JP2007213661A - Audio reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the operation of selecting an audio stream to be output from a plurality of audio streams. <P>SOLUTION: A disk reproducing device comprises: a system controller for reading the audio streams from a DVD; an audio mixing engine for outputting the voice signal of LPCM obtained by mixing main audio, sub audio and effect audio; a second switching unit for switching to a first output mode for outputting the audio stream of the main audio or a second output mode for outputting the mixed LPCM; an operation part for receiving a switching instruction to perform switching to the first output mode or the second output mode; and a control means (S14 or S24) for controlling to read the audio stream before the reception in accordance with the reception of the switching instruction from the first output mode to the second output mode (YES in S13 or S23). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an audio playback device, and more particularly to an audio playback device that plays back audio recorded in the HD DVD (High Definition-Digital Versatile Disc) video standard.

  Currently, DVD playback devices on the market output one audio stream selected from eight audio streams. For this reason, the audio circuit outputs a single audio stream as a bit stream or outputs a decoded LPCM (Linear Pulse Code Modulation) and an analog signal converted to analog. And an analog output terminal.

  On the other hand, the HD DVD standard has been established, and development of a playback device that plays back video and audio recorded in the HD DVD standard is underway. In the HD DVD standard, three audio objects of main audio, sub audio, and effect audio are recorded on the DVD. The main audio sound object can include eight sound streams, and the sub-audio and effect audio sound objects each include one sound stream. The maximum eight audio streams included in the main audio audio object are synchronized with the audio streams included in the sub audio and effect audio audio objects. When outputting three audio objects recorded on a DVD in accordance with the HD DVD standard, one audio stream selected from a maximum of eight audio streams included in the audio object of the main audio, sub audio, and effect An audio stream included in each audio object is output. For this reason, it is conceivable to provide three digital output terminals and three analog output terminals in order to output three audio streams to the DVD playback apparatus, but this is not practical in terms of manufacturing cost.

  Therefore, a mode for outputting one selected from three audio streams from a single digital output terminal or an analog output terminal and a mode for mixing and outputting three audio streams are provided. Can be considered. However, when the main audio is multi-channel, there is a problem that the sound quality deteriorates when the main audio is mixed with the sub audio and the effect audio and output. For this reason, when the main audio is multi-channel, it is desired to select the main audio from the three audio streams and output the main audio. On the other hand, if the main audio is output and it is found that there is sub audio or effect audio, it may be desirable to mix and output the three audio streams at the expense of the sound quality of that portion. is there.

For this reason, it is necessary to switch from the mode in which main audio is selected and main audio is output to the mode in which three audio streams are mixed and output, but the audio stream to be output is selected from the three audio streams. There is a problem that the operation for switching the mode and the operation for switching the mode become complicated.
Japanese Patent Laying-Open No. 2005-086486

  The present invention has been made to solve the above-described problems, and one of the objects of the present invention is to provide an audio reproducing apparatus that facilitates an operation of selecting an audio stream to be output from a plurality of audio streams. It is to be.

  Another object of the present invention is to provide an audio reproduction apparatus capable of outputting all of a plurality of read audio streams from one output terminal while maintaining the sound quality of the output audio stream. .

  In order to achieve the above-described object, according to one aspect of the present invention, an audio reproduction device reads out a plurality of audio streams synchronized with each other from a recording medium, and mixes the plurality of audio streams and outputs mixing data Switching means for switching to one of a first output mode for outputting a selected stream selected from a plurality of audio streams and a second output mode for outputting mixing data, a first output mode, and a second output mode. A receiving means for receiving a switching instruction to switch to any one of the output modes, and a plurality of audio streams before the received time point are read in response to receiving the switching instruction from the first output mode to the second output mode. And a control means for controlling the reading means.

  According to this aspect, in response to receiving an instruction to switch from the first output mode that outputs a selected stream selected from a plurality of audio streams to the second output mode that outputs mixing data obtained by mixing the plurality of audio streams. A plurality of audio streams before the accepted time point are read out. For this reason, audio streams other than the selected stream can be output from the beginning, not from the middle. In addition, the output data can be switched by a simple operation such as inputting a switching instruction. As a result, it is possible to provide an audio reproducing apparatus that facilitates an operation of selecting an audio stream to be output from a plurality of audio streams.

  Preferably, the reading unit includes a detecting unit that detects a position where an audio stream other than the selected stream is present among the plurality of audio streams, and the control unit is configured to detect a plurality of audio from the position detected by the detecting unit. The reading means is controlled to read the stream.

  Preferably, the control means controls the reading means so as to read a plurality of audio streams a predetermined time before the time when the switching instruction is accepted by the accepting means.

  Preferably, the control unit controls the reading unit to read a plurality of audio streams from the beginning of a chapter including a plurality of audio streams read at the time when the switching instruction is received by the receiving unit.

  Preferably, the control unit controls the switching unit to switch from the second output mode to the first mode in response to the fact that an audio stream other than the selected stream among the plurality of audio streams is not read by the reading unit.

  Preferably, the control means, in the second output mode after accepting the switching instruction from the first output mode to the second output mode, when a plurality of audio streams at the time of the switching instruction are read next, The switching means is controlled to switch to the first output mode.

  According to another aspect of the present invention, an audio reproducing device includes a reading unit that reads a plurality of audio streams synchronized with each other from a recording medium, a mixing unit that mixes a plurality of audio streams and outputs mixing data, and a plurality of audios A switching means for switching between a first output mode for outputting the selected stream selected from the stream and a second output mode for outputting the mixing data; and when the selected stream is read by the reading means, Control means for controlling the switching means to switch to the first output mode and to switch to the second output mode when at least one of the plurality of audio streams other than the selected stream is read by the reading means. And comprising.

  According to this aspect, when the selected stream is read from the recording medium, the selected stream is output. When at least one audio stream other than the selected stream is read from the recording medium, a plurality of selected streams are output. Mixing data obtained by mixing the stream is output. Therefore, when an audio stream other than the selected stream has not been read, the selected stream is output while maintaining the sound quality, and when at least one audio stream other than the selected stream is read, a plurality of audio streams are output. The stream is mixed and output. As a result, it is possible to provide an audio reproducing apparatus that can output all of the read audio streams from one output terminal while maintaining the sound quality of the output audio stream.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a diagram showing an overall configuration of a disk reproducing apparatus according to one embodiment of the present invention. Referring to FIG. 1, a disc playback apparatus 100 is loaded with a DVD 20 on which image data and audio data in which images and audio are compression-encoded and loaded, and reads the image data and audio data from the DVD 20 to reproduce the image and audio. To do.

  The disc playback apparatus 100 includes a system controller 10 that controls the entire disc playback apparatus 100, a LAN (Local Area Network) interface 15 connected to the system controller 10, an operation unit 12, a display unit 13, and a read buffer 26. A playback buffer memory 38, a demultiplexer 31, and an on-screen display (OSD) circuit 37.

  The DVD 20 is rotated by a spindle motor 22. The servo circuit 23 controls the rotation speed of the spindle motor 22 and the focus servo and tracking servo of the pickup 21. When reproducing the title recorded on the DVD 20, the data recorded on the DVD 20 is read by the pickup 21. The pickup 21 receives the light reflected by the DVD 20, converts the received light into an electrical signal by a photoelectric conversion element, and outputs the electrical signal to the demodulation unit 24. Since the electric signal input to the demodulator 24 is a signal modulated into a signal suitable for recording on the DVD 20, the demodulator 24 demodulates it and restores it to its original form. The error correction unit 25 performs error correction using a Reed-Solomon product code (RS-PC) correction method, and stores the error-corrected data in the read buffer 26.

  The system controller 10 includes a navigation information analysis unit 11. The navigation information analysis unit 11 reads data from the read buffer 26 and analyzes navigation information. Further, the system controller 10 stores the video PES (Packetized Elementary Stream) and the audio PES read from the read buffer 26 in the reproduction buffer memory 38.

  The video PES and audio PES stored in the reproduction buffer memory 38 are read by the demultiplexer 31, and the demultiplexer 31 outputs the video PES to the MPEG video decoder 32 and outputs the audio PES to the audio circuit 41. The audio PES includes three types: an audio stream of main audio, an audio stream of sub audio, and an audio stream of effect audio. The audio circuit 41 is controlled by the system controller 10 to process three types of audio streams, and outputs a digital output terminal HDMI (High-Definition Multimedia Interface) 42, S / PDIF (Sony / Philips Digital Interface) 43, and an analog output terminal. Audio data is output from 44. Details of the audio circuit 41 will be described later.

  The MPEG video decoder 32 decodes the input video PES by the MPEG method and outputs the decoded video data to the video encoder 33. The video encoder 33 encodes the video data and outputs it to the adder 35. The video encoder 33 is controlled by the system controller 10 and changes the luminance of the video.

  The OSD circuit 37 outputs bitmap data based on the character information instructed to be output from the system controller 10 to the adder 35. The OSD circuit 37 outputs a message screen for displaying a message indicating that sub audio and effect audio described later are present to the adder 35. The adder 35 superimposes the message screen input from the OSD circuit 37 on the image of the video signal input from the video encoder 33 and outputs it to the video output terminal 36. The video output terminal 36 is connected to, for example, a television receiver, and when a video signal video or a message screen is output from the OSD circuit 37, a video signal video superimposed on the video signal video is output to the TV. Output to John receiver.

  The LAN interface 15 is a communication interface for connecting the disc playback apparatus 100 to the Internet 16. Here, the LAN interface 15 is connected to the Internet 16, and the system controller 10 can communicate with a computer 17 connected to the Internet. The computer 17 stores data that has been compression-encoded according to the MPEG standard, and transmits the stored data in response to a request from the disk playback device 100. For this reason, the disc playback apparatus 100 receives data from the computer 17 and plays back video and audio in the same manner as the data read from the DVD 20 described above.

  The operation unit 12 includes a plurality of button switches provided on the front surface of the disc playback apparatus 100. The operation unit 12 accepts an input of an instruction from a user who operates the disc playback apparatus 100. The operation unit 12 can wirelessly communicate with a remote controller (remote controller) 14 using infrared rays. The remote controller 14 has a button switch for inputting an instruction similar to that of the operation unit 12. Therefore, the user can input an instruction similar to that input to the operation unit 12 using the remote controller 14.

  The display unit 13 is a fluorescent display tube, and displays the operation state of the disc playback apparatus 100, displays a user instruction input to the operation unit 12, and the like. Note that a liquid crystal display device, an organic electroluminescence display, an LED (Light Emitting Diode) panel, or the like may be used instead of or together with the fluorescent display tube.

  FIG. 2 is a block diagram showing a detailed configuration of the audio circuit. Referring to FIG. 2, the audio circuit 41 receives a main audio sound stream, a sub audio sound stream, and an effect audio sound stream. The audio circuit 41 includes a main audio decoder 51 for decoding the main audio sound stream, a sub audio decoder 52 for decoding the sub audio sound stream, and an effect audio decoder for decoding the effect audio sound stream. 53, an audio mixing engine 54, a first switch 55, a second switch 56, and a digital / analog converter (DAC) 57.

  The sub audio decoder 52 outputs to the system controller 10 a signal indicating that the sub audio sound stream exists while the sub audio sound stream is input. The effect audio decoder 53 outputs a signal indicating that the audio stream of the effect audio exists to the system controller 10 while the audio stream of the effect audio is input.

  While at least one of the sub audio sound stream and the effect audio sound stream is input, the system controller 10 notifies the user that either the sub audio sound stream or the effect audio sound stream exists. The system controller 10 detects that a sub audio sound stream is being input while a signal indicating that a sub audio sound stream is present is input from the sub audio decoder 52. Further, the system controller 10 detects that effect audio is being input while a signal indicating that an audio stream of effect audio is present is input from the effect audio decoder 53.

There are the following three methods for notification by the system controller 10. Any one of these three methods may be notified alone, or a combination of two or more may be notified.
(1) The system controller 10 causes the OSD circuit 37 to display a message. The message is, for example, “I have sub audio.”, “I have effect audio.” Or “I have sub audio and effect audio.”
(2) The system controller 10 lights the notification LED provided in the display unit 13.
(3) The system controller 10 controls the video encoder 33 to change the luminance of the video.

  The audio mixing engine 54 receives the main audio decoded from the main audio decoder 51, the sub audio decoded from the sub audio decoder 52, and the effect audio decoded from the effect audio decoder 53. The audio mixing engine 54 is controlled by the system controller 10 to mix main audio, sub audio, and effect audio, and outputs an LPCM audio signal to the input terminal a of the second switch 56 and the DAC 57.

  In the first switch 55, a main audio sound stream (bit stream) is input to the input terminal a, and a sub audio sound stream is input to the input terminal b. The first switch 55 is controlled by the system controller 10 and outputs either the main audio sound stream input to the input terminal a or the sub audio sound stream input to the input terminal b to the second switch 56. To the input terminal b.

  In the second switch 56, an LPCM audio signal obtained by mixing main audio, sub audio, and effect audio is input to the input terminal a, and the output of the first switch 55, that is, the audio of the main audio or sub audio, is input to the input terminal b. One of the streams is input. The second switch 56 is controlled by the system controller 10 and is an LPCM audio signal obtained by mixing main audio, sub audio, and effect audio input to the input terminal a, and main audio or sub audio input to the input terminal b. Are output to the digital output terminals HDMI 42 and S / PDIF 43.

  The system controller 10 switches the first switch 55 and the second switch 56 according to the audio output setting input to the operation unit 12 by the user. The input of the audio output setting to the operation unit 12 includes the input to the remote controller 14. When the audio output setting is set to the main audio output, the system controller 10 switches the first switch 55 to the input terminal a side and switches the second switch 56 to the input terminal b side. When the audio output setting is set to the sub audio output, the system controller 10 switches the first switch 55 to the input terminal b side and switches the second switch 56 to the input terminal b side. If the audio output setting is not set for either the main audio output or the sub audio output, the system controller 10 switches the second switch 56 to the input terminal a side. Here, the audio output setting of the main audio output or the sub audio output is referred to as a first mode, and the audio output setting that is neither the main audio output nor the sub audio output is referred to as a second mode.

  The DAC 57 converts the LPCM audio signal obtained by mixing the main audio, sub audio, and effect audio input from the audio mixing engine 54 into an analog signal, and outputs the analog signal to the analog output terminal 44.

  FIG. 3 is a flowchart illustrating an example of the flow of detection display processing. The detection display process is a process executed by the system controller 10. Referring to FIG. 3, system controller 10 determines whether or not a sub audio stream is input (step S01). If a signal indicating that a sub audio stream is present is input from the sub audio decoder 52, the system controller 10 proceeds to step S03, and if not, proceeds to step S02. In step S02, it is determined whether an audio stream of effect audio is input. If a signal indicating that there is an audio stream of effect audio is input from effect audio decoder 53, system controller 10 proceeds to step S03, and otherwise proceeds to step S04.

  In step S03, the system controller 10 notifies the user that either the sub audio stream or the effect audio stream is present. For the notification, (1) a message from the OSD circuit 37 is displayed, (2) a notification LED provided in the display unit 13 is turned on, (3) a luminance change by the video encoder 33, or these two A combination of two or more. Then, it is determined whether or not the reproduction has ended (step S05). If the reproduction has not ended, the process returns to step S01, and if the reproduction has ended, the process ends.

  On the other hand, in step S04, the notification to the user is terminated. Accordingly, while either the sub audio sound stream or the effect audio sound stream exists, the user is notified that any of them exists.

  If the main audio is set to be output, even if there are sub audio or effect audio sound streams, the user cannot view them. When the detection display process is executed by the system controller 10, the user is notified that either the audio stream of the sub audio or the effect audio exists, so that the user can know the presence.

  FIG. 4 is a flowchart illustrating an example of the flow of the audio output control process. The audio output control process is a process executed by the system controller 10. Referring to FIG. 4, system controller 10 determines whether or not the audio output setting by the user is set to the main audio output (step S11). If the main audio output is set, the process proceeds to step S12; otherwise, the process proceeds to step S21. In step S12, the first switch 55 and the second switch 56 are switched to output the main audio. Specifically, the first switch 55 is switched to the input terminal a side, and the second switch 56 is switched to the input terminal b side. As a result, the audio stream of the main audio is output from the digital output terminals HDMI 42 and S / PDIF 43.

  Next, it is determined whether or not an instruction to turn on mixing is input by the user (step S13). The instruction to turn on the mixing is input to the system controller 10 when the user instructs a mixing button provided in the operation unit 12. The remote controller 14 includes a mixing button. When the user instructs the mixing button of the remote controller 14, an instruction to turn on the mixing is also input to the system controller 10. If an instruction to turn on mixing is input, the process proceeds to step S14. If there is no instruction, the process proceeds to step S18.

  In step S14, an audio stream before the time when there is an instruction to turn on mixing is read. As described above, when the audio output setting is set to the output of the main audio, the user recognizes the presence of the sub audio and the effect audio by being notified of the presence of the sub audio and the effect audio. Therefore, when the user notices the presence of the sub audio and the effect audio and inputs an instruction to turn on the mixing, the sub audio and the effect audio have already passed a certain amount of playback time. Therefore, in order to reproduce the sub audio and the effect audio from the beginning, the audio stream before the time when the instruction to turn on the mixing is issued is read out. Since the audio stream and the video PES are synchronized, the video PES synchronized with the audio stream to be read is read when the audio stream before the time when the instruction to turn on the mixing is read is read. As a result, audio and video are output in synchronization.

The system controller 10 reads out the main audio stream, the sub audio stream, and the effect audio stream before the time when the instruction to turn on the mixing is issued from the data stored in the read buffer 26. If the corresponding data is not stored in the read buffer, the servo circuit 23 is controlled to cause the pickup 21 to read the corresponding data. For the data before the time when the instruction to turn on the mixing is given, the position of the data is determined by one of the following methods.
(1) The position of the data a predetermined time before the time when the instruction to turn on the mixing is given.
(2) The position where either the sub audio or the effect audio is present. The system controller 10 stores the position where the sub audio or the effect audio is present based on the signals input from the sub audio decoder 52 and the effect audio decoder 53, and the position of the stored position is stored. Read main audio, sub audio and effect audio. The position may be a reproduction time or a position recorded on a DVD.
(3) The beginning position of the chapter to which the main audio stream belongs at the time when the instruction is given in step S13.

  In step S15, in order to output the mixed LPCM, the second switch 56 is switched to the input terminal a side. As a result, LPCM in which main audio, sub audio, and effect audio are mixed is output from the digital output terminals HDMI42 and S / PDIF43.

  In step S16, it is determined whether or not an instruction to turn off mixing is input. If an instruction to turn off mixing is input, the process proceeds to step S17. If not, output of the mixed LPCM is continued. The instruction to turn off the mixing is input to the system controller 10 when the user instructs a mixing button provided on the operation unit 12. Instead of inputting an instruction to turn off the mixing by the user, the system controller 10 may detect that neither the sub audio sound stream nor the effect audio sound stream exists. Further, the system controller 10 may detect that the audio stream at the position where the instruction to turn on the mixing is given is input.

  In step S17, in order to output the main audio, the first switch 55 is switched to the input terminal a side, and the second switch 56 is switched to the input terminal b side. As a result, the audio stream of the main audio is output from the digital output terminals HDMI 42 and S / PDIF 43. In step S18, it is determined whether or not the reproduction is finished. If the reproduction is not finished, the process returns to step S13, and if the reproduction is finished, the process is finished.

  On the other hand, in step S21, the system controller 10 determines whether or not the audio output setting by the user is set to sub audio output. If it is set to sub audio output, the process proceeds to step S22; otherwise, the process proceeds to step S31. In step S22, the first switch 55 and the second switch 56 are switched to output sub audio. Specifically, the first switch 55 is switched to the input terminal b side, and the second switch 56 is switched to the input terminal b side. As a result, the audio stream of the sub audio is output from the digital output terminals HDMI 42 and S / PDIF 43.

  Since the processing of step S23 to step S26 is the same as the processing of step S13 to step S16, description thereof will not be repeated here.

  In step S27, in order to output sub audio, the first switch 55 is switched to the input terminal b side, and the second switch 56 is switched to the input terminal b side. As a result, the audio stream of the sub audio is output from the digital output terminals HDMI 42 and S / PDIF 43. In step S28, it is determined whether or not the reproduction is finished. If the reproduction is not finished, the process returns to step S23, and if the reproduction is finished, the process is finished.

  In step S31, the second switch 56 is switched to the input terminal a side in order to output the mixed LPCM. As a result, LPCM in which main audio, sub audio, and effect audio are mixed is output from the digital output terminals HDMI42 and S / PDIF43. In step S32, it is determined whether or not the reproduction is finished. If the reproduction is not finished, the output of the mixed LPCM is continued. If the reproduction is finished, the process is finished.

  As described above, in the disc playback apparatus 100 according to the present embodiment, when the audio stream of the main audio is being output (step S12) and an instruction to turn on mixing is input (step S13), the mixing is performed. The audio streams of the main audio, the sub audio, and the effect audio before the time when the instruction to turn on is read are read (step S14), and the LPCM in which they are mixed is output (step S15). Therefore, the sub audio and the effect audio can be output from the beginning instead of from the middle. Further, in order to turn on the mixing, it is possible to switch from the main audio output to the LPCM output in which the main audio, the sub audio, and the effect audio are mixed by a simple operation such as instructing a mixing button provided in the remote controller 14. .

<Modification>
FIG. 5 is a flowchart showing an example of the flow of the audio output control process in the modification. Referring to FIG. 5, in order to output main audio, system controller 10 switches first switch 55 to input terminal a and switches second switch 56 to input terminal b (step S41). As a result, the audio stream of the main audio is output from the digital output terminals HDMI 42 and S / PDIF 43.

  Then, it is determined whether or not a sub audio stream is input (step S42). If the signal indicating that the sub audio stream is present is input from the sub audio decoder 52, the system controller 10 proceeds to step S44, and if not, proceeds to step S43. In step S43, it is determined whether an audio stream of effect audio has been input. If a signal indicating that an audio stream of effect audio is present is input from the effect audio decoder 53, the system controller 10 proceeds to step S44, and if not, returns the process to step S41.

  In step S44, the second switch 56 is switched to the input terminal a side in order to output the mixed LPCM. As a result, LPCM in which main audio, sub audio, and effect audio are mixed is output from the digital output terminals HDMI42 and S / PDIF43.

  In step S45, it is determined whether or not the reproduction is finished. If the reproduction is not finished, the process returns to step S42, and if the reproduction is finished, the process is finished.

  When the main audio sound stream is read from the DVD 20, the disc playback apparatus 100 in the modification outputs the main audio sound stream (step S 41), and reads the sub audio or effect audio sound stream from the DVD 20. If it has been output (YES in step S42 or YES in step S43), an LPCM in which main audio, sub audio, and effect audio are mixed is output (step S44). Therefore, it is possible to output all of the main audio, sub audio, and effect audio while outputting the audio stream of the main audio from the digital terminals HDMI 42 and S / PDIF 43 as much as possible.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the whole structure of the disc reproducing | regenerating apparatus in one of the embodiments of this invention. It is a block diagram which shows the detailed structure of an audio circuit. It is a flowchart which shows an example of the flow of a detection display process. It is a flowchart which shows an example of the flow of an audio | voice output control process. It is a flowchart which shows an example of another flow of an audio | voice output control process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 System controller, 11 Navigation information analysis part, 12 Operation part, 13 Display part, 14 Remote control, 15 LAN interface, 16 Internet, 17 Computer, 20 DVD, 21 Pickup, 22 Spindle motor, 23 Servo circuit, 24 Demodulation part, 25 Error correction unit, 26 reading buffer, 31 demultiplexer, 32 MPEG video decoder, 33 video encoder, 35 adder, 36 video output terminal, 37 OSD circuit, 38 playback buffer memory, 41 audio circuit, 42 HDMI, 43 S / PDIF, 44 analog output terminal, 51 main audio decoder, 52 sub audio decoder, 53 effect audio decoder, 54 audio mixing engine, 5 The first switching unit, 56 second switcher, 100 a disk reproducing apparatus.

Claims (7)

Reading means for reading a plurality of audio streams synchronized with each other from the recording medium;
Mixing means for mixing the plurality of audio streams and outputting mixing data;
Switching means for switching between a first output mode for outputting a selected stream selected from the plurality of audio streams and a second output mode for outputting the mixing data;
Accepting means for accepting a switching instruction to switch between the first output mode and the second output mode;
Control means for controlling the reading means so as to read the plurality of audio streams before the accepted time point in response to accepting an instruction to switch from the first output mode to the second output mode. Voice playback device. The reading means includes detection means for detecting a position where an audio stream other than the selected stream is present among the plurality of audio streams,
The audio reproduction device according to claim 1, wherein the control unit controls the reading unit to read the plurality of audio streams from the position detected by the detection unit.   The audio reproduction device according to claim 1, wherein the control unit controls the reading unit to read the plurality of audio streams a predetermined time before the time point when the switching instruction is received by the receiving unit.   2. The control unit according to claim 1, wherein the control unit controls the reading unit to read the plurality of audio streams from the beginning of a chapter including the plurality of audio streams read when the switching instruction is received by the receiving unit. The audio reproducing device described.   The control means performs the switching so as to switch from the second output mode to the first mode in response to an audio stream other than the selected stream being read out from the plurality of audio streams by the reading means. The sound reproducing device according to claim 1, which controls the means.   In the second output mode after accepting the switching instruction from the first output mode to the second output mode, the control means next reads the plurality of audio streams at the time of the switching instruction. The sound reproducing apparatus according to claim 1, wherein the switching means is controlled to switch to the first output mode. Reading means for reading a plurality of audio streams synchronized with each other from a recording medium;
Mixing means for mixing the plurality of audio streams and outputting mixing data;
Switching means for switching between a first output mode for outputting a selected stream selected from the plurality of audio streams and a second output mode for outputting the mixing data;
When the selected stream is read by the reading means, the mode is switched to the first output mode, and at least one of the plurality of audio streams other than the selected stream is read by the reading means. And a control means for controlling the switching means so as to switch to the second output mode.

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