Audio waveform reproduction apparatus
First Claim
1. An audio waveform reproduction apparatus, comprising:
- a storage means for storing waveform data representing an audio waveform;
a reproduction tempo information input means for inputting reproduction tempo information expressing a tempo for a time when the audio waveform is reproduced;
a first time function production means for producing first information (TP) that is a time function based on the reproduction tempo information;
a second time function production means for producing second information (PP) that is a time function based on time axis compression/expansion information (TR);
a time axis compression/expansion information production means for comparing the first information and the second information and calculating the time axis compression/expansion information (TR) towards matching the temporal change of the second information with the temporal change of the first information; and
a time axis compression/expansion processing means for subjecting the audio waveform to time axis compression/expansion processing based on the time axis compression/expansion information (TR) to produce a reproduction audio waveform;
wherein the first information (TP) and the second information (PP) represent positions on a common axis.
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Abstract
The present invention relates to an audio waveform reproduction apparatus for reproducing a recorded audio waveform at a reproduction tempo that can be specified as desired, and its object is to achieve that the reproduction does not deviate from the tempo when performed at a tempo that is different from the tempo at the time of recording of the audio waveform. The audio waveform reproduction apparatus includes a storage means for storing waveform data of the audio waveform, an input means for inputting reproduction tempo information, a first information production means for producing first information (TP) that is a time function based on the reproduction tempo information, a second information production means for producing second information (PP) that is a time function based on time axis compression/expansion information (TR), a compression/expansion information production means for comparing the first information and the second information and calculating the time axis compression/expansion information (TR) towards matching the temporal change of the second information with the temporal change of the first information, and a time axis compression/expansion processing means for performing time axis compression/expansion processing based on the time axis compression/expansion information (TR) to produce a reproduction audio waveform, wherein the first information (TP) and the second information (PP) represent positions on a common axis.
50 Citations
31 Claims
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1. An audio waveform reproduction apparatus, comprising:
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a storage means for storing waveform data representing an audio waveform;
a reproduction tempo information input means for inputting reproduction tempo information expressing a tempo for a time when the audio waveform is reproduced;
a first time function production means for producing first information (TP) that is a time function based on the reproduction tempo information;
a second time function production means for producing second information (PP) that is a time function based on time axis compression/expansion information (TR);
a time axis compression/expansion information production means for comparing the first information and the second information and calculating the time axis compression/expansion information (TR) towards matching the temporal change of the second information with the temporal change of the first information; and
a time axis compression/expansion processing means for subjecting the audio waveform to time axis compression/expansion processing based on the time axis compression/expansion information (TR) to produce a reproduction audio waveform;
wherein the first information (TP) and the second information (PP) represent positions on a common axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
wherein the waveform data of the storage means is PCM data, which are a time series of sampled amplitude data of the audio waveform; and
wherein the time axis compression/expansion processing means subjects the PCM data to time axis compression/expansion processing based on the time axis compression/expansion information (TR) to produce the reproduction audio waveform.
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3. An audio waveform reproduction apparatus as recited in claim 2, wherein the common axis represents positions of the PCM data in terms of addresses.
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4. An audio waveform reproduction apparatus as recited in claim 3:
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wherein the storage means also stores original tempo information, which is the tempo of the audio waveform at the time of recording;
wherein the reproduction tempo information is period information of a period corresponding to the reproduction tempo; and
wherein the first time function production means calculates the amount of change of addresses per predetermined number of periods of reproduction tempo information based on the original tempo information, and produces the first information, which is a time function representing positions of the PCM data, based on the amount of change of addresses and the reproduction tempo information.
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5. An audio waveform reproduction apparatus as recited in claim 4:
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wherein the first time function production means calculates the amount of change of addresses per one period of the reproduction tempo information, and produces the first information (TP), which is a time function representing positions of the PCM data, which advance successively by the amount of change every time the reproduction tempo information is input;
wherein the second time function production means produces the second information (PP), which is a time function representing positions of the PCM data, which advance successively by the time axis compression/expansion information (TR) for each reproduction sampling period; and
wherein the time axis compression/expansion information production means compares the first information (TP) and the second information (PP) for each reproduction tempo information to calculate the time axis compression/expansion information (TR), which is the advance amount towards matching of the first information and the second information.
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6. An audio waveform reproduction apparatus as recited in claim 1:
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wherein the waveform data of the storage means are analysis data analyzing and representing the audio waveform; and
wherein the time axis compression/expansion processing means subjects the analysis data to time axis compression/expansion processing based on the time axis compression/expansion information (TR) to produce the reproduction audio waveform.
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7. An audio waveform reproduction apparatus as recited in claim 6, wherein the common axis represents positions in terms of virtual addresses representing the time axis of the audio waveform.
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8. An audio waveform reproduction apparatus as recited in claim 7:
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wherein the storage means also stores original tempo information, which is the tempo of the audio waveform at the time of recording;
wherein the reproduction tempo information is period information of periods corresponding to the reproduction tempo; and
wherein the first time function production means calculates the amount of change of addresses per predetermined number of periods of reproduction tempo information, based on the original tempo information, and produces the first information, which is a time function representing positions in terms of the virtual addresses, based on the amount of change of addresses and the reproduction tempo information.
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9. An audio waveform reproduction apparatus as recited in claim 8:
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wherein the first time function production means calculates the amount of change of addresses per one period of the reproduction tempo information and produces the first information (TP), which is a time function representing positions in terms of the virtual addresses, which advance successively by the amount of change every time the reproduction tempo information is input;
wherein the second time function production means produces the second information (PP), which is a time function representing positions in terms of the virtual addresses, which advance successively by the time axis compression/expansion information (TR) for each reproduction sampling period; and
wherein the time axis compression/expansion information production means compares the first information (TP) and the second information (PP) for each reproduction tempo information to calculate the time axis compression/expansion information (TR), which is the advance amount towards matching the first information with the second information.
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10. An audio waveform reproduction apparatus as recited in any of claims 1 to 9, wherein the production of the audio waveform with the time axis compression/expansion processing means is repeated from the start position of the audio waveform, at a predetermined repetition period that is based on the reproduction tempo.
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11. A system for audio waveform reproduction, comprising:
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memory for storing audio waveform data representing an original audio waveform;
an actuator for entering reproduction tempo information representing a reproduction tempo; and
a processor programmed for generating first information (TP), TP representing both a time function based on the reproduction tempo information and a position on a common axis, generating second information (PP), PP representing both a time function based on time axis compression/expansion information (TR) and a position on the common axis, comparing TP and PP, computing a new value for TR for matching temporal changes of PP to temporal changes of TP, and subjecting the stored audio waveform data to time axis compression/expansion processing based on TR to produce a reproduction audio waveform. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
the stored audio waveform data comprising PCM data representing a time series of amplitude data sampled from the original audio waveform; and
the processor further programmed for performing time axis compression/expansion processing based on TR on the PCM data to produce the reproduction audio waveform.
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13. A system for audio waveform reproduction as recited in claim 12, the common axis representing address positions of the PCM data.
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14. A system for audio waveform reproduction as recited in claim 13:
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the memory for further storing original tempo information;
the reproduction tempo information comprising period information of a period corresponding to the reproduction tempo; and
the processor further programmed for calculating an address change amount per a predetermined number of periods of the reproduction tempo information based on the original tempo information, and generating TP, which is a time function representing positions of the PCM data, based on the address change amount and the reproduction tempo information.
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15. A system for audio waveform reproduction as recited in claim 14, the processor further programmed for:
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calculating the address change amount per one period of the reproduction tempo information and generating TP, which is a time function representing positions of the PCM data that advances successively by the address change amount every time the reproduction tempo information is entered;
generating PP, which is a time function representing positions of the PCM data that advances successively by an amount equal to TR at each reproduction sampling period; and
comparing TP and PP at each period of the reproduction tempo information to calculate TR, which is an advance amount for matching of TP and PP.
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16. A system for audio waveform reproduction as recited in claim 11:
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the stored waveform data comprising analysis data representing the original audio waveform; and
the processor further programmed for performing time axis compression/expansion processing based on TR on the analysis data to produce the reproduction audio waveform.
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17. A system for audio waveform reproduction as recited in claim 16, the common axis representing virtual address positions on the time axis of the original audio waveform.
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18. A system for audio waveform reproduction as recited in claim 17:
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the memory for further storing original tempo information;
the reproduction tempo information comprising period information of periods corresponding to the reproduction tempo; and
the processor is further programmed for calculating an address change amount per predetermined number of periods of the reproduction tempo information based on the original tempo information, and generating TP, which is a time function representing positions of the virtual addresses, based on the address change amount and the reproduction tempo information.
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19. A system for audio waveform reproduction as recited in claim 18, the processor further programmed for:
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calculating an address change amount per one period of the reproduction tempo information and generating TP, which is a time function representing positions of the virtual addresses that advance successively by the address change amount every time the reproduction tempo information is entered;
generating PP, which is a time function representing positions of the virtual addresses that advance successively by an amount equal to TR at each reproduction sampling period; and
comparing TP and PP at each period of the reproduction tempo information to calculate TR, which is an advance amount for matching TP and PP.
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20. A system for audio waveform reproduction as recited in claim 11, wherein generation of the reproduction audio waveform is repeated from a start position of the stored audio waveform at a predetermined repetition period that is based on the reproduction tempo.
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21. A method for audio waveform reproduction, the method comprising the steps of:
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storing audio waveform data representing an original audio waveform;
entering reproduction tempo information representing a reproduction tempo;
generating first information (TP), TP representing both a time function based on the reproduction tempo information and a position on a common axis;
generating second information (PP), PP representing both a time function based on time axis compression/expansion information (TR) and a position on the common axis;
comparing TP and PP;
computing a new value for TR for matching temporal changes of PP to temporal changes of TP; and
subjecting the stored audio waveform data to time axis compression/expansion processing based on TR to produce a reproduction audio waveform. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
the stored audio waveform data comprising PCM data representing a time series of amplitude data sampled from the original audio waveform; and
the method further including the step of performing time axis compression/expansion processing based on TR on the PCM data to produce the reproduction audio waveform.
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23. A method for audio waveform reproduction as recited in claim 22, the common axis representing address positions of the PCM data.
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24. A method for audio waveform reproduction as recited in claim 23, the reproduction tempo information comprising period information of a period corresponding to the reproduction tempo, the method further including the steps of:
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storing original tempo information;
calculating an address change amount per a predetermined number of periods of the reproduction tempo information based on the original tempo information; and
generating TP, which is a time function representing positions of the PCM data, based on the address change amount and the reproduction tempo information.
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25. A method for audio waveform reproduction as recited in claim 24, the method further including the steps of:
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calculating the address change amount per one period of the reproduction tempo information and generating TP, which is a time function representing positions of the PCM data that advances successively by the address change amount every time the reproduction tempo information is entered;
generating PP, which is a time function representing positions of the PCM data that advances successively by an amount equal to TR at each reproduction sampling period; and
comparing TP and PP at each period of the reproduction tempo information to calculate TR, which is an advance amount for matching of TP and PP.
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26. A method for audio waveform reproduction as recited in claim 21, the stored waveform data comprising analysis data representing the original audio waveform, the method further including the step of performing time axis compression/expansion processing based on TR on the analysis data to produce the reproduction audio waveform.
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27. A method for audio waveform reproduction as recited in claim 26, the common axis representing virtual address positions on the time axis of the original audio waveform.
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28. A method for audio waveform reproduction as recited in claim 27, the reproduction tempo information comprising period information of periods corresponding to the reproduction tempo, the method further including the steps of:
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storing original tempo information;
calculating an address change amount per predetermined number of periods of the reproduction tempo information based on the original tempo information; and
generating TP, which is a time function representing positions of the virtual addresses, based on the address change amount and the reproduction tempo information.
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29. A method for audio waveform reproduction as recited in claim 28, the method further including the steps of:
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calculating an address change amount per one period of the reproduction tempo information and generating TP, which is a time function representing positions of the virtual addresses that advance successively by the address change amount every time the reproduction tempo information is entered;
generating PP, which is a time function representing positions of the virtual addresses that advance successively by an amount equal to TR at each reproduction sampling period; and
comparing TP and PP at each period of the reproduction tempo information to calculate TR, which is an advance amount for matching TP and PP.
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30. A method for audio waveform reproduction as recited in claim 21, wherein generation of the reproduction audio waveform is repeated from a start position of the stored audio waveform at a predetermined repetition period that is based on the reproduction tempo.
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31. A method for audio waveform reproduction as recited in claim 21, further including the step of multiplying TR by a tempo adjustment coefficient to produce a corrected value TR and an adjusted reproduction tempo.
Specification