Abstract: For the segment class designation the temporal position of segments in two candidate segment classes is used for the stanza/refrain selection by means of a segment class designation means, wherein the highest-order segment class is designated as refrain segment class only when it has a segment following temporally later in the audio piece than the latest segment of the other candidate segment class. With this, segment class labeling with a low error rate is achieved, which can at the same time be implemented with easy effort and is further predestined for automated flow.

Abstract: For changing a segmentation of an audio piece after a segment class assignment, at first a short segment is selected, which has a length shorter than a predetermined minimum length. This short segment is preferably merged with the corresponding successor segment or predecessor segment using information on a segment class membership of the short segment itself, but also the successor segment or the predecessor segment, in order to obtain a changed segmentation of the audio signal. With this, a not over-segmented segment representation of the audio signal is obtained, which further includes all audio information, i.e. is not a representation of the audio piece with holes.

Abstract: An encoded rhythmic pattern has several groups of velocity values, wherein the velocity values are sorted, such that the groups are included in sequence in an encoded rhythmic pattern. Now, the velocity values concentrated at the beginning of the encoded rhythmic pattern have a higher importance for characterizing the rhythmic gist of a piece of music than velocity values included in additional groups of velocity values. By using such an encoded rhythmic pattern, an efficient database access can be performed.

Abstract: An apparatus for determining a type of chord has a means for providing a reference vector for the type of chord, a means for providing a reference vector from a test signal, and a means for comparing the reference vector with the test signal vector. The means for providing a reference vector is configured to provide, for the type of chord, a reference vector from a plurality of different reference vectors. In addition, the means for providing a test signal vector from the test signal is configured to provide the test signal vector having a plurality of test signal vector elements.

Abstract: An encoded rhythmic pattern has several groups of velocity values, wherein the velocity values are sorted, such that the groups are included in sequence in an encoded rhythmic pattern. Now, the velocity values concentrated at the beginning of the encoded rhythmic pattern have a higher importance for characterizing the rhythmic gist of a piece of music than velocity values included in additional groups of velocity values. By using such an encoded rhythmic pattern, an efficient database access can be performed.

Abstract: In order to implement the melody extraction or the automatic clearly more stable or to improve the transcription result, respectively, at the resulting segments or trajectories, respectively, of a melody line gained from a spectrogram of the audio signal a harmony mapping is performed such that a follower segment directly neighboring a reference segment in time direction is virtually shifted in the frequency direction by stages of octave, fifth and/or third in order to examine whether among the resulting lines of the octave, fifth and/or third there is one that fulfills a predetermined condition, like e.g. that the time/spectral representation along this line comprises a minimum which is larger by a certain factor than a minimum that it comprises along the reference segment line, and, if such a line exists, selects the same and actually performs the shifting of the follower segment. This way, errors in melody line determination may be corrected again.

Abstract: An encoded rhythmic pattern has several groups of velocity values, wherein the velocity values are sorted, such that the groups are included in sequence in an encoded rhythmic pattern. Now, the velocity values concentrated at the beginning of the encoded rhythmic pattern have a higher importance for characterizing the rhythmic gist of a piece of music than velocity values included in additional groups of velocity values. By using such an encoded rhythmic pattern, an efficient database access can be performed.

Abstract: For grouping temporal segments of an audio piece, which is structured into main parts repeatedly occurring in the audio piece, into various segment classes, at first a similarity representation for the segments is provided, wherein the similarity representation for each segment comprises an associated plurality of similarity values, wherein the similarity values indicate how similar the segment is to every other segment of the audio piece. Hereupon, using the similarity values associated with the segment, a similarity threshold value for a segment is calculated in order to then associate a segment with a segment class when the similarity value of the segment meets a predetermined relation with reference to the similarity threshold value. With this, clustering is achieved, which also works efficiently and correctly where there are segments with strongly different or almost equal combined similarity values.

Abstract: The finding of the present invention is that the melody extraction or automatic transcription may be implemented clearly more stable and if applicable even less expensive when the assumption is considered sufficiently that the main melody is the portion of a piece of music which man perceives the loudest and the most precise. Regarding this, according to the present invention the time/spectral representation or the spectrogram of an interesting audio signal is scaled using the curves of equal volume reflecting human volume perception in order to determine the melody of the audio signal on the basis of the resulting perception-related time/spectral representation.

Abstract: For the segment class designation the temporal position of segments in two candidate segment classes is used for the stanza/refrain selection by means of a segment class designation means, wherein the highest-order segment class is designated as refrain segment class only when it has a segment following temporally later in the audio piece than the latest segment of the other candidate segment class. With this, segment class labeling with a low error rate is achieved, which can at the same time be implemented with easy effort and is further predestined for automated flow.

Abstract: For changing a segmentation of an audio piece after a segment class assignment, at first a short segment is selected, which has a length shorter than a predetermined minimum length. This short segment is preferably merged with the corresponding successor segment or predecessor segment using information on a segment class membership of the short segment itself, but also the successor segment or the predecessor segment, in order to obtain a changed segmentation of the audio signal. With this, a not over-segmented segment representation of the audio signal is obtained, which further includes all audio information, i.e. is not a representation of the audio piece with holes.

Abstract: An apparatus for analyzing an audio signal with regard to rhythm information of the audio signal by using an autocorrelation function comprises a filter bank for separating the audio signal into at least two sub-band signals. The sub-band signals are examined with regard to periodicities by an autocorrelation function, to obtain rhythm raw-information for the at least two sub-band signals. To reduce or eliminate the ambiguities of the autocorrelation function for periodical signals, the rhythm raw-information is postprocessed to obtain post-processed rhythm raw-information for the sub-band signal. The rhythm information of the audio signal is established based on the postprocessed rhythm raw-information.

Abstract: An apparatus for producing a fingerprint signal from an audio signal includes a means for calculating energy values for frequency bands of segments of the audio signal which are successive in time, so as to obtain, from the audio signal, a sequence of vectors of energy values, a means for scaling the energy values to obtain a sequence of scaled vectors, and a means for temporal filtering of the sequence of scaled vectors to obtain a filtered sequence which represents the fingerprint, or from which the fingerprint may be derived. Thus, a fingerprint is produced which is robust against disturbances due to problems associated with coding or with transmission channels, and which is especially suited for mobile radio applications.

Abstract: A tone smoothing is performed such that to each time section of a melody line segment a number is associated such that for all groups of directly neighboring time sections, to which the same spectral component is associated by the melody line segment, the numbers associated with the directly neighboring time sections are different numbers from one to the number of the directly neighboring time sections, for each spectral component that is associated with one of the time sections of the melody line segment, the numbers of those groups are added up to which time sections of the same the respective spectral component is associated by the melody line segment, a smoothing spectral component is determined as the spectral component for which the greatest summing-up results, and the melody line segment is changed, by associating the determined smoothing spectral component to each time section of the melody line segment.

Abstract: For producing a fingerprint of an audio signal, use is made of information defining a plurality of predetermined fingerprint modi, all of the fingerprint modi relating to the same type of fingerprint, the fingerprint modi, however, providing different fingerprints differing from each other with regard to their data volume, on the one hand, and to their characterizing strength for characterizing the audio signal, on the other hand, the fingerprint modi being predetermined such that a fingerprint in accordance with a fingerprint modus having a first characterizing strength is convertible to a fingerprint in accordance with a fingerprint modus having a second characterizing strength, without using the audio signal. A predetermined fingerprint modus of the plurality of predetermined fingerprint modi is set and subsequently used for computing a fingerprint using the audio signal.

Abstract: An apparatus for analyzing an audio signal with regard to rhythm information of the audio signal by using an autocorrelation function comprises a filter bank for separating the audio signal into at least two sub-band signals. The sub-band signals are examined with regard to periodicities by an autocorrelation function, to obtain rhythm raw-information for the at least two sub-band signals. To reduce or eliminate the ambiguities of the autocorrelation function for periodical signals, the rhythm raw-information is postprocessed to obtain post-processed rhythm raw-information for the sub-band signal. The rhythm information of the audio signal is established based on the postprocessed rhythm raw-information.

Abstract: An apparatus for analyzing an audio signal with regard to rhythm information of the audio signal comprises a filterbank for dividing the audio signal into at least two sub-band signals. Every sub-band signal is examined with regard to a periodicity of the sub-band signal to obtain rhythm raw-information of every sub-band signal. The rhythm raw-information is subjected to a quality evaluation to obtain a significance measure for every sub-band signal. The rhythm information of the audio signal will finally be established by considering the significance measure of the sub-band signal and the rhythm raw-information. This enables a more robust analysis of the audio signal, since sub-band signals, where significant rhythm information are present, are preferred compared to sub-band signals where less significant rhythm information are present, when establishing the rhythm information.