# US 7,745,714 B2 · Recording or playback apparatus and musical piece detecting apparatus

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- Number: US 7,745,714 B2
- Document ID: US7745714B2
- Status: Granted
- Kind: B2
- Application number: 12/053,647
- Filed: 2008-03-24
- Published: 2008-10-02
- Granted: 2010-06-29
- Earliest claimed: 2007-03-26
- Assignees: Sanyo Electric Co., Ltd.
- Inventors: Satoru Matsumoto; Yuji Yamamoto; Tatsuo Koga
- Web page: https://patentgrep.com/patent/US7745714B2

## CPC

- G10H 1/0008: {Associated control or indicating means}
- G10H 2210/046: for differentiation between music and non-music signals, based on the identification of musical parameters, e.g. based on tempo detection
- G10H 2210/066: for pitch analysis as part of wider processing for musical purposes, e.g. transcription, musical performance evaluation; Pitch recognition, e.g. in polyphonic sounds; Estimation or use of missing fundamental
- G10H 2240/061: MP3, i.e. MPEG-1 or MPEG-2 Audio Layer III, lossy audio compression
- G10H: ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE

## Abstract

Provided is a recording or playback apparatus capable of separating a musical piece from an audio including the musical piece and a speech through a simple arithmetic process. A cut point detector detects, as a cut point, a time point at which an audio signal level or an amount of change in the audio signal level is not lower than a predetermined value. A frequency characteristic amount calculator calculates a characteristic amount in a frequency area of the audio signal only at each cut point and in its proximity. A cut point judging unit judges an attribute of the cut point on a basis of the calculated characteristic amount of the frequency. A music section detector detects a start and end points of each music section on a basis of the attribute and an interval between sampling points.

## Claims

### Claim 1

An apparatus implementing at least recording or playback that detects a music section from an audio signal, comprising:
a cut point detector that detects a time point as a cut point where a level of an audio signal or an amount of change in the audio signal level is equal to or more than a predetermined value;
a frequency characteristic calculator that calculates a characteristic in a frequency domain of the audio signal only at each cut point;
a music section detector that detects a start point and an end point of a music section; and
an attribute determining unit that determines whether the audio signal at each cut point belongs to a music section or to a non-music section on a basis of the characteristic calculated by the frequency characteristic calculator; wherein
the music section detector presumes that the audio signal between non-music section is a music section, when a time interval between two neighboring non-music section is not shorter than a predetermined length of time.