System and method for dynamically configuring synthesizers

• US 5,444,818 A
• Filed: 12/03/1992
• Issued: 08/22/1995
• Est. Priority Date: 12/03/1992
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lisle, Ronald J.
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): HAFIZ, TARIQ R
• Application Number:
  US07/984,780
• Time in Patent Office: 992 Days
• Field of Search: 381/49, 381/51, 381/46, 395/2, 395/2.1, 395/2.14, 395/2.67, 395/2.69, 395/2.73, 395/2.77, 395/2.87
• US Class Current: 704/258
• CPC Class Codes: G10H 1/0091 Means for obtaining special acoustic effects combined with modulation G10H1/043
• CPC Class Codes: G10H 7/02 in which amplitudes at successive sample points of a tone waveform are stored in one or more memories

Abstract

A system and method are provided for improving quality of sound generated by computerized systems having limited memory. A wavetable synthesizer is implemented wherein data utilized to synthetically generate acoustic waveforms is stored. A plurality of datasets is also generated and stored, each comprised of a digitized acoustic waveform. In response to a MIDI datastream, the system determines if an appropriate stored acoustic sample corresponding thereto resides in the system'"'"'s memory. If so, the system will generate the desired sound utilizing the stored acoustic sample data. If not, the system automatically determines in real time the appropriate wavetable dataset which will generate a sound most closely approximating the acoustic sound. The system thus dynamically reconfigures in real time between wavetable and acoustic sample synthesis, being configured for the former when appropriate acoustic samples are not present.

Claims

1. A computerized method for producing audio signals comprising

storing a first dataset corresponding to a first mode of producing of said audio signals;

generating a datastream defining parameters associated with said producing of said audio signals, including a specified mode from a group comprising said first mode and a second mode;

detecting automatically from said datastream if said specified mode is said first mode of said producing said audio signals; and

producing said audio signals in said first mode with said datastream and said first dataset in response to said detecting said specified mode is said first mode.

2. The method of claim 1 further including

storing of a second dataset corresponding to said second mode of producing said audio signals;

and

producing said audio signals in said second mode with said datastream and said second dataset in response to said detecting said specified mode is said second mode.

3. The method of claim 2 wherein said datastream is a MIDI datastream.

4. The method of claim 3 further comprising

storing alternatively either said first dataset, or said second dataset as a program change having a unique indicator in said datastream associated therewith;

detecting from said datastream said program change;

determining from said detected program change if said first dataset or said second dataset has been stored; and

producing said audio signals in said first mode with said first dataset after said determining when only said first dataset has been stored.

5. The method of claim 4 further including

producing said audio signals in said second mode with said second dataset after said determining when only said second dataset has been stored.

6. The method of claim 1 wherein said first mode is wavetable synthesis mode.

7. The method of claim 6 wherein said second mode is sampling synthesis mode.

8. The method of claim 1 wherein said detecting and said producing are in real time.

9. The method of claim 1 wherein said detecting step is performed by a host system.

10. The method of claim 9 wherein said producing step is performed by a digital signal processor.

11. A computerized system for producing audio signals comprising

means for storing a first dataset corresponding to a first mode of producing said audio signals;

means for generating a datastream defining parameters associated with said producing of said audio signals, including a specified said first mode;

means for detecting from said datastream if said first mode of said producing said audio signals is specified; and

means for producing said audio signals in said first mode with said datastream and said first dataset in response to said detecting said specified first mode.

12. The apparatus of claim 11 further including

means for storing a second dataset corresponding to a second mode of producing said audio signals;

and

means for producing said audio signals in said datastream and said second mode with said second dataset in response to said detecting said specified second mode.

13. The apparatus of claim 12 wherein said datastream is a MIDI datastream.

14. The apparatus of claim 13 further comprising

means for storing alternatively either said first dataset or said second dataset as a program change having a unique indicator in said datastream associated therewith;

means for detecting from said datastream said program change;

means for determining from said detected program change if said first dataset or said second dataset has been stored; and

means for producing said audio signals in said first mode with said first dataset after said determining when only said first dataset has been stored.

15. The apparatus of claim 14 further including

means for producing said audio signals in said second mode with said second dataset after said determining when only said second dataset has been stored.

16. The apparatus of claim 11 wherein said first mode is wavetable synthesis mode.

17. The apparatus of claim 16 wherein said second mode is sampling synthesis mode.

18. The apparatus of claim 11 wherein said detecting and said producing are in real time.

19. The apparatus of claim 11 wherein said detecting step is performed by a host system.

20. The apparatus of claim 19 wherein said producing step is performed by a digital signal processor.

21. A computerized method for producing an audio signal in response to a datastream containing a program indicator;

comprising

storing a first program associated with a sound to be generated in a first mode;

storing a second program associated with a sound to be generated in a second mode;

monitoring said datastream;

selecting either said first program or said second program as a function of said program indicator in said monitored datastream; and

producing said audio signal in response to data in said selected either first program or second program in a corresponding said first mode or said second mode dependent upon whether said first program or said second program is selected, respectively.

22. The method of claim 21 wherein said sound associated with said first program corresponds to a preselected sound type.

23. The method of claim 22 wherein said sound associated with said second program corresponds to the identical said preselected sound type associated with said first program.

24. The method of claim 23 wherein said second program is selected when said program indicator corresponds to said first program.

25. The method of claim 24 wherein said producing of said audio signal is in said second mode from said data in said second program in response to said selecting said second program.

26. The method of claim 22 wherein said first program is selected by default when a sound associated with said second program does not correspond to said preselected sound type associated with said first program.

27. The method of claim 24 wherein said producing of said audio signal is in said first mode from said data in said first program in response to said selecting said first program by default.