3), differential value data (Dh) corresponding to the integer part (5) of the updated current value address, and the decimal part (0. 25) of the updated current value address.
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Inventors:
Kikuji Tanaka
Application Number:
JP7409492A
Publication Date:
October 29, 2001
Filing Date:
March 30, 1992
Export Citation:
Assignee:
CASIO COMPUTER CO.,LTD.
International Classes:
G10H7/00; G10H7/02; (IPC1-7): G10H7/02
Domestic Patent References:
| JP3269597A | ||||
| JP519348A |
Attorney, Agent or Firm:
Yoshiyuki Ohsuga