JP2009211802A - Information signal-reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information signal-reproducing device which generates an excellent reproduction sound field, without being influenced by a signal format of voice data to be reproduced or a different recording medium, and constructs an easy-to-use reproduction system. <P>SOLUTION: The medium kind of an optical disk 100 and signal format information on voice data, which are read out from the optical disk 100 and then reproduced, are detected by an RF signal processing circuit 106 and a picture-voice decoding part 107. On the basis of the information thus detected, a system control part 114 and an interface control part 117 control power supply to a speaker amplifier and also control signal processing in a voice signal processing part 109 to properly reproduce a voice according to the voice data to be reproduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information signal reproducing apparatus that reproduces an information signal such as audio data recorded on a recording medium such as various optical disks.

  As a recording medium for providing audio data such as music, an optical disk for music called CD-DA (Compact Disc Digital Audio) is widely used. In this CD-DA, for example, audio data encoded by an LPCM (Linear Pulse Code Modulation) system capable of reproducing the original sound relatively faithfully is recorded and provided to the end user. In recent years, CD-DA in which audio data is recorded in a data storage format called a DTS (Digital Theater System) system has been provided.

  This DTS system is called, for example, a 5.1 channel including five satellite speakers each composed of one front speaker on each side, a center speaker, and one rear speaker on each side, and one subwoofer. This is a method for playing back sound so as to form a realistic sound field using six speakers. Also, home audio systems that are compatible with the DTS system including a CD player and speakers capable of reproducing audio data recorded by the DTS system have been provided. Note that DTS is a registered trademark of Digital Theater Systems, Inc. of the United States.

  Also, an optical disc called a DVD (Digital Video Disc / Digital Versatile Disc) is used as a recording medium for providing digital content such as a movie including audio data such as music and video data for a relatively long time. It is getting to be.

  It is also possible to record and provide music information on this DVD. Like the CD described above, it is possible to reproduce the original sound relatively faithfully, such as music encoded by the LPCM method. A DVD on which audio data is recorded is called DVD-Audio. A DVD in which video data such as a movie is recorded for a relatively long time together with audio data is called a DVD-Video.

  In the case of DVD-Video, video data is recorded after being compressed by, for example, MPEG (Motion Picture Expert Group). Also, audio data such as music, sound effects, and conversations are compressed by the AC-3 (Audio Code number 3) method for the purpose of effective use of the storage area or the formation of a realistic reproduction sound field. Recording is performed or recording is performed using the DTS method described above.

  However, for example, when a home audio system compatible with the DTS system is used to reproduce 2-channel stereo audio data (2-channel stereo source) encoded by the LPCM system recorded on a CD-DA. May occur.

  For example, it is assumed that the audio data of a 2-channel stereo source is distributed to the above-mentioned five satellite speakers called 5.1 channels and one subwoofer using a home audio system compatible with the DTS system. In this case, the bass sound of the reproduced sound may be overemphasized and become uncomfortable. In such a case, the user (user) adjusts the equalizer of the home audio system, but it takes time and effort to obtain good reproduction sound.

  In addition, using a home audio system compatible with the DTS system, audio data from a 2-channel stereo source is converted into front speakers, one on each of the left and right, among the five satellite speakers called 5.1 channels and one subwoofer. Suppose that only playback is used.

In this case, some noise may be emitted from the center speaker to which no audio data is supplied, one rear speaker on each of the left and right sides, and the subwoofer, and it may be impossible to provide a good reproduction sound field. It is done. In such a case, adjustment such as reducing the volume of the speaker that is not used is necessary, which is troublesome for the user.

  This can also occur in a home AV (audio / visual) system including a DVD player compatible with the DTS system. That is, in the case of a DVD in which audio data is recorded by a method other than the DTS method, a good reproduction sound field may not be formed in a home AV system compatible with the DTS method.

  Both CD and DVD are optical discs, and the playback mechanism and playback signal transmission path of the player can be used in common. Therefore, it is possible to form a so-called multi-convertible player that can reproduce information signals recorded on a CD and can reproduce information signals recorded on a DVD.

  However, production intentions and the like differ between music information recorded on a CD-DA and audio data recorded on a DVD-Video. Therefore, when reproducing audio data from a CD-DA or DVD-Video using a multi-convertible player, reproducing audio data recorded on a CD-DA, and audio recorded on a DVD-Video. When playing back data, it is necessary to adjust the volume level.

  That is, music information mainly for listening (for ornamental use) is recorded on the CD-DA, but the average level of the audio data is set relatively low in order to reproduce the music information recorded on the CD-DA satisfactorily. It is often recorded on CD-DA at a higher value. On the other hand, DVD-Video often records content composed of audio data such as movies and video data. The audio data in this case is audio data accompanying the video data and is often created as so-called sound effects, and the average level is often relatively low.

  For this reason, after reproducing and listening to audio data recorded on a CD-DA using a multi-convertible player, the movie audio data and video data recorded on a DVD-Video are reproduced and viewed. In such a case, the volume level is too low and the user has to perform an operation to increase the volume level.

  Conversely, using a multi-convertible player, the audio data and video data of a movie recorded on a DVD-Video are reproduced and viewed, and then the audio data recorded on a CD-DA is reproduced and listened to. In such a case, the volume level is too high, and the user has to perform an operation to lower the volume level.

  Thus, when using a CD player, a DVD player, or a multi-convertible player capable of reproducing information recorded on a CD and information recorded on a DVD, the signal format of audio data, In accordance with the type of recording medium on which the audio data to be reproduced is recorded, the user must adjust the equalizer, the volume and the like so as to form the reproduction sound field most preferred by the user.

  For this reason, if an attempt is always made to form a reproduction sound field according to his / her preference, various adjustments to the reproduction sound are required, which takes a very long time. In addition, the adjustment may not be successful, and as a result, there is a possibility that an optimum environment that suits one's preference cannot be achieved.

  In view of the above, the present invention provides a good reproduction sound field without being affected by differences in signal formats or recording media such as audio data to be reproduced and without bothering the user. An object of the present invention is to provide an information signal reproducing apparatus that can be formed and that can construct an easy-to-use reproduction system.

In order to solve the above-mentioned problem, an information signal reproducing apparatus according to claim 1 is provided.
First information detecting means for detecting first information indicating a type of a recording medium on which the reproduction signal is recorded, from the reproduction signal;
Second information detecting means for detecting second information indicating a signal format of the audio data including the number of reproduction channels of the audio data included in the reproduction signal from the reproduction signal;
Power control means for performing power control of a speaker amplifier according to each of the number of reproduction channels based on the detected first information and second information;
Low-frequency range control means for performing control to emphasize or attenuate the low frequency range of the sound corresponding to the reproduction signal according to the signal format corresponding to the first information;
Is provided.

  According to the information signal reproducing apparatus of the first aspect of the present application, the first information detection means indicates the first type of recording medium (for example, DVD or CD) on which the reproduction signal is recorded. Information is detected. In addition, the second information detection means uses a second information indicating the signal format of the audio data including the number of reproduction channels of the audio data included in the reproduction signal (for example, AC-3 method, DTS method, or other). Information is detected.

  Based on the detected first and second information, the power control means performs power control of the speaker amplifier in accordance with the number of reproduction channels. Further, according to the signal format indicated by the second information corresponding to the first information, the low sound region control means controls to emphasize or attenuate the low sound region of the reproduced sound.

  As a result, it is possible to form a good reproduction sound field without being influenced by differences in signal formats such as audio data to be reproduced, recording media, and the like and without bothering the user. Further, by using the information signal reproducing apparatus, an easy-to-use reproduction system can be constructed.

  According to the present invention, even when the user of the playback device plays back audio data having a different signal format, or when playing back the audio data recorded on a different recording medium, those audio data are reproduced. An optimum reproduction sound field can be automatically formed without being aware of the difference in data characteristics. Therefore, it is possible to reduce the adjustment work for the reproduced sound, and to realize a reproduction apparatus that is very easy to use without bothering.

  In addition, according to the type of audio data to be reproduced, such as music audio or movie audio, it is possible to make optimal sound suitable for the audio data, so that more attractive sound can be generated.

  Also, in a system consisting of five satellite speakers (satellite channels) and one bass dedicated speaker (bass dedicated channel) as in a home theater system, audio data is supplied when reproducing 2-channel stereo audio data. S / N of the reproduction sound field can be greatly improved by muting a channel that is not performed or by stopping the operation of the channel.

  In addition, since the power on / off control of the speaker amplifier and the video output device can be automatically performed, an easy-to-use system can be formed.

1 is a block diagram for explaining a video / audio reproduction device to which an embodiment of an information signal reproduction device according to the present invention is applied. FIG. It is a figure for demonstrating the structural example of the home theater formed using the audio-video reproduction apparatus shown in FIG. It is a figure for demonstrating the output control of the audio | voice data performed in the video / audio reproduction device shown in FIG. 3 is a flowchart for explaining audio data output control performed when it is determined that the loaded recording medium is a DVD in the video / audio reproduction device shown in FIG. 1. It is a figure for demonstrating the signal processing of the audio | voice data performed in the audio | voice signal processing part of the video / audio reproduction device shown in FIG. It is a figure for demonstrating the power supply control and mute control about the speaker amplifier of the audio-video reproduction apparatus shown in FIG. 4 is a flowchart for explaining audio data output control performed when it is determined that the loaded recording medium is a CD in the video / audio reproduction device shown in FIG. 1.

  Hereinafter, an embodiment of an information signal reproducing apparatus according to the present invention will be described with reference to the drawings. In the embodiments described below, the information signal reproducing apparatus according to the present invention is an optical disk reproducing apparatus, which is a music CD (CD-DA), a video DVD (DVD-Video), and an audio DVD. A case where the present invention is applied to a so-called multi-convertible player capable of reproducing with (DVD-Audio) will be described as an example.

[Outline of Video / Audio Playback Device 10 and Home Theater System]
FIG. 1 is a block diagram for explaining an optical disk reproducing apparatus (video / audio reproducing apparatus) 10 to which an information signal reproducing apparatus according to the present invention is applied, and FIG. 2 uses the reproducing apparatus 10 of this embodiment. It is a figure for demonstrating the structural example of the home theater system comprised.

  The playback apparatus 10 of this embodiment can also play back audio data created by the DTS method according to the method. As shown in FIGS. 1 and 2, the playback apparatus 10 of this embodiment includes a left front speaker 20L, a right front speaker 20R, a center speaker 20C, a left rear speaker 20LS, a right rear speaker 20RS, and a subwoofer speaker 20LFE. It is a thing. In other words, the playback apparatus 10 of this embodiment is compatible with a so-called 5.1 channel multi-surround system composed of five satellite speakers and one subwoofer (sound dedicated speaker).

  Then, as shown in FIG. 2, the six speakers are arranged so as to surround the position of the chair indicating the viewing position of the viewer. In the case of FIG. 2, the front speakers 20L and 20R are installed with a video output device 30 such as a television receiver or a monitor receiver interposed therebetween, and the center speaker 20C is installed on the video output device 30 and a subwoofer. The 20LFE is installed on the left side of the video output device 30.

  Also, the left and right rear speakers are slightly behind the chair indicating the viewer's viewing position, and are installed on the left and right wall surfaces so as to sandwich the viewer's position. When each speaker is arranged in this manner and the playback device 10 of this embodiment plays back the movie content recorded on DVD-Video and having the audio data formed in the above-described DTS format, In the same way as when watching a movie, a realistic reproduction sound field (sound listening environment) in which bass is emphasized can be formed.

[Configuration of Video / Audio Playback Device 10]
Next, the reproducing apparatus 10 of this embodiment will be described in detail. In FIG. 1, a disc 100 is an optical disc such as CD-DA, DVD-Video, or DVD-Audio as described above. The CD-DA is recorded with audio data such as music encoded by the LPCM system, audio data such as rakugo, reading, and conversation, or audio data such as music formed by the DTS system.

  DVD-Audio is recorded with audio data of mainly music encoded by various encoding methods. DVD-Video is video data compressed by the MPEG method and accompanying audio data, and is formed by the audio data compressed by the AC-3 method or the MPEG-Audio method or the DTS method. Audio data is recorded.

  As shown in FIG. 1, the reproducing apparatus 10 of this embodiment is configured to receive a reflected light from the optical disk 100 by irradiating the optical disk 100 with a spindle motor 101 that rotates the optical disk 100 and a laser beam. The optical pickup unit 102 for reading out data recorded on the optical disc 100 and the thread motor 103 for moving the optical pickup unit 102 in the radial direction of the optical disc 100 are provided.

  The optical pickup unit 102 includes a laser light source, an objective lens, an optical system such as a quadrant photodetector, and a mechanism such as a biaxial actuator that adjusts the position of the optical pickup unit 2 in the direction orthogonal to the optical disk and the radial direction of the optical disk. Is also provided.

  Then, the optical pickup unit 102 irradiates the optical disk 100 rotated by the spindle motor 101 with a laser beam, and the reflected light from the optical disk 100 that changes according to the pits formed on the optical disk 100 is received by the photodetector. Then, it is converted into an electronic signal, which is supplied to an RFEQ (RF equalizer) amplifier 105.

  The RFEQ amplifier 105 performs equalizing processing on the electric signal supplied thereto, and supplies the electric signal after the equalizing processing to the RF signal processing circuit 106. Based on the electrical signal from the RFEQ amplifier 105, the RF signal processing circuit 106 forms a reproduction RF signal (binary digital signal), a servo error signal such as a focus error signal and a tracking error signal.

  Further, the RF signal processing circuit 106 superimposes information such as duplication control information, medium type, and signal format of the reproduction RF signal, for example, as digital watermark information (electronic watermark) on the video data or audio data. If so, the information is extracted from the formed reproduction RF signal.

  Then, the RF processing circuit 106 supplies the formed reproduction RF signal to the video / audio decoding unit 107 and supplies a servo error signal such as a focus error signal and a tracking error signal to the servo circuit 115. Further, when the RF processing circuit 106 extracts, for example, control information superimposed as digital watermark information on the reproduction RF signal, the RF processing circuit 106 supplies the extracted information to the system control unit 114.

  The servo circuit 115 receives the supply of various servo error signals from the RF signal processing circuit 106 and the control signal from the system control unit 114 to form a focus servo signal and a tracking error signal, which are generated by the optical pickup unit 102. To supply. Thereby, focus servo and tracking servo are applied.

  The servo circuit 115 forms a rotation servo signal based on the servo error signal supplied thereto and the control signal from the system control unit 114, and supplies this to the motor driver 104.

  The motor driver 104 generates a drive signal to be supplied to the spindle motor 101 based on the rotation servo signal for the spindle motor 101 from the servo circuit 115, and supplies this to the spindle motor 101. Further, the motor driver 104 forms a drive signal to be supplied to the thread motor 103 based on the rotation servo signal for the thread motor 103 from the servo circuit 115, and supplies this to the thread motor 103. Thereby, the rotation servos of the spindle motor 101 and the thread motor 103 are applied.

  In this way, the focus servo, tracking servo, and rotation servo are applied so that the optical disc 100 rotates at an appropriate speed, and the laser beam emitted from the optical pickup unit 102 has a proper size. Thus, the target track is accurately scanned, and the data recorded on the optical disc 100 is read correctly.

  On the other hand, the video / audio decoding unit 107 decodes the reproduction RF signal which is a binary digital signal from the RF signal processing circuit 106. As shown in FIG. 1, for example, a D-RAM (Dynamic Random Access Memory) 108 used as a work area during decoding is connected to the video / audio decoding unit 107. Then, as will be described later, the video / audio decoding unit 107 supplies the decoded audio data and the audio signal to the audio signal processing unit 109, and the decoded video data is supplied to the video D / A conversion circuit 113. To supply.

  The video / audio decoding unit 107 also reproduces an RF signal reproduced from a predetermined area of the optical disc 100 in which the signal type of the audio signal such as the medium type, the encoding method of the audio signal, the number of reproduction channels, and the sampling frequency is recorded. Is decoded information (hereinafter referred to as decode information) to the system control unit 114.

  The predetermined area of the optical disk on which the medium type and signal format are recorded is the lead-in area of the optical disk, the TOC (Table Of Contents) or directory area provided at a predetermined position of the optical disk, or before and after the data field. For example, an area of sync words (synchronization information).

  The system control unit 114 is a microcomputer provided with a CPU, ROM, RAM, EEPROM, and the like. The system control unit 114 discriminates the medium type of the optical disc 100 loaded in the reproducing apparatus 10 based on the information extracted by the RF signal processing circuit 106 and the decoding information from the video / audio decoding unit 107. Whether the optical disc 100 is recorded with only audio data or recorded with video data and audio data, and further, the encoding format, the number of reproduction channels, and the sampling frequency of the audio data recorded on the optical disc 100 Is determined.

  The medium type indicates whether the optical disk 100 loaded in the playback apparatus 10 of this embodiment is a CD or a DVD. In this embodiment, the audio data recorded on the optical disc 100 is encoded and recorded by any of the LPCM system, AC-3 system, MPEG audio system, and DTS system. It shows what it is.

  In addition, the number of playback channels indicates whether it is monaural, 2-channel stereo, 5.1-channel multi-surround, or the like. The sampling frequency indicates the sampling frequency in the case of audio data that has been data-compressed by the LPCM method.

  In addition, as described above, the playback apparatus 100 according to this embodiment can determine whether only audio data is recorded or whether video data and audio data are recorded. Yes. In this embodiment, in the case of audio data created by the DTS method, the number of playback channels is 5.1 channel multi-surround.

  If control information or the like is not superimposed on the video data or audio data recorded on the optical disc 100 as digital watermark information, for example, the medium type, the encoding format of the audio data, the number of playback channels, the sampling frequency, etc. This determination is made based only on decoding information from the video / audio decoding unit 107.

  Then, the system control unit 114 forms a control signal for controlling the decoding process of the video data and audio data as the main information according to the analysis result as described above, and supplies this to the video / audio decoding unit 107. . This control signal is information for controlling how video data and audio data or only audio data is decoded.

  The system control unit 114 also notifies the interface control unit 116 of the analysis result as described above. In this embodiment, the interface control unit 116 is a microcomputer including a CPU, ROM, RAM, EEPROM, and the like. The interface control unit 116 controls an operation key unit 117, an operation display unit 118, and a memory slot 119, which will be described later. Further, the interface control unit 116, based on the analysis result from the system control unit 114, an audio signal processing unit, an audio D / A conversion unit 110, an audio volume (indicated as audio VOL in FIG. 1), a speaker. An audio system composed of an amplifier (power amplifier) 112 is controlled.

  That is, in the playback apparatus 10 of this embodiment, the interface control unit 116 controls the audio system, and the system control unit 114 controls each unit other than the audio system, thereby distributing the control load and quickly. And accurate data processing is realized.

  Also, the interface control unit 116 forms display information of information that needs to be notified to the user, such as a medium type, among analysis results from the system control unit 114, and is configured by an LCD (liquid crystal display) or the like. By supplying it to the operation display unit 118, the medium type of the optical disk loaded in the reproducing apparatus 10 of this embodiment is displayed on the operation display unit 118 and notified to the user.

  Then, the video / audio decoding unit 107, in accordance with the control signal from the system control unit 114, as described above, the video data supplied as the reproduction RF signal (binary digital signal) from the RF signal processing circuit 116, Audio data or only audio data is decoded according to the encoding method.

  For example, when the reproduction RF signal is a mixture of video data and audio data and compressed by the same method, the video / audio decoding unit 107 determines that the compressed video data and audio data are The mixed reproduction RF signal is decoded and expanded to separate video data and audio data. The expanded audio data is supplied to the audio signal processing unit 119 and the expanded video data is supplied to the video D / A conversion circuit 113.

  When the reproduction RF signal includes video data and audio data, and each of them is encoded by different encoding methods, the video / audio decoding unit 107 separates the video data and the audio data. The audio data is supplied to the audio signal processing unit 109 in a compressed state, and the video data is decoded and expanded, and the expanded video data is supplied to the video D / A conversion circuit 113.

  When the reproduction RF signal is from CD-DA or DVD-Audio and only audio data not including video data, the video / audio decoding unit 107 performs necessary decoding processing on the audio data. Is supplied to the audio signal processing unit 109.

  The audio signal processing unit 109 decodes the audio data in accordance with the control from the interface control unit 116 when the supplied audio data is data-compressed or the like. The audio data is restored to the original audio data.

  When the audio data has a plurality of reproduction channels, for example, when the audio data is recorded on the optical disc 100 by the DTS method, the audio signal processing unit 109 performs audio data for each reproduction channel. To separate. Also, it can digitally perform filtering processing, delay processing, etc. on the output audio data, and adjust the frequency characteristics and level of the audio data to add the desired effect to the audio data It is.

  In this way, in the case of audio data decoded by the audio signal processing unit 109 and having a plurality of reproduction channels, the audio data for each reproduction channel separated into the respective reproduction channels is converted into the audio D / A circuit 110. To be supplied. The audio D / A circuit 110 converts the audio data supplied thereto from a digital signal to an analog signal, and converts the analog audio signal to the speaker amplifiers 112L, 112C, 112R, 112LS, 112RS, and 112LEF of the corresponding reproduction channel. Supply.

  Each speaker amplifier amplifies the analog audio signal supplied thereto and supplies it to the corresponding speakers 20L, 20C, 20R, 20LS, 20RS, and 20LEF, and drives these speakers. As a result, sound corresponding to the sound data recorded on the optical disc 100 is emitted from each speaker.

  Further, as described above, the video data decoded by the video / audio decoding unit 107 and supplied to the video D / A conversion circuit 113 is supplied from the digital signal to the analog signal here, and the video data of the television receiver or the like is supplied. It is supplied to the output device 30. As a result, a reproduced video corresponding to the video data recorded on the optical disc 100 is displayed on the display screen of the video output device 30.

  Note that the playback apparatus 10 of this embodiment includes not only an optical disc but also a memory slot 119 that is a loading port of an external semiconductor memory 120 called a memory stick or the like. Then, the external semiconductor memory 120 in which video data and audio data are recorded by a digital still camera or a digital video camera and the external semiconductor memory 120 in which audio data is recorded by a recording device are loaded (attached) into a memory slot. The video data and audio data recorded in the external semiconductor memory 120 can be reproduced.

  The interface control unit 116 reads out video data and audio data recorded in the external semiconductor memory 120 loaded in the memory slot 119 through the memory slot 119. In this embodiment, the audio data is supplied from the interface control unit 116 to the audio signal processing unit 109 for reproduction, and the video data is supplied from the interface control unit 116 to the video / audio decoding unit 104, Playback is performed through the video A / D converter 113.

  In addition, the playback device 10 of this embodiment accepts an instruction input from a user (user) of the playback device 10 through the operation key unit 117, performs a process according to the instruction input, or performs an instruction input. Corresponding parameters can be set in the interface control unit 116 or the EEPROM which is a nonvolatile memory of the system control unit 114.

  As described above, the playback apparatus 10 according to this embodiment is capable of audio data and video recorded in various signal formats on different recording media such as CD-DA, DVD-Video, DVD-Audio, or external semiconductor memory. Data can be reproduced.

  The reproduction apparatus 10 is adjusted so that the maximum audio level is equal regardless of the audio data from any recording medium and the audio data of any signal format. As described above, sound data such as music recorded on a CD-DA with a relatively high average sound level and sound recorded with a relatively low average sound level such as movie sound recorded on a DVD-Video. When reproducing data alternately, it may be necessary to manually adjust the volume level each time.

  In other words, due to differences in production intention and creation environment of audio data recorded on the recording medium, the audio data that has been reproduced up to now and audio data recorded on a different recording medium can be reproduced, or different signals When the audio data in the format is reproduced, there are cases where the user has to manually adjust the reproduced audio one by one in order to listen to the reproduced audio satisfactorily.

  Therefore, in the playback apparatus 10 of this embodiment, the user estimates the type of the audio data from the medium type and the signal format of the audio data, and performs output control of the audio data according to the type, thereby enabling the user. Thus, it is possible to listen to the reproduced sound satisfactorily without performing the manual adjustment of the reproduced sound by.

[Inference of audio data type and output control of audio data]
Hereinafter, estimation of the type of audio data and output control of audio data based on the estimation result performed in the playback apparatus 10 of this embodiment will be described. FIG. 3 is a flowchart for explaining the estimation of the type of audio data and the output control of audio data based on the estimation result performed in the playback apparatus of this embodiment.

  In this embodiment, the processing shown in FIG. 3 is performed by the system control unit 114 and the interface control unit 116 when an optical disk or an external semiconductor memory is loaded in the playback apparatus 10 of this embodiment. That is, when the reproducing apparatus 10 is loaded with the optical disk 100, the reproducing apparatus 10 needs to be recorded on the optical disk 100 by rotating the loaded optical disk and irradiating the laser beam from the optical pickup unit 102. Pre-processing to read the correct data.

  That is, when the optical disc 100 is loaded, the playback device 10 has a predetermined position such as a sync word provided before and after the TOC, directory, lead-in area, and data field of the optical disc 100 as described above. The data indicating the medium type and the signal format recorded in is read out.

  As described above, the read data (electrical signal) is supplied to the RF signal processing circuit 106 through the RFEQ amplifier 105, converted into a reproduction RF signal, and supplied to the video / audio decoding unit 107. . At this time, in the RF signal processing circuit 105, information superimposed on the reproduction RF signal is extracted, and the extracted information is supplied to the system control unit 114. Also, the video / audio decoding unit 107 decodes the reproduction RF signal from a predetermined area such as the TOC or the detector of the optical disc, and supplies the decoded information (decoded information) to the system control unit 114.

  Then, as described above, the system control unit 114 supplies the audio data and image data to be reproduced based on the information extracted by the RF signal processing circuit 106 and the decoding information from the video / audio decoding unit 107. It is determined whether the optical disc 100 as the original recording medium is a CD or a DVD (step S101).

  Further, in the playback apparatus 10 of this embodiment, when the external semiconductor memory 120 is loaded in the memory slot 119 and playback of data from the external semiconductor memory 120 is instructed through the key operation unit 117, the interface control unit 116. However, it is determined that the recording medium from which the audio data or image data to be reproduced is the external semiconductor memory 120, and notifies the system control unit 114 of this (step S101).

  Then, the system control unit 114 determines whether or not the recording medium that is the supply source of the audio data and image data to be reproduced is a DVD based on the determination result of step S101 (step S102). If it is determined in step S102 that the recording medium is a DVD, the system control unit 114 executes an audio data output control routine for the DVD (step S103), and the process shown in FIG. Exit.

  If it is determined in step S102 that the recording medium is not a DVD, the system control unit 114 determines whether the recording medium is a CD (step S104). If it is determined in step S104 that the recording medium is a CD, the system control unit 114 executes an audio data output control routine for a CD (step S105), and the process shown in FIG. Exit.

  If it is determined in step S104 that the recording medium is not a CD, the system control unit 114 executes a control routine in other cases (step S106), and ends the process shown in FIG. That is, in this embodiment, in step S106, an audio data output control routine in the case of the external semiconductor memory is executed.

[Output control processing for DVD]
FIG. 4 is a flowchart for explaining the process executed in step S103 of the flowchart shown in FIG. That is, when the system control unit 114 determines that the recording medium on which the audio data to be reproduced is recorded is a DVD, the system control unit 114 executes the processing shown in FIG.

  First, as described above, the system control unit 114 sets the signal format of the audio data to be reproduced based on the information from the RF signal processing circuit 106 and the decode information from the video / audio decoding unit 107. It discriminate | determines (step S201). In the process of step S201, the encoding method of the audio data to be reproduced is determined.

  Then, the system control unit 114 determines whether the encoding format of the audio data to be reproduced is the AC-3 format or the DTS format based on the determination process in step S201 (step S202). If it is determined in step S202 that the encoding format of the audio data to be reproduced is the AC-3 system or the DTS system, it is estimated that the audio data to be reproduced is movie audio. (Step S203).

  That is, among the digital contents provided by the DVD, when the audio data encoding method is the AC-3 method or the DTS method, the digital content is overwhelmingly often a movie digital content. . Based on this empirical fact, when the recording medium is a DVD and the encoding method of audio data recorded on the DVD is the AC-3 method or the DTS method, the reproduction of this embodiment is performed. The apparatus 10 estimates that the audio data recorded on the DVD is movie audio.

  Then, the system control unit 114 determines the number of reproduction channels of audio data to be reproduced based on the information from the RF signal processing circuit 106 and the decoding information from the video / audio decoding unit 107 (step S204). .

  Thereafter, speaker amplifier control corresponding to each speaker corresponding to the number of playback channels (steps) is performed under the control of the interface control unit 116 that receives supply of instruction information according to the determination result of the medium type and signal format from the system control unit 114. S205), low-frequency range emphasis processing (step S206) by the audio signal processing circuit 109, and volume level increase processing (step S207) by the audio volume 111 are performed.

[Details of speaker amplifier control]
Below, each process of step S205 to step S207 is demonstrated. First, speaker amplifier control corresponding to the reproduction channel performed in step S205 will be described. FIG. 5 is a diagram for explaining the speaker amplifier unit 112 of the reproducing apparatus 10 according to this embodiment. As shown in FIG. 5, speaker amplifiers 112L, 112C, 112R, 112LS, 112RS, and 112LEF are provided for each speaker.

  Further, as shown in FIG. 5, power switches S1L, S1C, S1R, S1LS, S1RS, and S1LFE for controlling power supply are provided corresponding to each speaker amplifier, and the audio signal is muted. Mute switches S2L, S2C, S2R, S2LS, S2RS, and S2LFE are provided for performing.

  When the number of playback channels is two-channel stereo, only the power switches S1L and S1R are turned on and the other power switches are turned off under the control of the interface control unit 116. In this case, each mute switch may remain in an off state (non-muted state). Alternatively, only the mute switches S2L and S2R are turned off (not muted), and the other mute switches are turned on (muted). In this case, each power switch may remain on.

  Of course, the power switch of the speaker amplifier to be operated is turned on, the mute switch of the speaker amplifier to be operated is turned off, the power switch of the speaker amplifier that is not operated is turned off, and the speaker amplifier that is not operated is turned on. Both the corresponding power switch and mute switch may be controlled such that the mute switch is turned on.

  When the number of playback channels is 5.1 multi-surround or the audio data signal format is DTS, each power switch shown in FIG. 5 is turned on and each mute switch is turned off. Put it in a state. Thus, according to the number of playback channels, control is performed so that only the speaker amplifier of the speaker corresponding to the playback channel to be used is operated, or the audio signal is output only from the speaker amplifier of the speaker corresponding to the playback channel to be used. By doing so, even if the audio data is two-channel stereo, a good reproduction sound field (reproduction environment) free from noise is realized.

[Details of bass enhancement processing]
Next, the low frequency range emphasis process realized by controlling the audio signal processing unit 109 by the interface control unit 116 in step S206 will be described. FIG. 6 is a diagram for explaining low-frequency range emphasis processing of an audio signal performed by the audio signal processing unit 109 when audio data to be reproduced is 5.1 channel multi-surround.

  In other words, when the audio data to be reproduced is 5.1 channel multi-surround, the interface control unit 116 controls the audio signal processing unit 109, for example, as shown in FIG. , 20C, 20R, 20LS, and 20RS corresponding to the reproduction channels L, C, R, LS, and RS, high pass filters (indicated as HPF in FIG. 6) 91, 92, 93, 94, and 95 are provided. In addition, an adder circuit 96 that adds the audio data of the reproduction channels L, C, R, LS, and RS, and a low-pass filter that receives the output audio data from the adder circuit 96 (denoted as LPF in FIG. 6). 97 and a gain adjustment circuit 98 are provided.

  The HPFs 91, 92, 93, 94, and 95 form audio data to be supplied to the corresponding satellite speakers (speakers other than the subwoofer) by attenuating the bass component of the audio data supplied thereto. Further, the high frequency component is attenuated by supplying the audio data formed by the addition processing by the addition circuit 96 to the LPF 97. By supplying the audio data in which the high frequency component is attenuated to the gain adjustment circuit 98, the signal level of the audio data in which the high frequency component is attenuated is increased and supplied to the subwoofer 20LFE that emphasizes the low frequency range. Audio data to be formed.

  As described above, the function of the audio signal processing unit 109 controlled by the interface control unit 116 enables formation of audio data that reproduces reproduced audio with a sense of presence that emphasizes the low frequency range. When the number of playback channels is two-channel stereo, for example, the low frequency range can be emphasized by attenuating the high frequency component of the audio data supplied to the left and right front speakers with a low-pass filter. In other words, the process of step S206 is to increase the gain of the low frequency range component and emphasize the low frequency.

[Details of audio level up]
Next, a description will be given of an audio level increase realized by controlling the audio volume 111 by the interface control unit 116 in step S207. As described above, since the average sound level of the movie sound is kept relatively low compared to the music sound, in step S207, the sound volume 111 is set so as to increase the signal level of the sound data. Adjustments are made.

  As a result, the signal level of the audio data of the movie to be reproduced is raised to a predetermined level so that the signal levels of the various audio data reproduced by the reproducing apparatus 10 are always substantially constant. Note that the adjustment of the signal level of the audio data can also be performed as digital signal processing in the audio signal processing unit 109 described above. However, by using the audio volume 111, so-called bit dropping of audio data can be prevented, and deterioration of reproduced audio can be prevented.

  As described above, when it is estimated that the audio data to be reproduced is movie sound, the speaker amplifier unit 112 and the sound are reproduced so that the movie sound is best reproduced without bothering the user. The signal processing unit 109 and the audio volume 111 are adjusted. Therefore, when reproducing sound data of movie sound, the reproduction apparatus 10 can be automatically adjusted to a state in which low sound is emphasized and movie sound with a sense of reality can be reproduced.

  On the other hand, when it is determined in step S202 of the flowchart shown in FIG. 4 that the encoding method of the audio data to be reproduced is not the AC-3 or DTS method, the system of the reproducing apparatus 10 according to this embodiment. The control unit 114 estimates that the audio data used for reproduction is music audio (step S208).

  Then, the system control unit 114 determines the number of audio data reproduction channels in the same manner as in step S204 described above (step S209). Similarly to the processing in step S205 described above, the interface control unit 116 causes the power switch S1L, S1C, S1R, S1LS, S1RS, S1LFE and the mute switch S2L, S2C, S2R, S2LS, S2RS, By controlling one or both of the S2LFEs, the speaker amplifier is controlled in accordance with the number of playback channels (step S210).

  Next, under the control of the interface control unit 116, the audio signal processing unit 109 is adjusted so that the low frequency range of the music audio is not emphasized (step S211) unlike the case of movie audio playback. As described above with reference to FIG. 6, the adjustment process performed in step S211 is performed so as not to perform the process of emphasizing the bass, or, on the contrary to the process described above with reference to FIG. This is a process of adjusting the function of the audio signal processing unit 109 so as to attenuate and enhance the high frequency component.

  After the process of step S211, as described above, in the case of music sound, since the average signal level is created relatively high, the sound volume 111 is set so as to reduce the signal level of the sound signal. Adjust (step S212).

  As described above, when it is estimated that the audio data to be reproduced is music audio, the speaker amplifier unit 112, audio is selected so that the music audio is best reproduced without bothering the user. The signal processing unit 109 and the audio volume 111 are adjusted. Therefore, when reproducing audio data of music audio, the playback apparatus 10 can be automatically adjusted to a state where the bass sound is not overemphasized and the music audio can be reproduced at an appropriate volume level.

  Therefore, when the recording medium on which the audio data to be reproduced is recorded is a DVD, the user's hand is bothered regardless of whether the audio data recorded on the DVD is movie audio or music audio. It is possible to automatically adjust the playback device 10 so that the audio data can be played back satisfactorily.

[About output control processing for CD]
FIG. 7 is a flowchart for explaining the process executed in step S105 of the flowchart shown in FIG. That is, when the system control unit 114 determines that the recording medium on which the audio data to be reproduced is recorded is a CD, the system control unit 114 executes the processing shown in FIG.

  First, as described above, the system control unit 114 sets the signal format of the audio data to be reproduced based on the information from the RF signal processing circuit 106 and the decode information from the video / audio decoding unit 107. It discriminate | determines (step S301). In the process of step S301, the encoding method and sampling frequency of the audio data to be reproduced are discriminated.

  Then, the system control unit 114 determines whether or not the encoding format of the audio data to be reproduced is the DTS system based on the determination process in step S301 (step S302). If it is determined in step S302 that the encoding format of the audio data to be reproduced is DTS, the system control unit 114 estimates that the audio data to be reproduced is music audio. (Step S303).

  That is, in the digital content provided by the CD, when the encoding method of the audio data is the DTS method, the digital content is hardly a so-called spoken voice such as conversation or rakugo. It is often music audio produced by recording live concerts.

  Based on this empirical fact, when the recording medium is a CD and the encoding method of the audio data recorded on the CD is the DTS method, the reproducing apparatus 10 of this embodiment It is estimated that the audio data recorded on the CD is music audio.

  When the audio data encoding method is the DTS method, in this embodiment, since all six speakers are used, the interface control unit that receives instruction information from the system control unit 114 is used. As shown in FIG. 5, the power supply 116 supplies power by turning on the power switches of the speaker amplifiers 112L, 112C, 112R, 112LS, 112RS, and 112LFE provided for the speakers. Further, each mute switch is turned off so as not to mute the sound (step S304).

  Then, under the control of the interface control unit 116, the audio signal processing unit 109 is adjusted so that the low frequency range is not overemphasized as in movie audio playback (step S305). Thereafter, the interface control unit 116 adjusts the signal level of the music sound that has been created with a relatively high average sound level, and controls the sound volume 111 so that the signal level of the sound data becomes a predetermined level. Adjustment is made (step S306). Then, the process shown in FIG. 7 ends.

  As described above, when it is estimated that the audio data to be reproduced is DTS music audio, the speaker is adapted to reproduce the DTS music audio best without any trouble of the user. The amplifier unit 112, the audio signal processing unit 109, and the audio volume 111 are adjusted. Therefore, when reproducing audio data of DTS music audio recorded on a CD, the playback device 10 is automatically set in a state in which the bass is not overemphasized and music audio can be reproduced at an appropriate volume level. Can be adjusted.

  If it is determined in step S302 that the encoding method of the audio data to be reproduced is not the DTS method, the system control unit 114 encodes the audio data to be reproduced by the LPCM method. Based on the determination result of step S301, it is determined whether or not the sampling frequency at the time of encoding is equal to or higher than a predetermined value (step S307).

  In the determination process in step S307, in order to obtain a reproduced sound that is as close to the original sound as possible, music information that has been LPCM-encoded at a relatively high sampling frequency or deterioration of the reproduced sound even at a relatively low sampling frequency. This is a process for discriminating whether the voice is a conversation such as a conversation with few.

  If it is determined in step S307 that the sampling frequency is equal to or higher than the predetermined value, the system control unit 114 estimates that the audio data to be reproduced is music audio that is required to be reproduced faithfully to the original sound. (Step S308).

  Then, the system control unit 114 determines the number of playback channels of the audio data to be played based on the determination result of step S301 (step S309), and similarly to the processing of steps S205 and 210 of FIG. Depending on the number of playback channels, the power switch and mute switch can be switched such that only the speaker amplifier corresponding to the speaker to be used is activated or the audio signal from the speaker amplifier corresponding to the speaker that is not used is muted. This is performed (step S310).

  Then, similarly to the processing in steps S305 and S306 described above, the audio signal processing unit 109 is adjusted by the control of the interface control unit 116 so that the bass range is not emphasized too much (step S311). Further, the interface control unit 116 adjusts the signal level of the music sound that is created with a relatively high average sound level, and adjusts the sound volume 111 so that the signal level of the sound data becomes a predetermined level. (Step S312). Then, the process shown in FIG. 7 ends.

  Thus, even if it is estimated that the audio data to be reproduced is music audio other than the DTS system, the music audio is best reproduced without bothering the user. The speaker amplifier unit 112, the audio signal processing unit 109, and the audio volume 111 are adjusted. That is, the playback device 10 can be automatically adjusted so that the bass sound is not overemphasized and the music sound can be played back at an appropriate volume level.

  In the determination process of step S307, when it is determined that the sampling frequency is lower than the predetermined value, the system control unit 114 causes the audio data to be reproduced to be less deteriorated in reproduced audio even if the sampling frequency is relatively low. It is estimated that the voice is spoken (step S313).

  In this case, the voice signal processing unit is configured to increase the signal level of the voice band in the case of conversation under the control of the interface control unit 116 in response to the guess that the voice is a speech from the system control unit 114. 109 is adjusted (step S314).

  As described above, even when it is estimated that the audio data to be reproduced is the speech sound, the speaker amplifier unit 112 is configured to reproduce the speech sound best without bothering the user. The audio signal processing unit 109 and the audio volume 111 can be adjusted.

  Therefore, when the recording medium on which the audio data to be reproduced is recorded is a CD, the user's hand is used regardless of whether the audio data recorded on the CD is music audio or speech audio. Thus, the playback apparatus 10 can be automatically adjusted so that the audio data can be played back without any trouble.

[Output control processing for external semiconductor memory]
If it is determined in the flowchart shown in FIG. 3 that the recording medium on which the audio data to be reproduced is recorded is neither a DVD nor a CD, the system control unit 114 of the reproducing apparatus 10 according to this embodiment. Determines that the recording medium on which the audio data to be reproduced is recorded is an external semiconductor memory loaded in the memory slot 119.

  In the playback apparatus 10 of this embodiment, it is assumed that most of the audio data recorded in the external semiconductor memory is speech voice such as conversation, and in step S106 shown in FIG. As in step S314 shown in FIG. 5, adjustment processing for satisfactorily reproducing the conversational voice is performed.

  When the user gives an instruction to reproduce audio data or video data from the optical disk 100 or the external semiconductor memory 120 loaded in the reproduction apparatus 10, as described above, the adjustment to the audio signal processing unit 109 and the adjustment to the audio volume 111 are performed. Then, the speaker amplifier 112 is adjusted, and the reproduction process is performed in a state most suitable for the audio data to be reproduced.

  As a result, even when audio data having a different recording medium or signal format is reproduced, reproduction processing corresponding to the audio data to be reproduced can be performed at any time. Therefore, the user must manually adjust the reproduced audio. Therefore, it is possible to listen to a good reproduction sound at any time.

  Further, in a system comprising five satellite speakers (satellite channels) and one bass dedicated speaker (bass dedicated channel), as in a home theater system formed using the playback apparatus 10 of this embodiment, two-channel stereo When the audio data is reproduced, the S / N of the reproduction sound field can be improved by muting a channel to which no audio data is supplied or stopping the operation of the channel. This usually improves the S / N of the rear speaker channel, and the noise level of the speaker closer to the listener can be reduced. Therefore, the effect of reducing noise in actual use is great.

  As described above, in the reproduction apparatus 10 of this embodiment, the RF signal processing unit 106, the video / audio decoding unit 117, and the system control unit 114 cooperate to record the optical disk loaded in the reproduction apparatus 10. The medium type and the signal format of the audio data are detected.

  It is also possible to reproduce data from an external semiconductor memory. In this case, the system control unit detects the audio data recording medium or external semiconductor memory to be reproduced by the function of the interface control unit. 114 is notified.

  Then, the system control unit 114 estimates the type of audio data to be reproduced based on the detected medium type or the signal format of the audio data, and based on the estimation result, the interface control unit 116 By controlling the audio signal processing unit 109, the audio volume 111, and the speaker amplifier 112, output control suitable for audio data to be reproduced is performed.

  As described above, the RF signal processing unit 106, the video / audio decoding unit 117, the system control unit 114, and the interface control unit 116 have functions as medium type detection means and signal format detection means. Further, the system control unit 114 has a function as an estimation unit that estimates the type of audio data to be reproduced. In addition, the system control unit 114 and the interface control unit 116 have a function as output control means for performing output control according to audio data to be reproduced.

  Accordingly, the audio data signal output method is controlled according to the type of audio data without installing a large-scale name circuit in the reproduction apparatus 10, thereby optimizing the audio data signal processing method and optimizing the reproduction sound field. Can be realized.

  Note that the attenuation of the high-frequency component and low-frequency component of the audio data performed in the audio signal processing unit 109 depends on the preference of the user of the playback apparatus 10 and the type of audio data. It is also possible to set in advance how much high frequency range or low frequency range component is attenuated.

  Similarly, with regard to the adjustment of the level of the audio data performed in the audio volume 111, how much the level is to be increased for which type of audio data depending on the preference of the user of the playback apparatus 10 and the type of the audio data. Alternatively, it can be set in advance whether to lower.

  Such an adjustment parameter is received by the playback apparatus 10 through the key operation unit 117 and is stored and held in, for example, the EEPROM of the interface control unit 116. As described with reference to FIGS. 3, 4, and 7, when the adjustment is actually performed, the adjustment can be performed according to the parameters stored and held in the EEPROM.

  As described above, the playback apparatus 10 includes a so-called custom mode for performing output control of audio data in accordance with a user instruction and the type of audio data. Even if the user of the playback device 10 of this embodiment does not use the custom mode, the playback device 10 of this embodiment uses the parameters set in advance at the time of manufacture or the like. Audio data output control according to the type of data can be performed.

[Power control of external devices]
In addition, as described above, the playback apparatus 10 of this embodiment is based on information recorded on an optical disc or an external semiconductor memory, and the data recorded on the playback device 10 is only audio data, or video data and audio. It is possible to determine whether the data is recorded.

  Therefore, it is determined whether or not the content including the video data is to be played back, and when the video data is played back and the video output device 30 is not turned on, the playback device 10 sends the video output device. A control signal is transmitted to 30, and the power is turned on. Further, when the video data is not reproduced and the power of the video output device 30 is already turned on, a control signal is transmitted from the playback device 10 to the video output device 30 to turn off the power. To control.

  Such control is performed by connecting the playback apparatus 10 and the video output apparatus 30 using a digital interface of the IEEE 1394 standard. Then, it is only necessary to transmit not only video data but also control information for controlling on / off of the power source from the playback device 10 to the video output device 30 through this digital interface.

  Therefore, the playback apparatus 10 and the video output apparatus 30 are provided with a digital interface, and a control signal for controlling power on / off formed by, for example, the interface control unit 116 of the playback apparatus 10 is transmitted. For this reason, instead of providing a video D / A conversion circuit on the playback device 10 side, a video D / A conversion circuit is provided on the video output device 30 side, and the power supply is switched according to a control signal from the playback device 10. A control unit for controlling on / off is provided.

  In this case, whether the video output device 30 is turned on or not is checked through the digital interface between the playback device 10 and the video output device 30. You can do it. In addition, the playback apparatus 10 manages whether or not the video output apparatus 30 is powered on by its own memory, and controls the power on / off of the video output apparatus according to the information in the memory. You can also.

  As described above, the type of the audio signal to be reproduced can be determined based on the information recorded in the recording medium, and the optimum reproduction sound field can be automatically formed, and the speaker amplifier and the video output device can be formed. It is also possible to perform power on / off control. Further, since output control (signal processing method) of audio data is optimized based on information obtained from the recording medium and power supply control is performed, it is not necessary to provide a special circuit in the playback apparatus 10.

  In the above-described embodiment, when it is determined that the recording medium is a DVD, the audio data to be reproduced is determined to be movie audio or music audio. However, the present invention is not limited to this. Absent. When it is determined that the recording medium shown in FIG. 7 is a CD when a relatively large number of DVD-Audios on which only speech data such as rakugo and lectures are recorded are provided. Similarly to the above process, it is possible to add a process when it is determined that the voice is spoken.

  In the above-described embodiment, the playback apparatus 10 has been described as being capable of playing back three types of optical disks: CD-DA, DVD-Video, and DVD-Audio. However, it is not limited to this. Some recording media called CDs are provided with video data such as Video-CD and CD-G, and new music CDs such as SA-CD (Super Audio CD) are also provided. It is becoming. As an optical disk, there is a large optical disk called LD (laser disk).

  As described above, even when a playback apparatus that enables playback of not only CD-DA, DVD-Video, and DVD-Audio but also other optical disks is configured, the type of each recording medium and its recording medium The type of audio data to be reproduced can be specified based on information such as the audio data and the signal format of the video data, and output control corresponding to the audio data can be performed.

  In addition, when the optical disc playback device is equipped with a digital television broadcast such as sanitary broadcast or a digital audio broadcast reception function, it is optimal based on the difference in the digital signal supply path and the signal format of the received data. It is possible to perform an appropriate signal processing to form an optimal reproduction sound field.

  That is, CD-DA, SA-CD, etc. can be played back as audio media providing audio data, and DVD-Video, Video-CD, CD-G, etc. as media providing audio data and video data. The present invention can also be applied to a reproducing apparatus capable of reproducing various types of optical discs.

  In the above-described embodiment, the case where the present invention is applied to a so-called multi-convertible player capable of reproducing a CD or a DVD has been described as an example. However, the present invention is not limited to this. The present invention can be applied to a reproducing apparatus and a recording / reproducing apparatus for a single recording medium such as a CD player and a DVD player. That is, in the case of a playback device or recording / playback device for a single recording medium, output control of audio data is performed according to the type of audio data to be played back, optimal signal processing is performed, and optimal playback is performed. A sound field can be formed.

  Further, in the above-described embodiment, the description has been given by taking as an example the case of estimating music sound, movie sound, and speech sound, but the present invention is not limited to this. For example, on the basis of information recorded on the recording medium, for example, it is possible to determine whether music sound is pop music or classical music, and perform output control in accordance with it.

  Also, output control of audio data can be performed in accordance with the provision status of digital content provided by a recording medium in the country where the playback device is used. In other words, various parameters for controlling the output of audio data according to the estimation result of the type of audio data are prepared in the playback device, and the parameters to be used are changed according to the country where the playback device is used. You can also

  DESCRIPTION OF SYMBOLS 100 ... Optical disk, 101 ... Spindle motor, 102 ... Optical pick-up part, 103 ... Thread motor, 104 ... Motor driver, 105 ... RFEQ amplifier, 106 ... RF signal processing circuit, 107 ... Video / audio decoding part, 108 ... D-RAM 109: Audio signal processing unit, 110 ... Audio D / A conversion circuit, 111 ... Audio volume, 112 ... Speaker amplifier, 113 ... Video D / A conversion circuit, 114 ... System control unit, 115 ... Servo circuit, 116 ... Interface control part, 117 ... Operation key part, 118 ... Operation display part, 119 ... Memory slot, 120 ... External semiconductor memory, 20 ... Speaker, 30 ... Video output device

Claims (6)

First information detecting means for detecting first information indicating a type of a recording medium on which the reproduction signal is recorded, from the reproduction signal;
Second information detecting means for detecting second information indicating a signal format of the audio data including the number of reproduction channels of the audio data included in the reproduction signal from the reproduction signal;
Power control means for performing power control of a speaker amplifier according to each of the number of reproduction channels based on the detected first information and second information;
Low-frequency range control means for performing control to emphasize or attenuate the low frequency range of the sound corresponding to the reproduction signal according to the signal format corresponding to the first information;
An information signal reproducing apparatus comprising: The information signal reproducing apparatus according to claim 1,
An information signal reproducing apparatus further comprising volume control means for performing control to increase or decrease the volume level of the sound corresponding to the reproduction signal in accordance with the signal format corresponding to the first information. The information signal reproducing apparatus according to claim 1 or 2,
When the signal format is movie sound, the low sound range control means performs control for emphasizing the low sound range of the sound corresponding to the reproduction signal. The information signal reproducing apparatus according to claim 2 or 3,
When the signal format is movie sound, the volume control means is an information signal reproducing apparatus that performs control to increase the volume level of the sound. The information signal reproducing apparatus according to claim 1 or 2,
When the signal format is music sound, the low sound range control means performs control to attenuate the low sound range of the sound corresponding to the reproduction signal. An information signal reproducing apparatus according to claim 4 or 5,
The volume control means is an information signal reproducing apparatus that controls to lower the volume level of the sound.

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