JP2008244773A - Mobile communication terminal, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective pseudo surround when a mobile communication terminal is connected to an external device. <P>SOLUTION: When the mobile communication terminal 1 and an external device TV is connected through a connection cable CL, the mobile communication terminal 1 makes the external device TV output prescribed test sound. The sound output from the external device TV is collected by a microphone 500 for surround setting of the mobile communication terminal 1 to thereby calculate a distance from the external device TV to the mobile communication terminal 1 and a distance between sound sources on the external device TV. The mobile communication terminal 1 specifies a sound source position on the external device TV to a user of the mobile communication terminal 1 and sets a virtual sound source position corresponding to the sound source position on the basis of the calculated distance. The mobile communication terminal 1 acquires an HRTF (Head Related Transfer Function) corresponding to the set virtual sound source position and outputs pseudo surround by correcting sound output from the external device TV. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile communication terminal and a program, and more particularly to a mobile communication terminal and a program suitable for surround sound reproduction.

  In mobile communication terminals such as mobile phones, various functions are added in addition to the voice call function, which is a basic function, and the number of functions is increasing. In recent years, for example, music playback functions and digital TV broadcast reception functions are generally installed.

  As described above, mobile communication terminals have been developed not only as telephones but also as portable devices that can handle various media and contents including images (video) and audio, and their performance and functions are also dedicated. It is improved as it approaches.

  However, since the mobile communication terminal needs to be small for portability, there is a physical limit in improving the performance of media playback. In other words, since display panels and speakers mounted on mobile communication terminals are inevitably small in size, the performance (such as resolution and volume) provided by the large display panels and speakers provided in stationary television receivers, etc. In addition, sensory performance such as force and presence may not be obtained with a mobile communication terminal.

In view of such a situation, a technique for enabling video and audio data of a mobile phone to be viewed on a television device has been proposed (for example, Patent Document 1).
JP 2005-252784 A

  As described above, while the option of using other devices is expanded to complement the performance, the performance improvement when the mobile communication terminal is used alone is also achieved. For example, by applying pseudo-surround technology to audio reproduction, a device has been devised to increase the sense of reality by performing three-dimensional audio output even from a single mobile communication terminal.

  Here, in order to obtain a sound surround effect, a technique (so-called 5.1ch surround or the like) in which speakers are arranged not only on the front side but also on the rear side of the listener is the original surround technology. As described above, since the mobile communication terminal is required to be downsized, there are restrictions on the number of speakers that can be mounted, and earphones are often used when being carried. Therefore, the surround technology requiring a large number of speakers cannot be applied to the mobile communication terminal.

  On the other hand, the pseudo surround technology realizes a surround effect only with a front speaker or headphones (earphones) by generating a virtual sound source. The generation of the virtual sound source is realized by sound output control by calculation using a head related transfer function (HRTF) indicating a sound transfer characteristic from the sound source to the listener's ear (eardrum). With such a pseudo-surround technology, even a mobile communication terminal with a limited number of speakers and frequent use of earphones can obtain a realistic sound field due to the surround effect.

  Even if the performance is improved when used alone, in some cases, audio may be output from a larger speaker by connecting to a stationary television or the like. Thus, when outputting sound from the speaker of the external device, since the distance from the sound source to the listener changes, a suitable HRTF differs from the case where the mobile communication terminal is used alone. For this reason, when outputting an audio using an external device, there is a disadvantage that the effect of the surround function provided in the mobile communication terminal cannot be obtained.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mobile communication terminal and a program that realize better audio output.

In order to achieve the above object, a mobile communication terminal according to the first aspect of the present invention includes:
In a mobile communication terminal having a pseudo surround function,
Connecting means for connecting the mobile communication terminal and an external device having at least an audio output function, and transmitting an audio signal from the mobile communication terminal to the external device;
Sound source position specifying means for specifying a sound source position of the external device for a user of the mobile communication terminal;
Surround setting means for calculating and setting parameters for the pseudo surround function based on the sound source position specified by the sound source position specifying means;
Correcting an audio signal to be output based on the setting by the surround setting unit, and outputting at least the external device;
It is characterized by providing.

The mobile communication terminal is
It is desirable to further include sound collection means for collecting sound output from the external device, in this case,
The sound source position specifying means preferably specifies the sound source position of the external device relative to the user of the mobile communication terminal based on the sound collected by the sound collecting means.

in this case,
The sound source position specifying unit measures a distance between the mobile communication terminal and the external device and a distance between a plurality of sound sources on the external device based on the sound collected by the sound collecting unit. Preferably, the sound source position is specified based on the measured distance.

In the mobile communication terminal,
It is desirable that the surround setting unit calculates the parameter for correcting the sound from the virtual sound source based on the sound source position specified by the sound source position specifying unit.

In the mobile communication terminal,
The audio output means can output the audio signal only to the external device when the mobile communication terminal and the external device are connected by the connection means.

Or
The audio output unit may output the audio signal according to the setting of the surround setting unit to both the mobile communication terminal and the external device.

in this case,
The audio output means preferably outputs an audio signal corrected by the parameter set by the surround setting means from the mobile communication terminal, and outputs an audio signal not corrected by the parameter from the external device.

The mobile communication terminal is
The external setting device may further include an external parameter storage unit that stores the parameter for the external device set by the surround setting unit in association with information indicating the external device.
Preferably, the surround setting unit acquires and sets a parameter associated with the external device from the external parameter storage unit in response to the designation of the external device.

The mobile communication terminal is
It is desirable to further comprise function storage means for storing a head related transfer function corresponding to a plurality of sound source positions for the user of the mobile communication terminal.
The surround setting means preferably calculates and sets a parameter relating to the pseudo surround function using a head related transfer function corresponding to the sound source position specified by the sound source position specifying means.

In order to achieve the above object, a program according to the second aspect of the present invention is:
In a computer that controls a mobile communication terminal having a pseudo surround function,
A function of transmitting an audio signal to an external device connected to the mobile communication terminal and having at least an audio output function;
A function of identifying a sound source position of the external device with respect to a user of the mobile communication terminal based on a sound output from the external device based on the transmitted sound signal;
A function for calculating and setting a parameter for the pseudo surround function based on the identified sound source position;
A function of correcting an audio signal to be output based on the setting and outputting to at least the external device;
It is characterized by realizing.

  According to the present invention, effective pseudo surround can be realized.

  Embodiments according to the present invention will be described below with reference to the drawings.

(Embodiment 1)
First, a mobile communication terminal to which the present invention is applied will be described. The mobile communication terminal 1 according to the first embodiment of the present invention is a mobile communication terminal such as a mobile phone or a PHS (Personal Handyphone System), for example, and has basic functions for voice communication and data communication by wireless communication with a base station. And In the present embodiment, in addition to such basic functions, it is assumed that a function for reproducing and outputting various media is provided. Here, the media refers to content including at least sound.

  It is assumed that the mobile communication terminal 1 according to the present embodiment is arbitrarily provided with a function for handling such media. Examples of functions for handling media according to the present embodiment include a music file playback function, a video file playback function, a video shooting function, a television broadcast reception function, and the like. It is assumed that the mobile communication terminal 1 can reproduce / output media according to such a function that is optionally provided.

  That is, if it has a music file playback function, it downloads and outputs music data downloaded from a data communication source or a sound source such as a CD. Also, if you have a movie file playback function, movie shooting function, TV broadcast reception function, etc., the video data acquired by downloading via data communication, the video data shot with the movie shooting function, the received TV broadcast Play and output audio and video such as video data recorded by recording.

  And the mobile communication terminal 1 shall be equipped with the pseudo | simulation surround function for performing a three-dimensional audio | voice output in the case of media reproduction | regeneration. In this case, by correcting the output sound using a head related transfer function (HRTF) corresponding to the positional relationship between the speaker (described later in detail) of the mobile communication terminal 1 and the user of the mobile communication terminal 1 Generates a virtual sound source and outputs sound with surround effect.

  The configuration of such mobile communication terminal 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing an external configuration of the mobile communication terminal 1, and FIG. 2 is a block diagram showing an internal configuration of the mobile communication terminal 1.

  As shown in each figure, the mobile communication terminal 1 includes a control unit 110, a wireless communication unit 120, an operation unit 130, a display unit 140, a call voice processing unit 150, a reception speaker 151, a transmission microphone 152, and a storage unit. 160, a media processing unit 200, a media speaker 300, an external device connection unit 400, a surround setting microphone 500, and the like.

  The control unit 110 is a so-called baseband chip that includes, for example, a CPU (Central Processing Unit) and a RAM (Random Access Memory), and controls each unit of the mobile communication terminal 1. In this embodiment, the function for performing each process mentioned later is implement | achieved because the control part 110 runs a program.

  The wireless communication unit 120 includes a transmission / reception device for performing communication operation of the mobile communication terminal 1, and controls the wireless transmission / reception operation by the antenna 121, thereby performing wireless communication operation between the mobile communication terminal 1 and the base station. Communication functions such as voice calls are realized.

  The operation unit 130 includes, for example, a key and a button configured on the outer surface of the mobile communication terminal 1 and a signal generation circuit that generates a signal corresponding to the operation thereof, as shown in FIG. An input signal corresponding to an operation by the user is input to the control unit 110.

  The display unit 140 includes, for example, a liquid crystal display panel, an organic EL display panel, and the like, and displays and outputs a screen related to each function of the mobile communication terminal 1. In the present embodiment, the video reproduced by the media reproduction / output function is displayed and output.

  The call voice processing unit 150 includes, for example, a voice codec and performs a voice input / output operation related to the voice call function of the mobile communication terminal 1. That is, the digital audio signal received by the wireless communication unit 120 is converted into an analog audio signal and output from the receiving speaker 151, and the audio input from the transmitting microphone 152 is converted into a digital audio signal for wireless communication. By providing it to the unit 120, a voice call is realized.

  The storage unit 160 is configured by a storage device such as a flash memory or a hard disk device, for example, and stores data, programs, and the like necessary for the operation of the mobile communication terminal 1. In this embodiment, storage areas such as a program storage unit 161, a media data storage unit 162, and a setting information storage unit 163 are prepared, and predetermined information is stored in each storage area.

  The program storage unit 161 stores programs executed by the control unit 110 and the media processing unit 200. In the present embodiment, a program for realizing the operation of the entire mobile communication terminal 1 (for example, OS (Operating System)) and various application programs, as well as a program for realizing a media playback / output function are stored. The

  The media data storage unit 162 stores media data that is played back by the media playback / output function of the media processing unit 200. That is, audio data such as music data, video data such as recorded data of television broadcasting, and the like are stored.

  The setting information storage unit 163 stores setting information used in the media playback / output function by the media processing unit 200. In this embodiment, a head-related transfer function (HRTF) used for the pseudo surround function, a parameter used for output sound correction for generating a virtual sound source, and the like are stored.

  The media processing unit 200 is, for example, a processor such as a CPU (DSP: Digital Signal Processor), a DAC (Digital-Analog Converter) or an ADC (Analog-Digital Converter). A so-called application processor composed of a circuit group and the like, and mainly performs processing related to the additional function of the mobile communication terminal 1. In the present embodiment, it is assumed that processing relating to the media playback / output function is performed. That is, processing related to reproduction and output of audio data and moving image data is performed.

  The configuration of the media processing unit 200 will be described with reference to FIG. FIG. 3 is a block diagram illustrating a configuration of the media processing unit 200. As illustrated, the media processing unit 200 includes an image processing unit 210, a display control unit 220, an audio processing unit 230, a surround processing unit 240, an input / output control unit 250, and the like.

  The image processing unit 210 performs processing related to playback of an image (video) included in media data to be played back, by a DSP constituting the media processing unit 200 executing a program. Here, the decoding operation of the encoded image data is performed. It is assumed that this operation is performed by a standard moving image format processing process such as MPEG-4.

  The display control unit 220 includes, for example, a display control chip or a DAC based on the MDDI (Mobile Display Digital Interface) standard. The display control chip of the display control unit 220 outputs the video signal decoded by the image processing unit 210 to the display unit 140 to display and output the reproduced media video. For example, when displaying an image on an external device such as a stationary television receiver, the image signal decoded by the image processing unit 210 is converted into an analog signal by the DAC. The analog video signal in this case is provided to the external device connection unit 400.

  The audio processing unit 230 performs processing related to reproduction of audio included in the media data to be reproduced, by the DSP constituting the media processing unit 200 executing the program. Here, the decoding operation of the encoded audio data is performed. This operation is performed by a processing process of a standardized audio format such as AAC (MPEG2 Advanced Audio Codec).

  The surround processing unit 240 performs processing related to the pseudo surround function of the mobile communication terminal 1 by the DSP that configures the media processing unit 200 executing the program. Functions realized by the surround processing unit 240 will be described with reference to FIG. FIG. 4 is a functional block diagram illustrating functions realized by the surround processing unit 240.

  As illustrated, the surround processing unit 240 functions as an execution determining unit 241, an output destination determining unit 242, a sound source position specifying unit 243, an HRTF selecting unit 244, a parameter setting unit 245, an output audio correcting unit 256, and the like.

  The execution determination unit 241 determines whether or not to perform pseudo surround on the sound reproduced by the sound processing unit 230 in accordance with an instruction from the control unit 110 based on an input signal from the operation unit 130. When performing the pseudo surround, the surround processing unit 240 is operated, a virtual sound source is generated from the audio signal output from the audio processing unit 230, and the pseudo surround effect is given.

  The output destination determination unit 242 determines whether the audio output destination for performing the pseudo surround processing is the media speaker 300 (described later in detail) of the mobile communication terminal 1 or an external device connected to the external device connection unit 400 (described later in detail). Determine if it is a device. In the present embodiment, as shown in FIG. 1, a mobile communication terminal 1 and an external device (a stationary television receiver or the like) are connected using a connection cable CL such as an AV cable (stereo audio (L, R) and a video signal). ). A signal corresponding to the insertion / extraction of the connection cable CL is input from the external device connection unit 400 to the surround processing unit 240. Based on this signal, the output destination determination unit 242 sends the connection cable CL to the external device connection unit 400. If it is connected, it is determined that the output destination is an external device, and if it is not connected, it is determined that the output destination is the media speaker 300.

When it is determined that the sound output destination is an external device, the sound source position specifying unit 243 provides a sound source of the external device to the user of the mobile communication terminal 1 in order to obtain a surround effect with the sound output from the external device. Perform the operation to specify the position. In the present embodiment, the sound source position of the external device is specified based on the sound output from the external device. Here, the external device connected to the mobile communication terminal 1 in the present embodiment is a stationary television receiver (hereinafter referred to as “external device TV”), and at least two or more speakers capable of stereo output. (Sound source). In the present embodiment, it is assumed that the external device TV is provided with two speakers (a left speaker SP _L and a right speaker SP _R ).

  The sound source position specifying unit 243 specifies a sound source position of the external device TV by outputting a predetermined test sound to the external device TV via the external device connection unit 400 and collecting the sound with the surround setting microphone 500. (Details will be described later). In this case, the sound source position specifying unit 243, for example, includes a time setting operation using a timer circuit included in a processor included in the control unit 110 and the media processing unit 200, and a surround setting microphone by software processing by executing a program. An operation of analyzing the sound collected at 500 is performed. In this embodiment, it is assumed that the phase of collected sound is analyzed by executing known phase measurement software or the like.

  The HRTF selection unit 244 selects, from the setting information storage unit 163, an HRTF used for calculation for obtaining a pseudo surround effect. Here, when audio is output from the media speaker 300 of the mobile communication terminal 1, an HRTF is selected in accordance with the positional relationship between the media speaker 300 and the user's head that are defined in advance. When outputting sound from the TV, the HRTF corresponding to the sound source position of the external device TV specified by the sound source position specifying unit 243 is selected.

  The parameter setting unit 245 sets parameters for generating a virtual sound source by performing a calculation using the HRTF selected by the HRTF selection unit 244. It is assumed that the calculation here is performed using an algorithm or the like used in a known pseudo-surround technique.

  The functional configuration of the surround processing unit 240 has been described above. In the present embodiment, each function shown in FIG. 4 is realized by the DSP of the surround processing unit 240 executing a program. Each of these functions is, for example, an ASIC (Application Specific Integrated Circuit: ASIC). It may be realized by a hardware configuration such as an application specific integrated circuit). Returning to FIG. 3, the description of the media processing unit 200 will be continued.

  The input / output control unit 250 includes a DAC, an ADC, an amplifier, and the like, and functions as an interface between the media processing unit 200 and input / output devices such as the media speaker 300, the external device connection unit 400, and the surround setting microphone 500. To do. Here, the digital signal output from the media processing unit 200 is converted into an analog signal and output to the media speaker 300 or the external device connection unit 400, and the analog input signal from the surround setting microphone 500 is converted into a digital signal. To the media processing unit 200. Note that the audio amplifier of the input / output control unit 250 is an amplifier capable of outputting at least 2 channels.

  Here, the media speaker 300 is, for example, a dynamic speaker or the like, and includes at least two or more speakers so that stereo output is possible. In the present embodiment, it is assumed that the left media speaker 300L and the right media speaker 300R that output each of the stereo audio signals (L, R) are provided.

  The external device connection unit 400 is an interface for connecting the mobile communication terminal 1 and the external device TV, and includes a connector to which a connection cable CL is connected as shown in FIG. The connection cable CL is, for example, an AV cable that transmits a stereo audio signal (L, R) and a video signal, and is a plug that can be connected to an analog audio input terminal (L, R) or an analog video terminal of the external device TV ( A round plug or the like) on one end side. The terminal on the other end side connected to the mobile communication terminal 1 of the connection cable CL is, for example, a four-pole flat plug. Therefore, the external device connection unit 400 includes a connector corresponding to the plug shape of the connection cable CL, so that the audio signal and the video signal output from the media processing unit 200 can be connected to the connection cable CL connected to the connector. To the external device TV.

  The surround setting microphone 500 is composed of, for example, a microphone (sound collecting device) such as a ceramic microphone. As shown in FIG. 1, at least near the left end and the right end of the mobile communication terminal 1. Two or more microphones (left surround setting microphone 500L and right surround setting microphone 500R) are arranged. In the present embodiment, the sound output from the external device TV is collected and input to the surround processing unit 240, whereby the sound source position using the input sound is specified. For this reason, the left surround setting microphone 500L and the right surround setting microphone 500R are separated from each other at a constant interval so that the phase difference from two or more speakers serving as stereo sound sources in the external device TV can be measured. Arranged on the terminal 1.

  Next, a functional configuration of the control unit 110 that operates in cooperation with the media processing unit 200 will be described. Here, functions realized by the control unit 110 when the media processing unit 200 performs media playback / output operations will be described. In this case, the control unit 110 functions as a configuration as shown in the functional block diagram of FIG. 5 by executing the program stored in the program storage unit 161.

  As illustrated, the control unit 110 functions as a user interface unit 111, a media acquisition unit 112, a media output unit 113, and the like.

  The user interface unit 111 displays, on the display unit 140, a screen for causing the user to perform a selection operation necessary for media playback / output operation in cooperation with the operation unit 130 and the display unit 140. The media processing unit 200 is instructed to perform an operation corresponding to the operation of the operation unit 130 on the screen.

  The media acquisition unit 112 acquires from the media data storage unit 162 the media to be played instructed by the user interface by the user interface unit 111.

  The media output unit 113 outputs the media data acquired by the media acquisition unit 112 to 200 for reproduction / output.

  In the present embodiment, the functional configuration illustrated in FIG. 5 is realized by the control unit 110 executing a program. However, these configurations may be realized by a hardware configuration such as an ASIC, for example. .

  The above is the configuration of the mobile communication terminal 1 according to the present embodiment. The above configuration is a configuration necessary for realizing the present invention, and other configurations necessary for basic functions and additional functions as a mobile communication terminal are provided as necessary. Shall.

  The operation of the mobile communication terminal 1 having the above configuration will be described below. Here, the operation in the case of outputting the sound of the media reproduced by the mobile communication terminal 1 from the external device TV connected via the connection cable CL in pseudo-surround will be described. The external surround processing executed by the mobile communication terminal 1 in this case will be described with reference to the flowchart shown in FIG. This external surround processing is started when the connection cable CL is connected to the external device connection unit 400 of the mobile communication terminal 1.

  That is, the processing is started when a signal indicating that the connection cable CL is connected to the external device connection unit 400 is input from the external device connection unit 400 to the surround processing unit 240. In this case, the output destination determination unit 242 determines that the output destination of the media reproduced by the operation of the media processing unit 200 is the external device TV, and the execution determination unit 241 controls that the connection cable CL is connected. Notification to the unit 110.

  In the control unit 110, in response to the notification from the execution determination unit 241, whether or not the user interface unit 111 gives a pseudo surround effect to the display for allowing the user to specify the medium to be reproduced and the sound of the medium to be reproduced. A screen including a display for causing the user to select (hereinafter referred to as “media playback screen”) is displayed on the display unit 140 (step S101).

  The user operates the operation unit 130 to specify a medium to be played and select whether or not the pseudo surround effect is necessary. In this case, information indicating the selected medium and information indicating whether or not the pseudo surround effect is necessary are input from the operation unit 130 to the control unit 110.

  Based on the input signal from the operation unit 130, the user interface unit 111 notifies the reproduction target medium to the media acquisition unit 112 and also notifies the execution determination unit 241 whether or not the pseudo surround effect is necessary.

  In this case, the media acquisition unit 112 accesses the media data storage unit 162 and acquires designated media data. On the other hand, the execution determination unit 241 determines whether or not to execute the process related to pseudo surround based on the notification from the user interface unit 111 (step S102). Here, when it is instructed by the user operation that pseudo-surrounding is not required (step S102: No), this process ends. In this case, the media data output by the media output unit 113 is decoded by the image processing unit 210 and the audio processing unit 230 and output to the external device TV as it is. That is, the pseudo surround effect is not given to the audio output of the media.

  On the other hand, when it is selected by the user operation to give the pseudo surround effect (step S102: Yes), the execution determination unit 241 notifies the output destination determination unit 242 to that effect. Since the output destination determining unit 242 determines that the output destination is the external device TV at the start of this processing, the output destination determining unit 242 instructs the sound source position specifying unit 243 to start the sound source position specifying operation.

  In response to an instruction from the output destination determination unit 242, the sound source position specifying unit 243 first starts an operation of measuring the distance D1 between the mobile communication terminal 1 and the external device TV. In this case, the output destination determination unit 242 activates the surround setting microphone 500 to enable sound collection (step S103).

Next, the sound source position specifying unit 243 obtains test sound source data stored in advance in the media data storage unit 162 of the storage unit 160, for example, and causes the audio processing unit 230 to reproduce it. Here, stereo audio for test (that is, 2-channel audio) having the same output of stereo L and R is output from the speaker SP _L and the speaker SP _R of the external device TV (step S104).

  In this case, the sound source position specifying unit 243 outputs the audio signal of the test audio reproduced by the audio processing unit 230 and outputs it to the input / output control unit 250. The input / output control unit 250 converts the audio signal into an analog signal, and outputs the analog signal to the external device TV via the connection cable CL connected to the external device connection unit 400.

  At this time, the sound source position specifying unit 243 measures the elapsed time after outputting the test sound, for example, using a timer operation by a timer circuit provided in the processor of the control unit 110 or the media processing unit 200.

  In this case, the test sound output from the external device TV is collected by the media speaker 300 and input to the surround processing unit 240. The sound source position specifying unit 243 ends the timing operation when the collected sound is input to the surround processing unit 240. Here, the measured time is the time until the sound output from the external device TV reaches the mobile communication terminal 1. Therefore, the sound source position specifying unit 243 calculates the distance D1 (see FIG. 7A) from the external device TV to the mobile communication terminal 1 based on this time and the standard sound speed (step S105).

When the distance D1 is calculated, the sound source position specifying unit 243 measures the distance D2 between the two speakers provided in the external device TV. In this case, the sound source position specifying unit 243 outputs the test sound to the external device TV again, but outputs the sound separately from each of the speaker SP _L and the speaker SP _R of the external device TV. That is, the external device TV is caused to output each of the audio signal that is only the stereo L signal and the audio signal that is only the R signal (step S106). In this case, audio having the same frequency and volume is output as L and R respectively.

Thus the sound is output separately from the respective speakers SP _L and the speaker SP _R of the external device TV, picked up by the surround set microphone 500, input to the surround processor 240. In this case, the sound collected by the left surround setting microphone 500L and the sound collected by the right surround setting microphone 500R are input to the surround processing unit 240 as individual audio signals.

  The sound source position specifying unit 243 measures the phase difference between the left and right speakers (sound sources) of the external device TV based on the time difference between the sounds collected by the left and right surround setting microphones 500 (step S107).

Then, based on the measured phase difference, the distance D1 calculated in step S105, and the like, a distance D2 (see FIG. 7B) between the speaker SP _L and the speaker SP _R of the external device TV is calculated (step 7). S108).

  The calculation of the distance D1 and the distance D2 based on the output sound is performed using a known algorithm or method used in a sound field correction function mounted on an existing AV amplifier product or the like. To do.

  The sound source position specifying unit 243 specifies the position of each speaker (sound source) on the external device TV with respect to the user of the mobile communication terminal 1 using the distance D1 and the distance D2 calculated in this way (step S109). . Here, FIG. 7 shows the positional relationship between the mobile communication terminal 1 and its user, and the external device TV connected to the mobile communication terminal 1. In this embodiment, when the mobile communication terminal 1 is connected to the external device TV and used, as shown in FIG. 7A, the user performs media playback while holding the mobile communication terminal 1 by hand. Shall. As shown in FIG. 7B, it is assumed that the mobile communication terminal 1 and the user (not shown) are located in the center front of the external device TV.

  In this case, the surround setting microphone 500 (see FIG. 1) disposed near the end of the casing of the mobile communication terminal 1 and the user's head are close to each other. The distance D1 calculated in S105 is regarded as the distance from the external device TV to the user's head of the mobile communication terminal 1.

Therefore, based on such a distance D1 from the external device TV to the user's head and a distance D2 between the speaker SP _L and the speaker SP _R on the external device TV, the speaker SP _L and the speaker SP. _The position of each _{R with} respect to the user can be calculated. That is, as shown in FIG. 8, the mobile communication terminal 1, the speaker SP _L, and, since it assumed triangles and vertices speaker SP _R, the straight line corresponding to the distance D2 as the base of the triangle, the distance D1 The corresponding straight line can be a perpendicular line from the bottom to the mobile communication terminal 1. In this case, since the distance D1 and the distance D2 are calculated, the distances (D3 _L) from the mobile communication terminal 1 to each of the speaker SP _L and the speaker SP _R can be calculated by performing calculations using various mathematical methods. , D3 _R ) and angles (θ _L , θ _R ) can be calculated.

As described above, since the distance D1 is the distance from the external device TV to the user's head in the present embodiment, the calculated distance D3 and the angle θ are the speaker SP _L for the user of the mobile communication terminal 1. is an element that indicates the position of the speaker SP _R. Therefore, by analyzing by picking up sound is output from the external device TV, it is possible to specify the position of the speaker SP _L and the speaker SP _R of the external device TV to the user of the mobile communication terminal 1.

Here, when the pseudo surround effect is obtained by the output of the external device TV, the speaker SP _L and the speaker SP _R of the external device TV are respectively front speakers of the listener (user of the mobile communication terminal 1). Original surround sound is a three-dimensional sound output to the listener by outputting from a speaker placed behind the listener, etc. In pseudo-surround, such a rear speaker is used. By setting a corresponding virtual sound source and outputting a sound output as a sound transfer characteristic from the virtual sound source from the front speaker, the surround effect is obtained only by the front speaker.

Therefore, in order to obtain the pseudo surround effect, it is necessary to specify the position of such a virtual sound source. Therefore, the sound source position specifying unit 243 determines the position of the virtual sound source (that is, the rear speaker) based on the positions of the speaker SP _L and the speaker SP _R (that is, the front speaker) of the external device TV specified in step S109. Is set (step S110). In the present embodiment, as shown in FIG. 8, for the user of the mobile communication terminal 1, a virtual sound source VSP _L to the position and the symmetrical position of the speaker SP _L and the speaker SP _R is a front-side speaker VSP _{Let R} be.

In this embodiment, since the position of the mobile communication terminal 1 is regarded as the position of the user (head position), the sound source position specifying unit 243, as shown in FIG. based on the own position), the angle theta is assumed virtual sound source VSP _R corresponding to the back right speaker distance D3 _R behind a position at _R, to a position at an angle theta _L becomes the distance D3 _L behind the left rear speaker By assuming the corresponding virtual sound source VSP _L , the position of the virtual sound source for the user of the mobile communication terminal 1 is set.

  When the position of the virtual sound source is specified in this way, the sound source position specifying unit 243 notifies the HRTF selection unit 244 of the position of the virtual sound source. The HRTF selection unit 244 accesses the setting information storage unit 163 in response to the notification from the sound source position specifying unit 243, and selects and acquires the HRTF (head related transfer function) corresponding to the notified position of the virtual sound source ( Step S111).

  Here, it is assumed that the setting information storage unit 163 stores HRTFs corresponding to a plurality of virtual sound source positions assumed when pseudo-surround output is performed using the mobile communication terminal 1. That is, when the mobile communication terminal 1 is used alone, the media speaker 300 serves as a front speaker, so that the position of the media speaker 300 when the user holds the mobile communication terminal 1 is determined. In addition to the HRTF corresponding to the virtual sound source position being stored as a default, there are a plurality of virtual sound source positions corresponding to various virtual sound source positions that can be assumed when audio is output by connecting to a stationary television receiver such as the external device TV. HRTF is stored.

  The HRTF selection unit 244 selects and acquires the HRTF corresponding to the virtual sound source position specified by the sound source position specifying unit 243 from the plurality of HRTFs prepared as described above. When the HRTF is acquired, the HRTF selection unit 244 notifies the parameter setting unit 245 of the acquired HRTF.

  In response to the notification from the HRTF selection unit 244, the parameter setting unit 245 instructs the audio processing unit 230 to provide the decoded audio data, and performs an operation using the HRTF notified from the HRTF selection unit 244. Then, parameters for correction performed when outputting the provided audio data are set (step S112).

In this case, the audio data decoded by the audio processing unit 230 is assumed to be stereo 2ch audio data, and the parameter setting unit 245 assigns the virtual sound source VSP _L to each of such stereo ch (L and R). correction is set such as parameters corresponding to HRTF of VSP _R. Here, the HRTF, because they are showing the audio transfer characteristics from that location to the eardrum of the listener, for example, the audio to be output from the front of the right speaker SP _R, calculated at HRTF behind the right virtual sound source VSP _R by correcting a parameter, sound output from the right front of the speaker SP _R is heard as if it were outputted from the rear of the right speaker to the listener.

  In this case, the 2ch audio data output from the audio processing unit 230 is artificially allocated to, for example, a 4ch signal including the rear 2ch using the existing technology such as Dolby Pro Logic (trademark), and the rear 2ch is assigned to the rear 2ch. Corresponding audio data is corrected with parameters calculated by the corresponding HRTF, so that pseudo surround setting is performed. Such calculation and parameter setting using the HRTF can be realized by using a known algorithm or method used in a normal pseudo-surround technique.

By outputting the audio data corrected with the pseudo surround parameters set in this way to the input / output control unit 250, the audio data is output to the external device TV as a stereo 2ch analog audio signal (step S113). In this case, from the left speaker SP _L of the external device TV, the sound based on the sound signal of the sound output from the front left speaker and the sound signal corrected to the sound output from the left rear speaker (virtual sound source). There is output from the right speaker SP _R, and the audio of an audio signal output from the front right speaker, audio based on the audio signal corrected in the sound output from the right rear speakers (virtual sound sources) is output Therefore, sound having a surround effect is output from the external device TV at the position of the user of the mobile communication terminal 1.

  By repeating such correction and output processing until a predetermined end requirement such as the end of playback data or an end instruction from the user occurs (step S114: No), sound reproduction with a surround effect is performed. When the termination requirement is generated (step S114: Yes), the process is terminated.

  In this way, when audio is output from an external device, a virtual sound source corresponding to the sound source position of the external device can be generated to give a pseudo surround effect. The parameters set in this case can be used again when the same external device is used. Therefore, the parameters set in step S112 may be stored in the setting information storage unit 163 or the like. In this case, for example, when the user interface unit 111 operates when the playback operation ends, a screen asking the user whether to save the set parameter is displayed on the display unit 140 and stored. For example, the user is allowed to input the name of the external device TV. Then, the parameters set in step S112 are associated with the input name information of the external device TV and stored in the setting information storage unit 163.

  Next time when the external surround processing (FIG. 6) as described above is executed by connecting the connection cable CL, a display for allowing the user to select the name of the external device or the like is displayed on the media playback screen displayed in step S101. Append. Here, when the user operates the operation unit 130 and selects a name of a stored external device or the like, an operation related to the specification of the sound source position is read by reading the parameters stored in the setting information storage unit 163 The pseudo surround output can be started without performing the operation.

(Embodiment 2)
In the first embodiment, when media playback is performed by connecting the external device TV to the mobile communication terminal 1, audio is output only from the speaker of the external device TV, but the speaker of the external device TV and the mobile communication terminal 1 A pseudo surround effect may be obtained by outputting sound using both speakers.

  In this case, if the amplifier capability of the input / output control unit 250 of the mobile communication terminal 1 shown in the first embodiment is capable of outputting at least 4 ch, the same configuration as the mobile communication terminal 1 of the first embodiment is realized. can do.

Then, by performing processing similar to the external surround processing of the first embodiment, the position of the virtual sound source corresponding to the sound source position of the external device TV is specified, and the parameter is set with the HRTF corresponding to the virtual sound source. In this case, the parameter setting unit 245 allocates the 2ch audio data from the audio processing unit 230 to 4ch, corrects the audio data corresponding to 2ch corresponding to the rear virtual sound source, and performs the media speaker of the mobile communication terminal 1 It is made to output from 300. On the other hand, so as to output from the speaker SP _L and SP _R of the external device TV without performing the correction on 2ch corresponding to the front sound.

  That is, in the positional relationship as shown in FIG. 7A, the sound from the virtual sound source as shown in FIG. 8 is output from the media speaker 300 of the mobile communication terminal 1. Therefore, the pseudo surround effect using the virtual sound source assumed when sound is output from the external device TV can be obtained by using the speaker of the external device TV and the speaker of the mobile communication terminal 1.

  According to such a configuration, since the pseudo surround effect is obtained using four speakers, the output sound from the external device TV may be only the sound corresponding to the front 2ch, and from the mobile communication terminal 1 The output sound may be only the sound corresponding to the rear 2ch (virtual sound source). As a result, for example, it is possible to more effectively obtain a sound image when sound is simultaneously output from both the front speaker and the rear speaker, so both the front and rear sounds are output by one speaker. It is possible to realize an audio output with a higher surround effect than the case.

  As in the first embodiment, by storing the set parameters and the external device in association with each other in the setting information storage unit 163, when using the same external device TV, the pseudo surround setting can be performed more easily. Can be done.

  As described above, according to each of the above embodiments of the present invention, it is a case where the reproduced sound from the mobile communication terminal 1 having the pseudo surround function is output from the external device TV such as a stationary television receiver. However, it is possible to perform audio output with a surround effect.

  In this case, the sound output from the external device TV is picked up by the mobile communication terminal 1, whereby the sound source position of the external device TV with respect to the user of the mobile communication terminal 1 is specified, and the virtual sound source corresponding thereto Since the pseudo-surround setting is performed by designating the position, the optimum pseudo-surround setting according to the type and size of the external device TV and the position of the mobile communication terminal 1 (user) can be performed.

  Here, if the amplifier mounted on the mobile communication terminal 1 is a standard amplifier that supports up to 2ch output, for example, as shown in the first embodiment, only the connected external device TV has 2ch. By outputting the audio signal, it is possible to obtain a pseudo surround effect suitable for the situation. On the other hand, if the mobile communication terminal 1 is equipped with, for example, a high-performance amplifier that supports 4ch or more output, as shown in the second embodiment, the speaker of the external device TV and the mobile communication terminal 1 It is also possible to perform more effective surround output using both speakers.

  The said embodiment is an example and the application range of this invention is not restricted to this. That is, various applications are possible, and all embodiments are included in the scope of the present invention.

  For example, in each of the above-described embodiments, for the sake of easy understanding, a case where 4ch surround of the front 2ch and the back 2ch is simulated is illustrated, but the assumed number of channels is arbitrary and is not limited to 4ch. . In other words, if an HRTF corresponding to any sound source position is prepared, a virtual sound source at any position can be generated. For example, 5ch surround including a virtual sound source corresponding to the front center speaker is simulated. May be.

  In the above embodiment, the external device TV connected to the mobile communication terminal 1 is a stationary television receiver. However, any device (for example, an audio device) may be used as long as it is a device capable of outputting sound. It can be used as a device TV.

  In the above embodiment, the position of the virtual sound source is specified by collecting the sound output from the external device TV. However, if the virtual sound source suitable for the sound output from the external device TV can be specified, The method is arbitrary. For example, when a stationary television receiver is assumed as the external device TV, if the distance D1 and the distance D2 calculated in the above embodiment are determined to some extent by the size of the television receiver, etc., the size depends on the size of the television receiver. Parameters are prepared in advance and stored in the setting information storage unit 163. In this case, only by specifying the size of the connected external device TV, appropriate parameters are used, and a suitable pseudo-surround effect can be obtained.

  Further, when the sound from the external device TV is collected and surround is set, in the above embodiment, the two surround setting microphones 500 are used so that the phase difference of the 2ch sound output from the external device TV can be detected. However, if the distance D1 is calculated, sound can be collected by one microphone. In this case, for example, the distance D1 can be calculated by collecting sound using the microphone 152 for transmission. In this case, the distance D2 cannot be measured. For example, if an average distance D2 corresponding to the distance D1 or an average distance D2 corresponding to the size of the external device TV is preset, the distance D2 is actually measured. Even if only the distance D1 can be measured, the pseudo surround setting can be performed.

  In the above embodiment, the pseudo surround setting is performed by regarding the distance D1 from the external device TV to the mobile communication terminal 1 as the distance between the user's head of the mobile communication terminal 1 and the external device TV. However, in order to perform more accurate setting, calculation is performed by adding the distance from the mobile communication terminal 1 to the user's head to the distance D1 from the external device TV to the mobile communication terminal 1. May be. In this case, for example, if the mobile communication terminal 1 is held in the form shown in FIG. 7A, the position of the mobile communication terminal 1 (more specifically, the surround setting microphone 500 is arranged). Since the distance from the position around the user's head to the user's head is almost constant, by storing this distance in the setting information storage unit 163 or the like in advance, pseudo-surround setting based on a more accurate distance can be performed. Can be done.

  In addition, for example, when the mobile communication terminal 1 has an imaging function such as a digital camera function, for example, using a ranging operation or image processing when focusing on a sound source (speaker) position of the external device TV, The sound source position may be specified. In other words, as long as the sound source position of the external device TV can be specified, any method can be used without being limited to the acoustic measurement shown in the above embodiment.

  In the case where voice is also output from the speaker of the mobile communication terminal 1 as in the second embodiment, the mobile communication terminal 1 has a display panel side such as an opening / closing mechanism or a cycloid mechanism using a biaxial hinge. In the case where the direction of the housing can be changed, if the speaker is disposed in the display panel side housing, the distance from the speaker to the user changes depending on the orientation of the housing. Therefore, when the present invention is applied to a mobile communication terminal having such a structure, a plurality of HRTFs corresponding to the orientation of the casing are prepared, and the HRTF corresponding to the orientation of the casing detected by the sensor is prepared. It is desirable to operate to select.

  Moreover, by applying the program to an existing mobile communication terminal or the like as well as being provided as a mobile communication terminal having a function for realizing the present invention in advance like the mobile communication terminal 1 described above. A device having the same function as that of the mobile communication terminal 1 described above can be realized.

  In this case, the program for executing each process described above is applied, and a computer (such as a CPU) that controls the device (such as a mobile communication terminal) executes the program, whereby the mobile communication according to the present invention is performed. It can function as a terminal. That is, the computer may be executed by applying a program for realizing each function of the surround processing unit 240 in the above embodiment. Therefore, in the above-described embodiment, the above-described processing is executed by the operation of the media processing unit 200 prepared separately from the control unit 110. However, the logical function of the surround processing unit 240 is realized by the control unit 110. You may comprise.

  The application method of such a program is arbitrary. For example, the program can be applied to an arbitrary device by providing it via a communication medium such as the Internet, and a predetermined recording medium (for example, a memory card, a CD-ROM, a DVD, Etc.) can also be applied by storing and distributing the program.

It is a figure which shows the external appearance structure of the mobile communication terminal concerning embodiment of this invention. It is a block diagram which shows the internal structure of the mobile communication terminal shown in FIG. FIG. 3 is a block diagram illustrating a configuration of a media processing unit illustrated in FIG. 2. It is a functional block diagram which shows the function structure implement | achieved by the surround process part shown in FIG. It is a functional block diagram which shows the function structure implement | achieved by the control part shown in FIG. It is a flowchart for demonstrating the "external surround process" concerning embodiment of this invention. It is a figure for demonstrating the distance calculated by the external surround process shown in FIG. 6, (a) shows the positional relationship and distance D1 with a mobile communication terminal, the user of a mobile communication terminal, and an external device. (B) shows the positional relationship and distance D2 between the mobile communication terminal and the external device. It is a figure for demonstrating the sound source position of the external device specified by the external surround process shown in FIG. 6, and the position of the set virtual sound source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mobile communication terminal, 110 ... Control part, 111 ... User interface part, 112 ... Media acquisition part, 113 ... Media output part, 120 ... Wireless communication part, 121 ... Antenna, 130 ... Operation part, 140 ... Display part, DESCRIPTION OF SYMBOLS 150 ... Voice processing part, 151 ... Reception speaker, 152 ... Transmitting microphone, 160 ... Storage part, 161 ... Program storage part, 162 ... Media data storage part, 163 ... Setting information storage part, 200 ... Media processing part, 210 ... Image processing unit, 220 ... Display control unit, 230 ... Audio processing unit, 240 ... Surround processing unit, 241 ... Execution determination unit, 242 ... Output destination determination unit, 243 ... Sound source position specifying unit, 244 ... HRTF selection unit, 245 ... Parameter setting section, 250 ... Input / output control section, 300 ... Media speaker, 300L ... Left media speaker, 00R ... right medium speaker, 400 ... external device connecting section, 500 ... surround set microphone, 500L ... left surround set microphone, 500R ... right surround set microphone, CL ... connecting cable, TV ... external device, SP _L ... Left speaker, SP _R ... right speaker, VSP _L ... left virtual sound source, VSP _R ... right virtual sound source

Claims (10)

In a mobile communication terminal having a pseudo surround function,
Connecting means for connecting the mobile communication terminal and an external device having at least an audio output function, and transmitting an audio signal from the mobile communication terminal to the external device;
Sound source position specifying means for specifying a sound source position of the external device for a user of the mobile communication terminal;
Surround setting means for calculating and setting parameters for the pseudo surround function based on the sound source position specified by the sound source position specifying means;
Correcting an audio signal to be output based on the setting by the surround setting unit, and outputting at least the external device;
A mobile communication terminal comprising: Sound collection means for collecting sound output from the external device;
The sound source position specifying means specifies a sound source position of the external device with respect to a user of the mobile communication terminal based on the sound collected by the sound collecting means;
The mobile communication terminal according to claim 1. The sound source position specifying unit measures a distance between the mobile communication terminal and the external device and a distance between a plurality of sound sources on the external device based on the sound collected by the sound collecting unit. Identifying the sound source location based on the measured distance;
The mobile communication terminal according to claim 2. The surround setting means calculates the parameter for correcting the sound from the virtual sound source based on the sound source position specified by the sound source position specifying means;
The mobile communication terminal according to any one of claims 1 to 3. The audio output means outputs the audio signal only to the external device when the mobile communication terminal and the external device are connected by the connection means.
The mobile communication terminal according to claim 1, wherein the mobile communication terminal is a mobile communication terminal. The audio output means outputs the audio signal according to the setting of the surround setting means to both the mobile communication terminal and the external device.
The mobile communication terminal according to claim 1, wherein the mobile communication terminal is a mobile communication terminal. The audio output means causes the mobile communication terminal to output an audio signal corrected with the parameters set by the surround setting means, and outputs an audio signal not corrected with the parameters from the external device.
The mobile communication terminal according to claim 6. An external parameter storage means for storing a parameter for the external device set by the surround setting means in association with information indicating the external device;
The surround setting unit acquires and sets a parameter associated with the external device from the external parameter storage unit in response to the designation of the external device.
The mobile communication terminal according to claim 1, wherein the mobile communication terminal is a mobile communication terminal. A function storing means for storing a head related transfer function corresponding to a plurality of sound source positions for the user of the mobile communication terminal;
The surround setting means calculates and sets a parameter related to the pseudo surround function using a head related transfer function corresponding to the sound source position specified by the sound source position specifying means.
The mobile communication terminal according to claim 1, wherein the mobile communication terminal is a mobile communication terminal. In a computer that controls a mobile communication terminal having a pseudo surround function,
A function of transmitting an audio signal to an external device connected to the mobile communication terminal and having at least an audio output function;
A function of identifying a sound source position of the external device with respect to a user of the mobile communication terminal based on a sound output from the external device based on the transmitted sound signal;
A function for calculating and setting a parameter for the pseudo surround function based on the identified sound source position;
A function of correcting an audio signal to be output based on the setting and outputting to at least the external device;
A program characterized by realizing.

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