JP5362064B2 - Playback apparatus and playback method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control sound output from a headphone to have frequency characteristics desired by a user. <P>SOLUTION: A reproduction device comprises generation means, correction means, and audio signal output means. On the basis of first data indicating frequency characteristics of sound output from a headphone and second data indicating target frequency characteristics, the generation means generates correction data for correcting the frequency characteristics. The correction means corrects audio data on the basis of the correction data. The audio signal output means outputs audio signals based on the corrected audio data to the headphone. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  Embodiments described herein relate generally to a playback apparatus and a playback method for correcting sound output from headphones.

  When playing music In an environment where the sound cannot be output from a speaker such as outdoors, the user listens to music using headphones such as earphones and stereophones.

  The frequency characteristics of the sound output from the headphones vary depending on the product, and the sound output from the headphones may not have the frequency characteristics desired by the user.

Japanese Patent Publication No. 4-10799

  There is a demand for the sound output from the headphones to have frequency characteristics desired by the user.

  An object of the present invention is to provide a playback apparatus and a playback method capable of making sound output from headphones have frequency characteristics desired by a user.

According to the embodiment, the playback device includes first generation means, correction means, audio signal output means, measurement signal output means, sound data acquisition means, and second generation means. The first generation means generates correction data for correcting the frequency characteristic based on the first data indicating the frequency characteristic of the sound output from the headphones and the second data indicating the target frequency characteristic. . The correcting means corrects the audio data based on the correction data. The audio signal output means outputs an audio signal based on the corrected audio data to the headphones. The measurement signal output means outputs a measurement signal to the audio signal output means. The sound data acquisition means has a first port through which the sound output from the headphones is input based on the measurement signal, and a second port from which the input sound is output from the other end. the have a tube having substantially the same volume as the volume of the ear canal, and acquires the data of the sound corresponding to the sound input to the microphone via an adapter having a sound absorbing material in said tube. The second generation means generates the first data based on the acquired sound data.

1 is a perspective view showing an example of the appearance of a playback apparatus according to a first embodiment. 1 is a block diagram illustrating an example of a system configuration of a playback apparatus according to a first embodiment. 1 is a block diagram showing an example of a configuration for measuring frequency characteristics of an earphone of a media player according to a first embodiment. The figure which shows an example of a structure of the adapter of 1st Embodiment. The figure which shows an example of a structure of the adapter of 1st Embodiment. The figure which shows an example of a structure of the adapter of 1st Embodiment. The figure which shows the frequency characteristic of the sound output from the earphone and acquired with the microphone via the adapter. The block diagram which shows an example of a structure of the correction function of a media player. The figure which shows an example of the frequency characteristic which target characteristic data shows. The figure which shows an example of the frequency characteristic which the designed correction filter shows. The figure which shows the frequency characteristic of the sound output from the earphone. The flowchart which shows an example of the procedure which measures the frequency characteristic of the sound output from the earphone, and correct | amends the sound output from an earphone based on the measured frequency characteristic. The block diagram which shows an example of a structure of the reproducing | regenerating apparatus of 2nd Embodiment. The figure which shows an example of a structure of the adapter of 3rd Embodiment. The block diagram which shows an example of the structure for measuring the frequency characteristic of the earphone of the media player of 3rd Embodiment. The figure which shows the example which acquires directly the audio | voice output from an earphone with a microphone. The figure which shows the example which ensured the space equivalent to the adapter of 1st Embodiment in a display unit. The figure which shows the example which ensured the space equivalent to the adapter of 1st Embodiment in a display unit. The block diagram which shows an example of a structure of the correction function of the media player of 5th Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
(First embodiment)
First, the configuration of the playback apparatus according to the first embodiment will be described with reference to FIGS. 1 and 2. The playback device of this embodiment is realized by, for example, a notebook portable personal computer 10.

  FIG. 1 is a perspective view of the computer 10 with the display unit opened. The computer 10 includes a computer main body 11 and a display unit 12. A display panel 17 having a liquid crystal panel is incorporated in the display unit 12. A microphone is provided in the display unit 12. The display unit 12 is provided with a microphone hole 19 so that the microphone can efficiently collect sound.

  The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position where the upper surface of the computer main body 11 is exposed and a closed position covering the upper surface of the computer main body 11. The computer main body 11 has a thin box-shaped housing. On the top surface thereof, there are a keyboard 13, a power button 14 for powering on / off the computer 10, a touch pad 16, and speakers 18A and 18B. Has been placed.

  Next, the system configuration of the computer 10 will be described with reference to FIG.

  As shown in FIG. 2, the computer 10 includes a CPU 101, a north bridge 102, a main memory 103, a south bridge 104, a graphics processing unit (GPU) 105, a video memory (VRAM) 105A, a sound controller 106, a BIOS- A ROM 109, a LAN controller 110, a hard disk drive (HDD) 111, a DVD drive 112, an embedded controller / keyboard controller IC (EC / KBC) 116, and the like are provided.

  The CPU 101 is a processor that controls the operation of the computer 10 and executes various application programs such as an operating system (OS) 121 and a media player 122 that are loaded from the hard disk drive (HDD) 111 to the main memory 103. The media player 122 is application software for reproducing moving image (video) and audio files. The CPU 101 also executes a BIOS (Basic Input Output System) stored in the BIOS-ROM 109. The BIOS is a program for hardware control.

  The north bridge 102 is a bridge device that connects the local bus of the CPU 101 and the south bridge 104. The north bridge 102 also includes a memory controller that controls access to the main memory 103. The north bridge 102 also has a function of executing communication with the GPU 105 via a PCI EXPRESS standard serial bus or the like.

  The GPU 105 is a display controller that controls a liquid crystal panel 171 used as a display monitor of the computer 10. The GPU 105 uses the VRAM 105A as a work memory. A video signal generated by the GPU 105 is sent to the liquid crystal panel 171.

  The south bridge 104 controls each device on an LPC (Low Pin Count) bus and each device on a PCI (Peripheral Component Interconnect) bus. The south bridge 104 includes an IDE (Integrated Drive Electronics) controller for controlling the hard disk drive (HDD) 111 and the DVD drive 112. Further, the south bridge 104 has a function of executing communication with the sound controller 106. The sound controller 106 is a sound source device. In order to output audio data to be reproduced to the speakers 18A and 18B, a circuit such as a D / A converter that converts a digital signal into an electric signal and an amplifier that amplifies the electric signal is provided. Have. The sound controller 106 has a circuit such as an A / D converter for converting an electric signal input from the microphone 113 into a digital signal.

  The embedded controller / keyboard controller IC (EC / KBC) 116 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 16 are integrated. . The embedded controller / keyboard controller IC (EC / KBC) 116 has a function of powering on / off the computer 10 in accordance with the operation of the power button 14 by the user.

  Next, functions of the media player 122 will be described. The media player 122 has a function of measuring a frequency characteristic of sound output from the earphone. A configuration for measuring the frequency characteristics of the earphone will be described with reference to FIG.

  The media player 122 includes a measurement signal output unit 231, a measurement unit 232, a frequency characteristic data generation unit 233, and the like. The measurement signal output unit 231 generates a measurement signal for measurement, and outputs the generated measurement signal to the D / A converter. The measurement signal is, for example, white noise, pink noise, a unit pulse within a predetermined width, or a time stretched pulse (Time Stretched Pulse: hereinafter referred to as TSP) signal.

  The sound controller 106 includes a D / A converter (digital-analog conversion circuit), an amplifier, an A / D converter (analog-digital conversion circuit), and the like.

  The reference signal is converted into an electric signal by a D / A converter. The converted electric signal is amplified by an amplifier, and the amplified electric signal is input to the earphone 200. Earphone 200 outputs a sound corresponding to the input signal. Sound output from the earphone 200 is input to the microphone 113 via the adapter 210. The microphone 113 converts the input sound into an electric signal and outputs the electric signal to the A / D converter. The A / D converter converts an electrical signal into a digital signal and outputs the digital signal to the measurement unit. The measurement unit 232 measures the sound pressure level of the sound output from the earphone 200 based on the digital signal. The measurement unit 232 outputs the measured sound pressure level to the frequency characteristic data generation unit 233. The frequency characteristic data generation unit 233 generates frequency characteristic data 234 based on the sound pressure level.

  The adapter 210 is used to simulate the sound transmitted to the eardrum through the ear canal. The configuration of the adapter 210 will be described with reference to FIG. The adapter 210 includes a tube 301, a sound absorbing material 302, a packing 303, and the like.

  The pipe 301 is, for example, a resin-made cylinder and has a linear shape such as a water pipe or a gas pipe. Tube 301 has a first mouth into which the earpiece of earphone 200 is inserted and a sound output from earphone 200 is input, and a second mouth from which a sound input from the first mouth is output.

  What is important for the adapter 210 is the volume of the tube 301. Experiments have shown that unnatural resonance occurs when the volume between the earphone 200 and the microphone 113 is too small. On the other hand, when the volume is too large, the sound is attenuated while the sound is transmitted from the earphone 200 to the microphone 113, and there is a problem that the SN ratio of the measurement signal is lowered. Experiments have shown that the appropriate volume of the tube 301 is about the same as the volume of the human ear canal.

  Next, the sound absorbing material 302 will be described. When a tube having the same volume as the ear canal is used, resonance due to the length of the tube occurs, which hinders measurement. In order to suppress resonance, a sound absorbing material is inserted into the tube. The sound absorbing material is, for example, felt and is made of a material that has an effect of reducing the way the sound is transmitted, and has the effect of preventing resonance. As shown in FIG. 4, the position where the sound absorbing material 302 is disposed is effective near the center of the tube. This is because the vicinity of the center is the place where the air vibrates most. Further, as shown in FIG. 5, the sound absorbing material 312 may be packed in the entire tube 301. Moreover, as shown in FIG. 6, the structure which affixed the sound-absorbing material 322 inside the pipe | tube 301 may be sufficient. Furthermore, it is also possible to form the pipe and the sound absorbing material with the same material having a sound absorbing property.

  Next, the packing 303 will be described. The packing 303 prevents the gap between the adapter and the device when the adapter 210 is pressed near the microphone 113, and an O-ring shape is effective. Since the purpose of the packing 303 is to close the gap, it can be arranged on the device side, or it can be omitted if a sealed state can be secured without packing, for example, the device itself is a soft material. .

  FIG. 7 shows frequency characteristics of sound output from the earphone 200 and acquired by the microphone 113 via the adapter.

  Next, the function of the media player using the measured frequency characteristic of the earphone 200 will be described. The playback function of the media player has a correction function that causes the sound output from the earphone 200 to have a target frequency characteristic based on the measured frequency characteristic of the earphone 200. Next, the configuration of the correction function of the media player will be described with reference to FIG.

  As shown in FIG. 8, the media player includes a measurement characteristic acquisition unit 401, a target characteristic acquisition unit 402, a correction filter design unit 404, a decoding unit 406, a correction unit 407, and the like.

  The measurement characteristic acquisition unit 401 acquires the frequency characteristic data 234 generated by the frequency characteristic data generation unit 233. The target characteristic acquisition unit 402 acquires target characteristic data indicating the target frequency characteristic of the sound that is output from the earphone 200 and reaches the eardrum (hereinafter referred to as target characteristic) from the target characteristic storage unit 403. The target characteristic storage unit 403 stores, for example, a plurality of target characteristic data. One of the plurality of target characteristic data indicates, for example, an ideal frequency characteristic. Another plurality of target characteristic data corresponds to a plurality of music genres. FIG. 9 shows an example of the frequency characteristic indicated by the target characteristic data. The target characteristic acquisition unit 402 acquires one target characteristic data selected by the user from among a plurality of target characteristic data stored in the target characteristic storage unit 403.

  The correction filter design unit 404 designs a correction filter (correction data) 405 for bringing the sound that is output from the earphone 200 and reaches the eardrum close to the target characteristic, based on the target characteristic data and the frequency characteristic data. The frequency characteristics indicated by the correction filter 405 are shown in FIG. The correction filter 405 has parameters used in, for example, a general parametric equalizer. Parameters used in the parametric equalizer are the center frequency, the width of the band to be adjusted, and the volume.

  The decoding unit 406 generates audio data by decoding data encoded in a compression format such as MP3. The correction unit 407 corrects the audio data based on the correction filter created by the correction filter design unit 404. The corrected audio data is input to the D / A converter. The D / A converter converts the audio data into an electric signal and outputs the converted electric signal to the amplifier. The amplifier amplifies the electric signal and outputs the amplified electric signal to the earphone 200. FIG. 11 shows the frequency characteristics (correction characteristics) of the sound output from the earphone 200. As shown in FIG. 11, it can be seen that the correction characteristics substantially match the target characteristics.

  Next, a procedure for measuring the frequency characteristic of the sound output from the earphone 200 and correcting the sound output from the earphone 200 based on the measured frequency characteristic will be described with reference to the flowchart of FIG.

  The measurement signal output unit 231 outputs a measurement sound from the earphone 200 by outputting a measurement signal to the sound controller 106 (step 501). The sound output from the earphone 200 is acquired by the microphone 113 via the adapter 210 (step 502). The acquired sound is output to the measurement unit 232. The measurement unit 232 measures the frequency characteristic of the sound and outputs the measurement result to the frequency characteristic data generation unit 233. The frequency characteristic data generation unit 233 generates frequency characteristic data (step 503).

  The target characteristic acquisition unit 402 acquires target characteristic data from the target characteristic storage unit 403 (step 504). The correction filter design unit 404 designs the correction filter 405 based on the frequency characteristic data 234 and the target characteristic data (step 505).

  The decoding unit 406 decodes the music data that has been compression-encoded (step 506). The correction unit 407 corrects the music data decoded based on the correction filter 405 (step 507). The correction unit 407 outputs the corrected music data to the sound controller 106. The sound controller 106 converts the music data into a music signal, amplifies the converted music signal, and outputs the amplified music signal to the earphone 200 (step 508).

It is also possible to perform steps 501 to 505, store the parameters of the designed correction filter, read the parameters at the time of music reproduction, and perform processing from step 506. Since the characteristics of the earphone do not fluctuate greatly, once the first half steps are performed once and the parameters of the correction filter are obtained, the subsequent measurement can be saved by using those parameters.

  According to the present embodiment, when listening with the earphone 200, it sounds like a sound close to the ideal earphone 200. For example, when reproducing music, it is possible to enjoy high-quality music. In addition, even with an earphone 200 with low price and poor characteristics, the user can easily correct the characteristics of the earphone 200 by himself.

  Note that the coefficient of the correction filter is designed by comparing the frequency characteristics of the measured earphone with the characteristics of the ideal earphone. This means that a filter that fills the difference between the characteristics of the two earphones is designed. Therefore, when the same variation is added to the two characteristics, the variation does not appear in the difference. In the present embodiment, the sound absorbing material is provided in the adapter, but the sound absorbing material may be omitted. By omitting, resonance due to the length of the tube occurs, but when resonance occurs at the same frequency for two earphones, there is no change in the difference in characteristics necessary for correction. However, in practice, the resonance frequency may slightly deviate due to differences in the shape of the earphone, the position of the sound source unit in the earphone, and the like, and it is conceivable that a slight correction error occurs in the vicinity of the resonance frequency. Therefore, in the characteristics near the resonance frequency, measures such as applying smoothing in the frequency direction stronger than other bands and limiting the maximum correction amount are taken to reduce the disturbance of the characteristics due to resonance frequency deviation. It is effective to take measures to

(Second Embodiment)
In the first embodiment, the frequency characteristic data of the earphone 200 is measured by a computer. This embodiment demonstrates the structure which acquires the frequency characteristic data of the earphone 200 from the server on a network.

  FIG. 13 is a block diagram illustrating a configuration of a media player of the playback apparatus according to the second embodiment. As shown in FIG. 13, the media player 122 includes a measurement characteristic acquisition unit 411, a target characteristic acquisition unit 402, a correction filter design unit 404, a decoding unit 406, a correction unit 407, and the like.

  The measurement characteristic acquisition unit 411 acquires the frequency characteristic data 244 from the server 410 on the network. The frequency characteristic data 244 is data provided from the manufacturer of the earphone 200. The frequency characteristic data 244 is not a direct measurement of the frequency characteristic of the earphone 200. The frequency characteristic data 244 is a frequency characteristic obtained by measuring the same model as the earphone 200. Since the frequency characteristic data 244 is the frequency characteristic of the same model, the same effect as that of the first embodiment can be obtained.

  Since the other configuration of the media player 122 is the same as that of the first embodiment, description thereof is omitted.

(Third embodiment)
In the first embodiment, the frequency characteristic of the sound output from the earphone is measured using a microphone provided in the computer. This embodiment demonstrates the structure which provided the microphone in the adapter.

  FIG. 14 is a diagram illustrating a configuration of an adapter according to the third embodiment. As shown in FIG. 14, the adapter 330 includes a tube 301, a sound absorbing material 302, a microphone 334, and the like. A microphone 334 is attached to the bottom of the tube 301.

  A configuration for measuring the frequency characteristics of the earphone of the media player of the third embodiment will be described with reference to the block diagram shown in FIG. The signal collected by the microphone 334 is sent to a microphone input terminal 341 provided in the computer 10 as an analog signal, for example. The analog signal input to the microphone input terminal 341 is input to the A / D converter 223. The A / D converter 223 converts the input analog signal into digital data, and outputs the digital data to the measurement unit 232.

  By providing the adapter 330 with the microphone 334, measurement independent of the characteristics of the microphone built in the computer 10 is possible. Further, even when the user owns a plurality of devices, the measurement results between the devices can be shared. It can also be used on terminals that are not equipped with a built-in microphone.

  The analog signal can be input from the line input terminal by amplifying the analog signal to a line level through an amplifier, for example. When the microphone 334 is a digital microphone, when the output from the microphone 334 can be extracted as a digital signal, the input to the device is a digital input.

  According to the present embodiment, by incorporating a microphone in the adapter, it is possible to perform measurement independent of the input characteristics of a microphone that differs for each device. Further, the trouble of pressing the adapter against the microphone at the time of measurement becomes unnecessary, and it is not necessary to provide the adapter 330 with packing.

(Fourth embodiment)
In the first embodiment, the output sound of the earphone is acquired by the microphone 113 via the adapter. In the present embodiment, the output sound of the earphone is directly acquired by the microphone 113.

  FIG. 16 shows an example in which the output sound of the earphone is directly acquired by the microphone 113. In general, the microphone 113 is mounted immediately behind a hole in the device. However, when the earphone 200 is directly pressed, a sufficient space cannot be secured and unnecessary resonance may occur. Therefore, a configuration in which a space corresponding to the adapter is secured in the display unit 12 can be considered. FIG. 17 shows an example in which a space corresponding to an adapter is secured in the display unit 12.

  As shown in FIG. 17, a space 601 is provided in the display unit 12. In the space 601, a microphone port 19 for applying an earphone and a microphone 113 for receiving a measurement signal output from the earphone are provided.

  FIG. 18 shows a modification. In general, a microphone is mounted immediately behind a hole that is vacant in a device, but usually no extra space is provided in order to obtain good sound collection characteristics. When the earphone is directly pressed against this, a sufficient space cannot be secured, and the characteristics of the measurement result may be greatly different due to an acoustic load applied to the earphone transducer different from that attached to the ear. Therefore, a configuration in which a space corresponding to the adapter is secured in the device main body can be considered.

  FIG. 18 shows an example in which a microphone is arranged immediately below a sound collecting hole in order to achieve both of the normal sound collecting performance. As shown in FIG. 18, a microphone 113 is provided directly below the microphone port 19. A sound absorbing material 611 is provided in the space on the right side of the earphone 200. When a sound absorbing material 611 is used in a space provided to make an appropriate acoustic load when measuring the characteristics of the earphone, the generation of standing waves can be suppressed and the characteristics of the earphone can be measured even during normal sound collection. In addition, the frequency characteristics are not disturbed. Various shapes are possible for the space, and it may be round or triangular. It is important to secure a volume equivalent to the ear canal. Moreover, resonance can also be suppressed by using a sound absorbing material.

(Fifth embodiment)
In a portable audio player, an arbitrary correction filter cannot be applied. In the present embodiment, an example of outputting data that has been subjected to a correction filter to a portable audio player will be described.

  The configuration of the correction function of the media player (audio data correction apparatus) will be described with reference to FIG. As shown in FIG. 19, the media player 122 includes a measurement characteristic acquisition unit 401, a target characteristic acquisition unit 402, a correction filter design unit 404, a decoding unit 406, a correction unit 407, an encoding unit 708, and the like. The configurations of the measurement characteristic acquisition unit 401, the target characteristic acquisition unit 402, the correction filter design unit 404, the decoding unit 406, and the correction unit 407 are the same as those in the first embodiment.

  The correction unit 407 outputs the data corrected based on the correction filter 405 to the encoding unit 708. The encoding unit 708 encodes the corrected data and outputs correction data 709 that has been compression-encoded.

  By transferring the correction data 709 to the portable audio player, the sound output from the earphone when the correction data 709 is reproduced becomes a corrected sound.

  In the above-described embodiment, the earphone has been described as an example, but a stereophone can be used instead of the earphone.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  231 ... Measurement signal output unit, 232 ... Measurement unit, 233 ... Frequency characteristic data generation unit, 234 ... Frequency characteristic data, 312 ... Sound absorbing material, 401 ... Measurement characteristic acquisition unit, 402 ... Target characteristic acquisition unit, 403 ... Target characteristic storage 404, correction filter design unit, 405 ... correction filter, 406 ... decoding unit, 407 ... correction unit, 410 ... server, 411 ... measurement characteristic acquisition unit.

Claims (10)

First generation means for generating correction data for correcting the frequency characteristics based on the first data indicating the frequency characteristics of the sound output from the headphones and the second data indicating the target frequency characteristics;
Correction means for correcting audio data based on the correction data;
Audio signal output means for outputting an audio signal based on the corrected audio data to the headphones;
Measurement signal output means for outputting a measurement signal to the audio signal output means;
A first mouth to which the sound output from the headphones is input based on the measurement signal, and a second mouth to output the input sound from the other end, and approximately the volume of the human ear canal a sound data acquisition means for acquiring data of a sound corresponding to the sound input to the microphone via an adapter have a tube with the same volume, provided with a sound absorbing material in said tube,
A playback device comprising: second generation means for generating the first data based on the acquired sound data. The reproducing apparatus according to claim 1 , wherein the sound absorbing material is provided at a central portion in the pipe. Reproducing apparatus according to any one of claims 1 or 2, wherein said adapter microphone and are integral.   The playback apparatus according to claim 1, further comprising an acquisition unit configured to acquire the first data from a server computer connected to a network. Storage means for storing a plurality of third data indicating the target frequency characteristics;
The playback apparatus according to claim 1, further comprising selection means for selecting the second data from the plurality of third data. The playback apparatus according to claim 5 , wherein the plurality of third data corresponds to a plurality of music genres.   The reproducing apparatus according to claim 1, wherein the correction unit is a parametric equalizer. Output measurement signal to headphones,
A first port that is output from the headphones based on the measurement signal and receives the sound output from the headphones, and a second port that outputs the input sound from the other end; have a tube having substantially the same volume as the volume of the ear canal, to obtain data of sound corresponding to the sound input to the microphone via an adapter having a sound absorbing material in said tube,
Based on the acquired sound data, generate first data indicating the frequency characteristics of the sound output from the headphones,
Generating correction data for correcting the frequency characteristics based on the first data and second data indicating the target frequency characteristics;
Audio data is corrected based on the correction data,
A reproduction method for outputting an audio signal based on the corrected audio data to the headphones. Obtaining the first data from a server computer connected to a network
The reproduction method according to claim 8. The second data is selected from among a plurality of third data indicating the target frequency characteristics stored in the storage means.
The reproduction method according to claim 8.

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