Yamaha Corporation

Bee Suan Ong

Sebastian Streich

Keita Arimoto

Takuya Fujishima

Jordi Bonada

Maarten De Boer

In an audio analysis apparatus, a component acquirer acquires a component matrix composed of an array of component values, columns of the component matrix corresponding to the sequence of unit periods of an audio signal and rows of the component matrix corresponding to a series of unit bands of the audio signal arranged in a frequency-axis direction. A difference generator generates a plurality of shift matrices each obtained by shifting the columns of the component matrix in the time-axis direction with a different shift amount, and generates a plurality of difference matrices each composed of an array of element values in correspondence to the plurality of the shift matrices, the element value representing a difference between the corresponding component values of the shift matrix and the component matrix. A feature amount extractor generates a tonal feature amount including a plurality of series of feature values corresponding to the plurality of difference matrices, one series of feature values corresponding to the series of unit bands of the difference matrix, one feature value representing a sequence of element values arranged in the time-axis direction at the corresponding unit band of the difference matrix.

Audio analysis apparatus

Character value of a sound signal is extracted for each unit portion, and degrees of similarity between the character values of the individual unit portions are calculated and arranged in a matrix configuration. The matrix has arranged in each column the degrees of similarity acquired by comparing, for each of the unit portions, the sound signal and a delayed sound signal obtained by delaying the sound signal by a time difference equal to an integral multiple of a time length of the unit portion, and it has a plurality of the columns in association with different time differences. Repetition probability is calculated for each of the columns corresponding to the different time differences in the matrix. A plurality of peaks in a distribution of the repetition probabilities are identified. The loop region in the sound signal is identified by collating a reference matrix with the degree of similarity matrix.

Sound signal processing apparatus and method

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.

Music analysis apparatus

For each of a plurality of music pieces, a storage device stores respective tone data of a plurality of fragments of the music piece and respective musical character values of the fragments. Similarity determination section calculates a similarity index value indicative of a degree of similarity between the character values of each of the fragments of a main music piece and the character values of each individual fragment of a plurality of sub music pieces. Each of the similarity index values calculated for the fragments of each of the sub music pieces can be adjusted in accordance with a user's control. Processing section processes the tone data of each of the fragments of the main music piece on the basis of the tone data of any one of the fragments of the sub music pieces of which the similarity index value indicates sufficient similarity.

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Rijswijk, Netherlands

Bee Suan Ong