التفاصيل البيبلوغرافية
| العنوان: |
MUSIC ANALYSIS APPARATUS |
| Document Number: |
20110271819 |
| تاريخ النشر: |
November 10, 2011 |
| Appl. No: |
13/081337 |
| Application Filed: |
April 06, 2011 |
| مستخلص: |
In a musical analysis apparatus, a spectrum acquirer acquires a spectrum for each frame of an audio signal representing a piece of music. A beat specifier specifies a sequence of beats of the audio signal. A feature amount extractor divides an interval between the beats into a plurality of analysis periods such that one analysis period contains a plurality of frames, and separates the spectrum of the frames contained in one analysis period into a plurality of analysis bands so as to set a plurality of analysis units in one analysis period in correspondence with the plurality of the analysis bands, such that one analysis unit contains components of the spectrum belonging to the corresponding analysis band. The feature amount extractor further calculates a feature value of each analysis unit based on the components of the spectrum contained in each analysis unit, thereby generating a rhythmic feature amount that is an array of the feature values calculated for the analysis units and that features a rhythm of the piece of music. |
| Inventors: |
ARIMOTO, Keita (Barcelona, ES); Streich, Sebastian (Rijswijk, NL); Ong, Bee Suan (Rijswijk, NL) |
| Assignees: |
YAMAHA CORPORATION (Hamamatsu-Shi, JP) |
| Claim: |
1. A musical analysis apparatus comprising: a spectrum acquisition part that acquires a spectrum for each unit period of an audio signal representing a piece of music; a beat specification part that specifies a sequence of beats of the audio signal along a time axis; and a feature amount extraction part that divides an interval between the beats into a plurality of analysis periods along the time axis of the audio signal such that one analysis period contains a plurality of the unit periods, and that separates the spectrum of the unit periods contained in one analysis period into a plurality of analysis bands on a frequency axis of the audio signal so as to set a plurality of analysis units in one analysis period in correspondence with the plurality of the analysis bands, such that one analysis unit contains components of the spectrum belonging to the corresponding analysis band, wherein the feature amount extraction part includes a feature calculation part for calculating a feature value of each analysis unit based on the components of the spectrum contained in each analysis unit, thereby generating a rhythmic feature amount that is an array of the feature values calculated for the analysis units arranged in the time axis and in the frequency axis and that features a rhythm of the piece of music. |
| Claim: |
2. The musical analysis apparatus according to claim 1, wherein the feature amount extraction part generates a first rhythmic feature amount that features a rhythm of a first audio signal, and generates a second rhythmic feature amount that features a rhythm of a second audio signal, and wherein the musical analysis apparatus further comprises a feature comparison part that calculates a similarity index value indicating similarity between the rhythm of the first audio signal and the rhythm of the second audio signal by comparing the first rhythmic feature amount and the second rhythmic feature amount with each other. |
| Claim: |
3. The musical analysis apparatus according to claim 2, wherein the feature comparison part comprises: a difference calculation part that calculates, for each of the analysis units, an element value corresponding to a difference between each feature value of the first rhythmic feature amount and each feature value of the second rhythmic feature amount; a correction value calculation part that calculates a first correction value of each analysis period based on a plurality of feature values which are obtained in same analysis period of the first audio signal and which correspond to different analysis bands of the same analysis period among feature values of the rhythmic feature amount of the first audio signal, and that calculates a second correction value of each analysis period based on a plurality of feature values which are obtained in same analysis period of the second audio signal and which correspond to different analysis bands of the same analysis period among feature values of the rhythmic feature amount of the second audio signal; a correction part that applies the first correction value of each analysis period generated for the first audio signal and the second correction value of each analysis period generated for the second audio signal to the element value of each analysis period; and an index calculation part that calculates the similarity index value from the element values after being processed by the correction part. |
| Claim: |
4. The musical analysis apparatus according to claim 2, wherein the feature comparison part comprises: a difference calculation part that calculates, for each of the analysis units, an element value corresponding to a difference between each feature value of the first rhythmic feature amount and each feature value of the second rhythmic feature amount; a correction value calculation part that calculates a first correction value of each analysis band of the first audio signal based on a plurality of feature values which belong to same analysis band and which correspond to different analysis periods of the same analysis band among feature values of the rhythmic feature amount of the first audio signal, and that calculates a second correction value of each analysis band of the second audio signal based on a plurality of feature values which belong to same analysis band and which correspond to different analysis periods of the same analysis band among feature values of the rhythmic feature amount of the second audio signal; a correction part that applies the first correction value of each analysis band generated for the first audio signal and the second correction value of each analysis band generated for the second audio signal to the element value of each analysis band; and an index calculation part that calculates the similarity index value from the element values after being processed by the correction part. |
| Claim: |
5. The musical analysis apparatus according to claim 1, wherein the feature amount extraction part comprises: a correction value calculation part that calculates a correction value of each analysis period based on a plurality of feature values which are obtained for same analysis period and which correspond to different analysis bands of the same analysis period among feature values calculated by the feature calculation part; and a correction part that applies the correction value of each analysis period to each feature value of the corresponding analysis period for correcting each feature value. |
| Claim: |
6. The musical analysis apparatus according to claim 1, wherein the feature amount extraction part comprises: a correction value calculation part that calculates a correction value of each analysis band based on a plurality of feature values which are obtained for same analysis band and which correspond to different analysis periods of the same analysis band among feature values calculated by the feature calculation part; and a correction part that applies the correction value of each analysis band to each feature value of the corresponding analysis band for correcting each feature value. |
| Claim: |
7. A musical analysis apparatus comprising: a storage part that stores a rhythmic feature amount for each of a first audio signal representing a piece of music and a second audio signal representing another piece of music, the rhythmic feature amount comprising an array of feature values of analysis units arranged two-dimensionally on a time axis and a frequency axis, each of the analysis units being defined at each of a plurality of analysis periods in the time axis and at each of a plurality of analysis bands in the frequency axis, the plurality of analysis periods being set by dividing an interval between beats of the piece of music such that one analysis period contains spectrum of a plurality of unit periods of the audio signal, the spectrum of one analysis period being separated into a plurality of analysis bands such that one analysis unit defined at one analysis period and at one analysis band contains components of the spectrum, the feature value of one analysis unit representing the components of the spectrum contained in the one analysis unit; and a feature comparison part that calculates a similarity index value indicating similarity between rhythms of the first audio signal and the second audio signal by comparing the respective rhythmic feature amounts of the first audio signal and the second audio signal. |
| Claim: |
8. A machine readable storage medium containing a musical analysis program being executable by a computer to perform processes of: acquiring a spectrum for each unit period of an audio signal representing a piece of music; specifying a sequence of beats of the audio signal along a time axis; dividing an interval between the beats into a plurality of analysis periods along the time axis of the audio signal such that one analysis period contains a plurality of the unit periods; separating the spectrum of the unit periods contained in one analysis period into a plurality of analysis bands on a frequency axis of the audio signal so as to set a plurality of analysis units in one analysis period in correspondence with the plurality of the analysis bands, such that one analysis unit contains components of the spectrum belonging to the corresponding analysis band; calculating a feature value of each analysis unit based on the components of the spectrum contained in each analysis unit; and generating a rhythmic feature amount that is an array of the feature values calculated for the analysis units arranged two-dimensionally in the time axis and the frequency axis and that features a rhythm of the audio signal. |
| Claim: |
9. A data structure representing a rhythmic feature of an audio signal of music sound, the audio signal being composed of a sequence of unit periods each containing a spectrum of the music sound, the data structure comprising an array of feature values of analysis units arranged two-dimensionally on a time axis and a frequency axis, each of the analysis units being defined at each of a plurality of analysis periods in the time axis and at each of a plurality of analysis bands in the frequency axis, the plurality of analysis periods being defined by dividing an interval between beats of the music sound such that one analysis period contains spectrum of a plurality of unit periods of the audio signal, the spectrum of one analysis period being separated into a plurality of analysis bands such that one analysis unit defined at one analysis period and at one analysis band contains components of the spectrum, the feature value of one analysis unit representing the components of the spectrum contained in the one analysis unit. |
| Current U.S. Class: |
84/611 |
| Current International Class: |
10 |
| رقم الانضمام: |
edspap.20110271819 |
| قاعدة البيانات: |
USPTO Patent Applications |