JP2014106406A - Audio file speed control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio file speed control system in which a performance can be played while the speed of a sound source is changed by conducting, and a CD or the like can be used as the sound source.SOLUTION: An audio file speed control system comprises: reproduction means for reproducing an original sound source; trajectory acquisition means for acquiring the trajectory of a conducting action; performance speed storage means for calculating and storing a temporal position of a beat and a performance speed from the trajectory acquired by the trajectory acquisition means; determination means for determining the number of trials of the performance speed storage means; reference speed ratio determination means for determining a speed ratio after a plurality of numbers of trials by the determination means; output means for changing and outputting a reproduction speed by the reference speed ratio determination means; and beat data acquisition means for acquiring beat data derived by a conductor with a keyboard or a foot switch.

Description

        The present invention relates to an application for playing back an audio file such as a CD by changing the speed of the audio file by holding a command stick or conducting a command against an infrared sensor with a bare hand.

      A baton, a strain gauge attached to the baton and detecting the distortion of the bar that occurs when the baton is swung, and the output signal from the strain gauge to process the speed and size of the performance song An automatic performance device comprising a processing unit adapted to change according to the swing of the baton. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 06-301381 (Claims, Claim 1)

    There has been no conventional technique for changing the performance speed of an audio file such as a CD in real time by conducting or the like. The present invention has a bare hand or a command stick as an input means, and can perform by changing the speed of the sound source of the audio file by conducting a command according to a general command method, and a widely used audio file such as a CD. The object is to provide two points that can be used as a sound source.

Reproduction means for encouraging the conductor to conduct a command by playing the original sound source that is the target of changing the playing speed in the audio file speed control system,
Trajectory acquisition means for acquiring the trajectory of the commanding action expressed by the conductor with a sensor,
Performance speed storage means for deriving beat data from the trajectory of the commanding action acquired by the locus acquisition means, calculating the temporal position of the beat and the performance speed, and storing them in a reproduction program;
Determination means for determining the number of trials of the performance speed storage means;
After performing a plurality of trials by the determination means, a plurality of performance speeds are evaluated to determine a reference performance speed as a reference for changing the playback speed, and a ratio to a mechanical playback speed of the audio file; A reference speed ratio determining means for determining a reference speed ratio,
An audio file speed comprising: output means for changing the playback speed of the audio file by the reference speed ratio determining means; and beat data acquisition means for acquiring beat data derived by the conductor using a keyboard or a foot switch. The problem was solved by the control system.

      According to the present invention, it is possible to perform by changing the speed of the sound source of the audio file in real time by conducting a command according to a general command method with a bare hand or a command stick as an input means. It is also possible to use audio files such as CDs that are widely used as sound sources.

The operating principle of the present invention is shown in FIG. The waveform G-1 of the audio sound source in FIG. 1 shows an audio waveform in which the same sound type having the sound source length T1 is recorded twice as an envelope.
This waveform does not have performance information such as beats or performance speed, and is reproduced at a constant reproduction speed.
The reproduced sound waveform G-2 in FIG. 1 shows the waveform of the original sound source and the performance speed changed by command. In the asynchronous mode for acquiring performance information, it is the same as the original sound source, but in the mode synchronized with the input of performance information, the length T1 of the sound source is increased 1.5 times in synchronization with the conductor's hand trajectory G-3. Yes.
The change in the performance speed of the playback sound waveform G-2 is obtained by combining the asynchronous mode in which the playback sound of the audio file does not change with conduct and the synchronous mode in which the playback sound of the audio file changes with conduct.
The audio file does not have performance information such as beat and performance speed necessary for performance. However, the conductor listens to the playback sound of the audio file, and from the melody and rhythm information expressed by the played sound, the performance information such as the beat and performance speed inherent in the playback sound can be obtained. And knowledge of music scores.
Therefore, if a commander recognizes the commanding action using a sensor or the like and analyzes the track of the conductor's command with respect to the playback sound of the audio file, the performance inherent in the audio file is shown in the track G-3 of the conductor's hand. Information can be obtained, and by using this performance information, the performance speed of the audio file can be controlled to the intended speed.

In the asynchronous mode, the temporal position of the beat can be known from the downward peak of the trace G-3 of the conductor's hand played as the sound source. The performance speed can be calculated from the time between these beats. Asynchronous mode continues for about 1 second, and then automatically switches to synchronous mode. In the asynchronous mode, performance information such as beats and performance speed is stored in the playback program, but what is actually played back is the original sound.
In the synchronous mode, the performance information G-4 is output from the conductor to the playback program, and the playback speed changes. According to the analysis of the conductor's hand trajectory G-3, in the performance information output G-4, the intervals 4 and 5 are 1.5 times the interval T0 between the beats 1 and 2. This means that the conductor wants to play the melody of the sound source 1.5 times slower. With this output, the playback program changes the performance speed of the sound source using a technique in which the pitch does not change even if the performance speed changes.

A flowchart of the operation principle of the present invention is shown in FIG. The original sound source is reproduced from the reproduction program by the reproduction means of the means S11 for reproducing the original sound source to prompt a commanding action. Next, means S12 for interpreting the performance information of the original sound source by the conductor is performed. The means S13 is used for the conductor to express the performance information by conducting the sensor, and the sound data of the audio file and the performance information such as beats are related. Interpretation of performance information is based on the conductor's sense of music and knowledge of sheet music, and the representation of performance information is based on general command methods.
The means S15 for conducting the trajectory of the commanding action acquired by the means S14 for obtaining the trajectory of the commanding action by the sensor is analyzed by the image analysis program, and the means S15 for deriving the beat and calculating and storing the speed of the beat is performed. The beat data is calculated by the means of S15 to evaluate the influence of noise and the like, and the temporal position and velocity which are the attributes of the beat are calculated and stored. Thus, beats and beat attributes are stored in the reproduction program.
In order to determine the reference speed ratio, which is the reference playback speed ratio in consideration of fluctuations and habits of the conductor's movement, trials of a plurality of beats are required, and the number of trials is determined by the trial number judgment means S16. Judging. The reference speed ratio is a value obtained by evaluating a speed ratio that is a ratio of a mechanical playback speed of an audio file and a performance speed of music inherent in the audio file.

When the number of trials is less than the set value, the means for storing the beat and the beat speed is performed, and the process returns to S11. When the number of trials is less than the set value, the original sound source is reproduced as it is regardless of the conductor's intention, so that the reproduced sound is asynchronous with respect to the command operation.
When the number of trials reaches the set value, the reference speed ratio determining means S18 determines the basic reference speed ratio for changing the speed by eliminating the influence of the conductor's fluctuations and wrinkles.
The reproduction program realizes the reproduction of the audio file at the performance speed according to the intention of the conductor by means S19 for changing and outputting the reproduction speed of the audio file according to the inputted performance information. When the number of trials reaches a specified value, the playback sound is synchronized with the command action.

The procedure shown in FIG. 2 and described above is straightforward for the conductor and can be used by a general user who has not received any special training. However, since it is assumed that the ratio between the performance speed and the playback speed of the music is constant, it can be applied to simple music, but for music with complex performance speed changes, the data is reset and asynchronous.・ Repeat synchronization. For this reason, the conduct becomes unnatural, and if there are performers who perform at the same time, the conduct may be lost. For this purpose, a rehearsal mode was devised.
The rehearsal mode is a mode in which all tunes are conducted asynchronously as preparation for performance, and complete beat data is stored in the audio file in advance. Since the beat data stored in the audio file is synchronized with the conductor data at the time of performance, the performance speed of a complex music whose ratio between the performance speed and the playback speed is not constant can be changed by a natural command method.
As a simple input method for inputting performance information, there is a foot switch 9 (described in FIG. 3) or a keyboard 10 (described in FIG. 3). When the conductor inputs performance information as preparation for an official performance by the rehearsal mode by means S11 for reproducing the original sound source, the conductor inputs only beat information directly derived from the reproduced sound by the conductor. Since it is good, input by the keyboard 10 (described in FIG. 3) is simple. Further, when the conductor wants to use the reproduced sound as an accompaniment while playing the instrument himself, it can be realized by using the foot switch 9 (shown in FIG. 3).

    FIG. 3 shows an example of an embodiment for carrying out the invention. An infrared sensor 3 is arranged opposite the conductor 1. The computer 2 is installed with an audio file editing program including an image analysis program and a reproduction program, and an operation panel 7 is displayed. The computer 2 and the infrared sensor 3 are connected by a USB cable 6, and the computer 2 and the speaker 4 are connected by an audio cable 5. When the sound source is a CD-ROM, it is inserted into the slot 8 of the computer. If the sound source is stored in the computer, that file is used. When the conductor 1 conducts the infrared sensor 3, the speed of the reproduction sound changes. When the performer holds an instrument and plays with the playback sound of an audio file, the speed of the playback sound is changed by connecting the foot switch 9 to the computer 2 with the USB cable 6 and tapping the foot switch 9 with the foot. It can also be made. Also, the speed of the playback sound can be changed using the keyboard 10.

    FIG. 4 shows image input divisions. General command is performed in the command region 11 above the line that keeps the arm of the commander 1 horizontal. For this reason, the operation area 12 of the reset and operation panel was set in a range not used for command. By using the operation area 12, when performing a performance on the stage, the performance can be performed without placing a computer displaying an operation panel in the vicinity of the conductor. The infrared sensor 3 is installed on a horizontal line that keeps the conductor 1's arm horizontal.

FIG. 5 shows a flowchart of the speed control system. System startup S1 is a means to confirm that the device is connected, the power is turned on, the infrared sensor 3 (shown in FIG. 3) is operating normally, and the confirmation lamp on the operation panel 7 (shown in FIG. 3) is turned on. It is.
The initial condition setting S2 is a means for operating the operation panel 7 (shown in FIG. 3) with a keyboard, a mouse, or the like, and is a setting means for performing an initial setting such as an input method, selection of a song to be played, or a part.
Next, the type of sensor to be used is determined in sensor type determination S3. When the infrared sensor 3 (shown in FIG. 3) is used, the operation coordinate acquisition S4 is executed, and the operation purpose determination S5 is determined based on the acquired coordinate position.
When the purpose of the motion is command, noise removal, peak value detection, and performance information calculation based on the peak are performed by means of motion image analysis S7. Next, by using the method of image analysis evaluation S8, performance information is evaluated in consideration of techniques such as abbreviated command and division command used in general command methods, and the performance information presumed to be intended by the conductor is obtained. create.
The means for outputting the performance speed S9 is means for outputting the performance speed to the reproduction system based on the performance information evaluated by the image analysis evaluation S8. In accordance with this output, the means for editing and reproducing the audio file S10 is executed.
The case where the performer does not use the infrared sensor 3 (shown in FIG. 3) in the sensor type determination S3 is a case where a simple input is made from the foot switch 9 (shown in FIG. 3) or the keyboard 10 (shown in FIG. 3). In this case, the means for outputting the performance speed S9 calculates the performance speed based on the input beat data, and executes the means for editing and reproducing the audio file S10.
If it is determined that the purpose of the operation is other than the command in S5, it is interpreted as the purpose of operating the playback method, and the means of the change of the playback method to change the performance music, etc. Return to acquisition S4.

Principle of operation Flow chart of operating principle An example of the form for carrying out the invention Image input division diagram Flow chart of speed control system

    The present invention makes it possible to participate in music in the role of a conductor who is generally difficult to experience. In addition, it is possible to match the accompaniment to the performance, instead of performing along with the accompaniment. As a result, it is expected that the form of performance for enjoying original music only becomes more general and provides new possibilities for the music industry. Specifically, a new possibility of creating your own song is born in the karaoke market. Minus-one usage may become more widespread. In addition, rehearsals and performances can be performed without using an actual orchestra, and as a result, performance costs associated with the use of the orchestra can be greatly reduced.

G-1 Waveform of audio source G-2 Waveform of playback sound G-3 Trace of conductor's hand G-4 Output of performance information 1-conductor 2-computer 3-infrared sensor 4-speaker 5-audio cable
6-USB cable 7-Operation panel 8-CD-ROM slot 9-Foot switch 10-Keyboard 11-Command area 12-Reset and operation panel operation area S1-System activation S2-Initial condition setting S3-Sensor Type determination S4-Operational coordinate acquisition S5-Operational purpose determination S6-Reproduction method change S7-Image analysis of operation S8-Evaluation of image analysis S9-Output of performance speed S10-Edit and playback of audio file S11-Original sound source S12-Means for the conductor to interpret the performance information of the original sound source
S13-Means for the conductor to express the performance information S14-Means for obtaining the trajectory of the conducting action S15-Means for deriving beats and calculating and storing the beat speed S16-Judgment means for the number of trials
S17-Means for storing beats and beat speeds S18-Means for determining a reference speed ratio S19-Means for changing and outputting the playback speed of an audio file

Claims (2)

Reproduction means for encouraging the conductor to conduct a command by playing the original sound source that is the target of changing the playing speed in the audio file speed control system,
Trajectory acquisition means for acquiring the trajectory of the commanding action expressed by the conductor with a sensor,
Performance speed storage means for deriving beat data from the trajectory of the commanding action acquired by the locus acquisition means, calculating the temporal position of the beat and the performance speed, and storing them in a reproduction program;
Determination means for determining the number of trials of the performance speed storage means;
After performing a plurality of trials by the determination means, a plurality of performance speeds are evaluated to determine a reference performance speed as a reference for changing the playback speed, and a ratio to a mechanical playback speed of the audio file; An audio file speed control system comprising: a reference speed ratio determining means for determining a reference speed ratio, and an output means for changing and outputting an audio file reproduction speed by the reference speed ratio determining means. The audio file speed control system according to claim 1, further comprising beat data acquisition means for acquiring beat data derived by a conductor using a keyboard or a foot switch.

Images