JP3877693B2 - Information recording medium playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information recording medium reproducing apparatus for reproducing compressed audio data recorded on an information recording medium.
[0002]
[Prior art]
Conventionally, there is MP3 (Moving Picture Experts Group-2 Audio Layer-3) as a compression technique for compressing audio data. With the MP3 compression technology, the amount of data can be compressed to about one-tenth without substantially degrading the sound quality of the original audio data. Compressed audio data in MP3 format is compact disc recordable (Compact Disc-Recordable (hereinafter referred to as CD-R)), compact disc rewritable (Compact Disc-ReWritable (hereinafter referred to as CD-RW)), and the like. It can be recorded as a file on an information recording medium. MP3 format compressed audio data files (hereinafter referred to as MP3 files) recorded on information recording media such as CD-R and CD-RW are played back by a CD player equipped with an MP3 decoder that decodes MP3 files. (For example, refer to Patent Document 1).
[0003]
An MP3 file is composed of a plurality of frames (hereinafter referred to as MP3 frames). This MP3 frame is composed of a header, side information, main data, and additional data. The MP3 file includes an MP3 file having a fixed bit rate and a variable bit rate MP3 file in which the bit rate changes for each MP3 frame. This bit rate is recorded in the header of the MP3 frame (see Non-Patent Document 1, for example).
[0004]
Since the information in the MP3 frame is recorded in the header of the MP3 frame, in a CD player as disclosed in Patent Document 1, every MP3 frame unit according to the information recorded in the header of the MP3 frame. MP3 files are played by decoding compressed audio data. In addition, since the variable bit rate MP3 file has a different bit rate for each MP3 frame, in a CD player as disclosed in Patent Document 1, the MP3 file is recorded in the header for each MP3 frame from the beginning of the MP3 file. The playback time is calculated by reading the information.
[0005]
On the other hand, for a DJ CD player used by a disc jockey (hereinafter referred to as DJ), a playback start point (hereinafter referred to as A point) and a playback end point (hereinafter referred to as B point) are set. It has a function called loop playback that repeatedly plays back audio data from point A to point B repeatedly. For example, when playing audio data recorded on a music CD (CD-Digital Audio (hereinafter referred to as CD-DA)), the DJ sets the A point by pressing the A point setting button. The CD player for DJ stores the audio data reproduced from the CD-DA in a predetermined time (for example, 5 seconds) from the set point A in the audio data storage unit and is stored in the audio data storage unit. The address (absolute time: minute, second, frame) of the audio data at the position following the audio data (hereinafter referred to as C point) is stored in the address storage unit. The DJ also sets the B point by pressing the B point setting button. When the B setting button is pressed, the DJ CD player stores the address (absolute time: minutes, seconds, frames) at point B in the address storage unit.
[0006]
After setting points A and B, the DJ CD player stops playback and starts reading audio data from point A to point C stored in the audio data storage unit when the loop playback button is pressed. At the same time, the address of the point C stored in the address storage unit is searched, and the optical pickup is moved to the position of the point C address. When the reading of the audio data from the audio data storage unit is completed, the DJ CD player starts reproducing the audio data from the position of the searched point C address. (For example, see Patent Document 2.)
[0007]
[Patent Document 1]
JP 2002-236498 A (Prior art column, FIG. 1)
[Patent Document 2]
JP-A-7-65506 [Non-patent Document 1]
“Interface”, CQ Publishing Co., Ltd., August 1, 2000, p.91-93
[0008]
[Problems to be solved by the invention]
DJ tries to play a loop when playing an MP3 file with variable bit rate using a DJ CD player that can play an information recording medium such as a CD-R on which the MP3 file is recorded. There is a case. In this case, since the DJ CD player does not calculate the playback time by reading the header information for each MP3 frame from the beginning of the MP3 file because the MP3 frame bit rate is not fixed, the compression corresponding to the above point C is performed. The position on the information recording medium where the audio data was recorded could not be retrieved. On the other hand, a DJ CD player as disclosed in Patent Document 2 corresponds to the C point on the CD-DA by reading the absolute time recorded on the CD-DA as described above. It is possible to search for a position to perform. Therefore, the search time required for loop playback of a CD-R, etc., on which a variable bit rate MP3 file is recorded is longer than the search time for audio data recorded on a CD-DA. There is a problem.
[0009]
In addition, when loop playback starts after setting points A and B, if it takes time to search for the position corresponding to point C, all audio data from point A to point C is read from the audio data storage unit. As a result, audio data playback may be interrupted at the point C.
[0010]
The present invention has been made to solve the above-described problem, and when a variable bit rate audio data file (for example, an MP3 file) is being played back, the set audio data is not interrupted. It is an object of the present invention to provide an information recording medium reproducing apparatus capable of repeatedly reproducing (loop reproduction) audio data to be reproduced.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is a reading unit that reads compressed audio data having frame information recorded on an information recording medium, and the compressed audio data read by the reading unit in units of frames. In an information recording medium playback device comprising a decompression unit that decompresses and an output unit that outputs an audio signal decompressed by the decompression unit, a setting for setting a playback start position and a playback end position of the audio signal output by the output unit A first storage unit that stores the audio signal expanded by the expansion unit, reads out the stored audio signal and outputs the stored audio signal to the output unit, and the expansion unit starts from the reproduction start position set by the setting unit in advance. A second storage unit for storing an audio signal expanded at a predetermined time, and playback from a playback start position set by the setting unit The recording position of the header of the frame of the compressed audio data expanded by the expansion unit when the reproduction instruction unit for inputting an instruction to repeatedly reproduce the section of the end position and the instruction for setting the reproduction start position are input from the setting unit A position information storage unit that stores information indicating the above, and a control unit that performs control to detect a frame header each time the decompression unit decompresses compressed audio data recorded in a predetermined number of sectors, and When an instruction to repeatedly reproduce is input from the reproduction instruction unit, the control unit reads the audio signal stored in the second storage unit, outputs the audio signal from the output unit, and sends the audio signal stored in the reading unit to the position information storage unit. The setting unit is configured to start reading compressed audio data from the stored recording position of the header and to decompress the compressed audio data to the decompressing unit. And a control for storing the audio signal such stretched from a more set reproduction start position in the first storage unit, the audio signals subsequent to the audio signal when reading the audio signal from the second storage unit is completed Control is performed to read from the first storage unit.
[0012]
According to a second aspect of the present invention, there is provided a reading unit that reads compressed audio data having frame information recorded on an information recording medium, a decompressing unit that decompresses the compressed audio data read by the reading unit in units of frames, In an information recording medium playback device including an output unit that outputs an audio signal expanded by the expansion unit, a setting unit that sets a reproduction start position and a reproduction end position of the audio data output by the output unit, and the expansion unit A first storage unit that stores the expanded audio signal, reads the stored audio signal, and outputs the audio signal to the output unit; and the expansion unit expands at a predetermined time from the reproduction start position set by the setting unit A second storage unit for storing the audio signal, and a section from the reproduction start position to the reproduction end position set by the setting unit. Returns a reproduction instruction unit for inputting an instruction to reproduce the just before the storing of the audio signal ends in the second storage unit, stores information indicating the recording position of the header of the frame of compressed audio data to which the extension portion is stretched A position information storage unit, and a control unit that performs control to detect a frame header each time the decompression unit decompresses compressed audio data recorded in a predetermined number of sectors. When an instruction to repeatedly reproduce is input from the reproduction instruction unit, the audio signal stored in the second storage unit is read out and output from the output unit, and the header stored in the position information storage unit is stored in the reading unit. The reading of the compressed audio data is started from the recording position, the compressed audio data is decompressed by the decompression unit, and the playback start set by the setting unit is started. The audio signal the stretch from position time said predetermined has elapsed from the position to the control for storing in the first storage unit, and the reading of the audio signal from the second storage unit is completed the first The audio signal stored in the storage unit is controlled to be read out.
[0013]
The invention according to claim 3 of the present application is the information recording medium reproducing apparatus according to claim 1 or 2, wherein the position information storage unit is configured to store a frame for each predetermined number of sectors. A storage table unit is provided for storing information indicating a reproduction time when a header is detected and a recording position of the header.
[0014]
According to a fourth aspect of the present invention, in the information recording medium reproducing device according to any one of the first to third aspects, the compressed audio data recorded on the information recording medium has a variable bit rate. It is MP3 format compressed audio data.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an information recording medium reproducing apparatus according to an embodiment of the present invention. In addition to CD-DA, the information recording medium playback apparatus of this embodiment can play CD-Rs and CD-RWs with MP3 files recorded thereon, and is a DJ CD player with a loop playback function. It is.
[0016]
In FIG. 1, 1 is a spindle motor, 2 is a servo control unit, 3 is an optical pickup, 4 is a reproduction amplifier, 5 is a digital signal processor (hereinafter referred to as DSP), 6 is an audio data storage unit, 7 is a digital-to-analog converter (hereinafter referred to as DAC), 8 is an amplifier, 10 is a control unit, 11 is an operation unit, 12 is a display unit, and 13 is a storage unit. The CD is CD-DA, CD-R, CD-RW, or the like.
[0017]
The turntable fixed to the spindle motor 1 is loaded with a CD. When an instruction to start reproduction is input from the operation unit 11, the servo control unit 2 performs control to drive the spindle motor 1 to rotate at a predetermined linear velocity. The servo control unit 2 controls a focus servo circuit and a tracking servo circuit (not shown) in order to correctly trace the laser light from the optical pickup 3 to the CD pit row.
[0018]
Digital audio data read by the optical pickup 3 is shaped and amplified by the reproduction amplifier 4 and input to the DSP 5. The DSP 5 includes a signal processing unit and an MP3 decoder. When the digital audio data input to the DSP 5 is uncompressed audio data reproduced from a CD-DA or the like, the DSP 5 uses the signal processing unit to demodulate the uncompressed audio data, demodulate the subcode data, focus error signal and tracking error. An error signal such as a signal and a synchronization signal are extracted, and digital audio data is input to the audio data storage unit 6. Further, the DSP 5 separates time information from the input uncompressed audio data and inputs it to the control unit 10. When the digital audio data input to the DSP 5 is MP3 format compressed audio data, the MP3 format compressed audio data is expanded by the MP3 decoder built in the DSP 5 and the expanded digital audio data is input to the audio data storage unit 6. .
[0019]
The audio data storage unit 6 has a normal playback storage area for storing digital audio data input from the DSP 5 (for example, storing digital audio data for 10 seconds) and an A point setting button of the operation unit 11 to be described later. A loop playback storage area for storing digital audio data input from the DSP 5 at a predetermined time (for example, 5 seconds) from time to time is provided. The digital audio data stored in the audio data storage unit 6 is read by the DSP 5 and input to the DAC 7. The DAC 7 converts the digital audio data into an analog audio signal and inputs the analog audio signal to the amplifier 8. The analog audio signal output from the DAC 7 is output from a speaker that is amplified by the amplifier 8 and connected to an output terminal included in the output unit 9.
[0020]
An operation unit 11 connected to the control unit 10 sets a playback start button for starting playback of audio data, a playback stop button, a fast forward button, a fast reverse button, a song selection button, and a playback start point (A point) for loop playback. A point setting button, B point setting button to set the playback end point (B point) of loop playback, loop playback button to start loop playback of audio data played from the set A point to B point, etc. ing. A display unit 12 connected to the control unit 10 displays the reproduction time (minutes, seconds, frames) of the currently reproduced track, and displays the track number and the like. The storage unit 13 connected to the control unit 10 includes a storage table and a loop reproduction management table described later.
[0021]
When playing back a CD on which an MP3 file is recorded, the control unit 10 calculates a playback time (minute, second, frame) from information recorded in the header of the MP3 frame, and displays the calculated playback time on the display unit 12. Control display. Further, the control unit 10 acquires recording position information of the sector position and byte position where the decompressed compressed audio data is recorded by using an ATAPI (Advanced Technology Attachment Packet Interface) bus (not shown). Here, the sector position and the byte position are physical positions on the CD, and when the physical format for recording the MP3 file on the CD-R is set to CD-ROM mode-1, the MP3 file has 2352 bytes. Each sector is divided and recorded.
[0022]
The playback operation of a CD on which a variable bit rate MP3 file is recorded in the DJ CD player of this embodiment will be described.
[0023]
The control unit 10 detects the header of the first MP3 frame of the MP3 file from which playback has started, and acquires the recording position information of the sector position and byte position where the detected header is recorded by using the above-described ATAPI bus. The control unit 10 performs control to store the acquired sector position and byte position in the storage table of the storage unit 13. Further, the control unit 10 performs control to store the playback time from the start of playback to the detection of the header of the first MP3 frame of the MP3 file in the storage table of the storage unit 13. That is, the control unit 10 reproduces the recording position information (sector position and byte position) where the header of the first MP3 frame of the MP3 file is recorded and the compressed audio data of the MP3 file until the header is detected. Control is performed to store the time in the storage table of the storage unit 13 in association with the time. The playback time when detecting the header of the first MP3 frame of the MP3 file is 0 minute 0 second 0 frame.
[0024]
Each time the compressed audio data of the MP3 file recorded in the predetermined number of sectors by the DSP 5 is expanded from the sector in which the header of the MP3 frame at the head of the detected MP3 file is recorded, the control unit 10 reads the MP3 frame. Detect headers. In this embodiment, the predetermined number of sectors is assumed to be 20 sectors. The control unit 10 detects the header from the sector position and byte position where the header of the MP3 frame to be detected first in the expanded 20th sector is recorded, and the reproduction of the compressed audio data of the MP3 file. The reproduction time until is stored in the storage table of the storage unit 13.
[0025]
FIG. 2 is a diagram illustrating a storage table of the storage unit 13. As shown in FIG. 2, the storage table includes seven tables, and the sector position and byte position detected by the control unit 10 from the table 1 and reproduction time data are stored. When the sector position, byte position, and reproduction time data detected by the control unit 10 are stored in all tables, the control unit 10 newly reads the sector position, byte position, and reproduction time detected by the control unit 10 from the table 1. Control to store the data.
[0026]
Until the reproduction of one MP3 file is completed, the control unit 10 is the 20th sector from the sector (for example, the 140th sector in Table 1 shown in FIG. 2) from which the MP3 frame header is detected as described above. Sectors (for example, 160 sectors in Table 2 shown in FIG. 2) are detected. The control unit 10 stores the recording position where the header of the MP3 frame to be reproduced first in the sector of the detected sector is recorded and the reproduction time at the recording position of the header in the table of the storage unit 13 as shown in FIG. To control.
[0027]
In the DJ CD player of the present embodiment, a description will be given of a first embodiment of a playback operation in which a section from a set point A to a point B is loop-played when an MP3 file having a variable bit rate is being played.
[0028]
When an MP3 file of variable bit rate is being played, if the A point setting button of the operation unit 11 is pressed, the control unit 10 causes the playback time when the A point setting button is pressed (hereinafter referred to as loop playback start). Time)) is stored in the loop reproduction management table of the storage unit 13, and the sector position and byte position of the header detected and stored in the storage table of the storage unit 13 immediately before the A point setting button is pressed. The playback time is stored in the loop playback management table of the storage unit 13 as loop playback management data. When the B point setting button of the operation unit 11 is pressed after setting the A point, the control unit 10 stores the reproduction time when the B point setting button is pressed (hereinafter referred to as loop reproduction end time). Control to store in the loop reproduction management table of the unit 13 is performed. FIG. 3 is a diagram showing a loop reproduction management table of the storage unit 13 of the first embodiment.
[0029]
For example, when the A point setting button is pressed, when the playback time from the start of playback calculated by the control unit 10 to when the A point setting button is pressed is 0 minutes 13 seconds 70 frames, the control unit 10 As shown in FIG. 3, the loop reproduction start time (0 minute 13 seconds 70 frames) is stored in the loop reproduction management table of the storage unit 13. The control unit 10 also reads the sector position (180 sectors), byte position (856 bytes), and playback time (0 minute 13) stored in the table 4 of the storage table of the storage unit 13 immediately before the point A setting button is pressed. 11 frames per second) is stored as loop reproduction management data in the loop reproduction management table of the storage unit 13 as shown in FIG. After setting the A point, when the B point setting button of the operation unit 11 is pressed, the playback time from the start of playback calculated by the control unit 10 until the B point setting button is pressed is 0 minute 32 seconds 14 frames Then, the control unit 10 performs control to store the loop playback end time (0 minute 32 seconds 14 frames) in the loop playback management table of the storage unit 13 as shown in FIG.
[0030]
On the other hand, when the A point setting button of the operation unit 11 is pressed, the control unit 10 inputs from the DSP 5 at a predetermined time (for example, 5 seconds) from when the A point setting button is pressed as described above. The digital audio data thus recorded is controlled to be stored in the loop reproduction storage area of the audio data storage unit 6. The digital audio data stored in the loop playback storage area of the audio data storage unit 6 is also stored in the normal playback storage area of the audio data storage unit 6 described above.
[0031]
After setting the points A and B, when the loop playback button of the operation unit 11 is pressed, the control unit 10 controls the optical pickup 3 to stop reading the variable bit rate MP3 file from the CD, and the audio The digital audio data stored in the loop reproduction storage area of the data storage unit 6 is controlled to be read. Further, the control unit controls the servo control unit 2 to search for a recording position corresponding to the sector position and byte position of the loop reproduction management data stored in the loop reproduction management table of the storage unit 13. When the control unit 10 searches for the recording position corresponding to the sector position and byte position of the loop reproduction management data, the control unit 10 reads the MP3 file from the recording position searched by the optical pickup 3 and controls to start reproduction. After starting playback, the control unit 10 calculates the playback time of the MP3 file that has started playback from the playback time (0 minutes 13 seconds 11 frames) of the loop playback management data stored in the loop playback management table of the storage unit 13. When the calculated playback time reaches the loop playback start time (0 minute 13 seconds 70 frames) stored in the loop playback management table, the control unit 10 stores the digital audio data in the normal playback storage area of the audio data storage unit 6. Start memorizing control. At this time, the control unit 10 performs control to reproduce the MP3 file recorded on the CD at a reproduction speed faster than the normal reproduction speed.
[0032]
FIG. 4 is a diagram showing a storage state of audio data in the digital audio data storage unit 6 when loop reproduction is started.
As shown in FIG. 4 (a), the normal playback storage area has the same digital audio data stored in the loop playback storage area until the reading of the digital audio data stored in the loop playback storage area is completed. Digital audio data and digital audio data following the digital audio data are stored. When the reading of the digital audio data stored in the loop reproduction storage area is completed, the control unit 10 stores the digital audio data stored in the normal reproduction storage area from the position (point C) following the digital audio data read from the loop reproduction storage area. Controls reading digital audio data. Here, the normal reproduction storage area and the loop reproduction storage area are assigned the same address, and the same digital audio data is stored in the storage areas from address 1 to address 200 shown in FIG. Yes. Accordingly, when the reading of the digital audio data stored in the loop reproduction storage area is completed, the control unit 10 controls to read out the digital audio data stored from the address 201 assigned to the normal reproduction storage area. Therefore, the digital audio data following the digital audio data read from the loop reproduction storage area can be read from the normal reproduction storage area without interruption.
[0033]
After starting the loop playback, when the calculated playback time reaches the loop playback end time (0 minute 32 seconds 14 frames) stored in the loop playback management table, the control unit 10 stops reading the MP3 file from the CD again. Control to read out the digital audio data stored in the loop reproduction storage area of the audio data storage unit 6 is started, and the control is performed as described above. As described above, the DJ CD player of this embodiment can search for the set A point in a short time when playing an MP3 file having a variable bit rate, so that the audio data to be played is interrupted. The section from point A to point B can be loop-played without any problem.
[0034]
Next, a description will be given of a second embodiment of the reproducing operation in which the section from the set point A to the point B is reproduced in a loop when the MP3 file having a variable bit rate is being reproduced in the DJ CD player of the present embodiment. To do.
[0035]
In the second embodiment, immediately before the digital audio data is stored for a predetermined time (for example, 5 seconds) from when the point A setting button is pressed in the loop reproduction storage area of the audio data storage unit 6. The sector position, byte position, and playback time of the header detected by the control unit 10 and stored in the storage table of the storage unit 13 are stored in the loop playback management table of the storage unit 13 as loop playback management data. FIG. 5 is a diagram showing a loop reproduction management table of the storage unit 13 of the second embodiment.
[0036]
As shown in FIG. 5, when the loop playback start time is 0 minute 9 seconds 00 frame in the loop playback management table of the storage unit 13, the playback time when the digital audio data storage ends in the loop playback storage area is It becomes 0 minute 14 seconds 00 frame obtained by adding the storage time (5 seconds) of the loop reproduction storage area to 0 minute 9 seconds 00 frame. Loop reproduction management data is determined from the reproduction time of 0 minute 14 seconds 00 frame and the reproduction time stored in each table of the storage table of the storage unit 13 shown in FIG. Since the playback time when the storage of the digital audio data is completed in the loop playback storage area is 0 minute 14 seconds 00 frame, it is detected immediately before this 0 minute 14 seconds 00 frame and stored in the storage table of the storage unit 13. The table in which the sector position, byte position, and reproduction time of the header are stored is the storage table 3 shown in FIG. Accordingly, the loop reproduction management data stored in the loop reproduction management table of the storage unit 13 is 180 sectors, 856 bytes, and 0 minutes, 13 seconds, and 11 frames, as shown in FIG.
[0037]
The description of the operation for storing the loop playback end time in the loop playback management table of the storage unit 13 and the operation for storing the digital audio data in the loop playback storage area of the audio data storage unit 6 is the same as in the first embodiment. Since there is, explanation is omitted.
[0038]
After setting the points A and B, when the loop playback button of the operation unit 11 is pressed, the control unit 10 controls the optical pickup 3 to stop reading the variable bit rate MP3 file from the CD, and the audio The digital audio data stored in the loop reproduction storage area of the data storage unit 6 is controlled to be read. Further, the control unit controls the servo control unit 2 so as to detect a recording position corresponding to the sector position and byte position of the loop reproduction management data stored in the loop reproduction management table of the storage unit 13. When the control unit 10 detects the recording position corresponding to the sector position and byte position of the loop reproduction management data, the control unit 10 reads the MP3 file from the recording position detected by the optical pickup 3 and controls to start reproduction. After starting playback, the control unit 10 calculates the playback time of the MP3 file that has started playback from the playback time (0 minutes 13 seconds 11 frames) of the loop playback management data stored in the loop playback management table of the storage unit 13. When the calculated playback time reaches 0 minutes 14 seconds 00 frames, the control unit 10 stores the digital audio data from the address 1 of the normal playback storage area of the audio data storage unit 6 as shown in FIG. To control. Alternatively, as shown in FIG. 4C, the control unit 10 stores the digital audio data from the address 201 of the normal playback storage area of the audio data storage unit 6 when the calculated playback time reaches 0 minutes 14 seconds 00 frames. Control may be performed.
[0039]
When the reading of the digital audio data stored in the loop reproduction storage area is completed, the control unit 10 controls to read the digital audio data stored from the address 1 or the address 201 in the normal reproduction storage area. Therefore, the digital audio data stored in the normal playback storage area can be read from the position (point C) following the digital audio data read from the loop playback storage area.
[0040]
After starting the loop reproduction, when the calculated reproduction time reaches the loop reproduction end time (0 minute 20 seconds 22 frames shown in FIG. 5) stored in the loop reproduction management table, the control unit 10 again reads the MP3 file from the CD. Is started to read out the digital audio data stored in the loop reproduction storage area of the audio data storage unit 6, and the control is performed as described above. As described above, the DJ CD player of the present embodiment can search the position where the digital audio data following the digital audio data stored in the loop reproduction storage area is recorded in a short time, so that the audio to be reproduced is reproduced. The section from point A to point B can be played back in a loop without data interruption.
[0041]
【The invention's effect】
According to the present invention, when a variable bit rate audio data file (for example, an MP3 file) is being played back, the audio data to be played back is repeatedly played back (looped) without being interrupted. It is possible to provide an information recording medium reproducing apparatus capable of reproducing).
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a DJ CD player according to an embodiment of the present invention.
FIG. 2 is a diagram showing a storage table provided in the storage unit 13;
FIG. 3 is a diagram illustrating a cue point supplementary table according to the first embodiment.
FIG. 4 is a diagram showing a storage state of digital audio data in the audio data storage unit 6. FIG. 5 is a diagram showing a cue point supplement table of the second embodiment.
[Explanation of symbols]
1 Spindle motor 2 Servo controller 3 Optical pickup 4 Playback amplifier 5 DSP
6 Audio data storage 7 DAC
8 Amplifier 9 Output unit 10 Control unit 11 Operation unit 12 Display unit 13 Storage unit

Claims (4)

A reading unit that reads compressed audio data having frame information recorded on an information recording medium, a decompressing unit that decompresses compressed audio data read by the reading unit in units of frames, and an output unit that outputs an audio signal decompressed by the decompressing unit In an information recording medium playback device comprising:
A setting unit for setting a reproduction start position and a reproduction end position of the audio signal output by the output unit;
A first storage unit that stores the audio signal expanded by the expansion unit, reads the stored audio signal, and outputs the audio signal to the output unit;
A second storage unit for storing an audio signal expanded by the expansion unit at a predetermined time from the reproduction start position set by the setting unit;
A reproduction instruction unit for inputting an instruction to repeatedly reproduce a section from the reproduction start position to the reproduction end position set by the setting unit;
A position information storage unit for storing information indicating a recording position of a header of a frame of compressed audio data expanded by the expansion unit when an instruction to set a reproduction start position is input from the setting unit;
A controller for controlling the detection of a frame header each time the decompression unit decompresses compressed audio data recorded in a predetermined number of sectors;
When an instruction to repeatedly reproduce is input from the reproduction instruction unit, the control unit reads an audio signal stored in the second storage unit, outputs the audio signal from the output unit, and outputs the position information storage unit to the reading unit. The compressed audio data is started to be read from the recording position of the header stored in the memory, the compressed audio data is decompressed by the decompression unit, and the decompressed audio signal is reproduced from the reproduction start position set by the setting unit. Information recording medium reproduction, wherein control is performed to store data in a first storage unit, and control is performed to read out an audio signal following the audio signal from the first storage unit when reading of the audio signal from the second storage unit is completed. apparatus. A reading unit that reads compressed audio data having frame information recorded on an information recording medium, a decompressing unit that decompresses compressed audio data read by the reading unit in units of frames, and an output unit that outputs an audio signal decompressed by the decompressing unit In an information recording medium playback device comprising:
A setting unit for setting a reproduction start position and a reproduction end position of the audio data output by the output unit;
A first storage unit that stores the audio signal expanded by the expansion unit, reads the stored audio signal, and outputs the audio signal to the output unit;
A second storage for storing the audio signal expanded by the expansion unit at a predetermined time from the reproduction start position set by the setting unit;
A reproduction instruction unit for inputting an instruction to repeatedly reproduce a section from the reproduction start position to the reproduction end position set by the setting unit;
A position information storage unit that stores information indicating a recording position of a header of a frame of compressed audio data decompressed by the decompression unit immediately before storage of the audio signal in the second storage unit;
A controller for controlling the detection of a frame header each time the decompression unit decompresses compressed audio data recorded in a predetermined number of sectors;
When an instruction to repeatedly reproduce is input from the reproduction instruction unit, the control unit reads an audio signal stored in the second storage unit, outputs the audio signal from the output unit, and outputs the position information storage unit to the reading unit. From the position where the predetermined time has elapsed from the reproduction start position set by the setting unit by starting reading the compressed audio data from the header recording position stored in the Control to store the expanded audio signal in the first storage unit, and control to read out the audio signal stored in the first storage unit when reading of the audio signal from the second storage unit is completed. An information recording medium reproducing apparatus characterized by the above. The information recording medium reproducing device according to claim 1 or 2,
The position information storage unit includes a storage table unit that stores information indicating a reproduction time and a recording position of the header when the control unit detects a frame header for each predetermined number of sectors. An information recording medium reproducing apparatus. 4. The information recording medium playback apparatus according to claim 1, wherein the compressed audio data recorded on the information recording medium is MP3 format compressed audio data having a variable bit rate. Information recording medium reproducing apparatus.

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