JP2003331524A - Reproducing device and reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously reproduce music data by removing music data and compressed empty data from compressed data compressed by a frame unit. <P>SOLUTION: A computer 21 reads compressed data from an optical disk 1, and expands the read data to store it in a buffer 20a. The computer 21 detects the head and tail tags of the file of music data. Upon the acquisition of the sizes of the detected head and tail tags, the computer 21 obtains the storage position information of the head and tail data of the file to fetch the data from the head to the tail of the file from the buffer 20a, and stores the data in a ring buffer 20b. The computer 21 reads the data stored in the ring buffer 20b to reproduce the data. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reproducing apparatus and a reproducing method.

[0002]

2. Description of the Related Art An optical disc such as a CD-ROM has
Music data is compressed and recorded in frame (2048 Byte) units. The reproducing device expands the compressed data recorded on the optical disc in frame units to reproduce the music data.

[0003]

When the music data is compressed in frame units, if the size of one music data does not match the size of the frame which is the compression unit, unnecessary data is also compressed together with the music data. Will be. Then, when this compressed data is decompressed, empty data exists between the music data and the music data.
Even if an attempt is made to continuously reproduce a plurality of pieces of music data in the presence of such empty data, a silent portion is generated between the pieces of music, resulting in discontinuous reproduction.

The present invention has been made in view of such conventional problems, and it is an object of the present invention to provide a reproducing apparatus and a reproducing method capable of continuously reproducing music data obtained by decompressing compressed data. To aim.

[0005]

In order to achieve this object, a reproducing apparatus according to a first aspect of the present invention is a reproducing apparatus for reproducing music data which is compressed and recorded in a recording medium in units of frames. Decompressing the compressed data recorded on the recording medium in frame units, and decompressed data storing means for storing the decompressed data, and the data stored in the decompressed data storing means are music data, Music data extracting means for determining whether the data is empty data compressed in frame units together with data, and extracting only music data based on the determination result, and data reproduction for reproducing the music data extracted by the music data extracting means And means.

The song data extracting means analyzes the data stored in the decompressed data storage means to identify a leading identifier for identifying the leading data of the song data and an ending identifier for identifying the ending data of the song, It is determined that the data recorded at the recording position between the head identifier and the tail identifier is music data, and the data recorded at the recording position between the tail identifier and the head identifier is null data. Alternatively, it may be configured to extract only the determined song data.

The music piece data extracting means may be provided with music piece data storing means for storing the music piece data extracted from the decompressed data storing means and continuously reading it when reproducing.

The recording medium may be an optical disc, and may reproduce the music data recorded on the optical disc in a frame unit.

The recording medium may be a semiconductor recording medium composed of a semiconductor, and may reproduce music data recorded in the semiconductor recording medium compressed in frame units.

A reproducing method according to a second aspect of the present invention comprises the steps of decompressing compressed data recorded on a recording medium in frame units and storing the decompressed data; and analyzing the stored data, Based on the analysis result, the stored data is a song data, it is determined whether the song data is empty data compressed in frame units together with the step of extracting only the song data based on the determination result, A step of reproducing the extracted music piece data.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the embodiments of the present invention, the reproducing apparatus will be described as an optical disk apparatus for reproducing data recorded on an optical disk such as a CD-ROM.

FIG. 1 shows the configuration of the optical disk device according to the present embodiment. The optical disk device is a spindle motor 1
1, an optical pickup 12, a thread motor 13,
Servo circuit 14, drivers 15 and 16, RF (Radi
o Frequency) matrix amplifier 17 and decoder 18
, A TOC memory 19, a memory 20, a computer 21, and a controller 22.

The optical disc 1 is, for example, a CD-ROM.
It is a disk-shaped recording medium such as (Compact Disk Read Only Memory).

As shown in FIG. 2, the optical disc 1 has a lead-in area and a PVD (Primary Volume) from the inner circumference side.
Description) area, a path table, a data area, and a lead-out area.

User data such as music data is recorded in the data area. One piece of music data is collected as one file, and the file is divided into frames and compressed.

The lead-in area is an area where data reading is started, and the lead-in area has a TOC (Tabl
e Of Contents area is provided. In this TOC area, TOC is recorded as information for managing the frame data recorded in the data area.

The lead-out area is an area for ending the reading of data. PVD indicates layer information and the like of music data and the like recorded in the data area. The path table is a table in which address information of each music data recorded in the data area is recorded.

Returning to FIG. 1, the spindle motor 11 is a motor for rotating the optical disc 1. The optical pickup 12 is for reading data recorded on the optical disc 1, and includes a light emitting element (not shown), an actuator (not shown), and a photodetector (not shown).

The light emitting element is composed of a laser diode or the like and emits laser light. The actuator supports the objective lens and adjusts the attitude of the objective lens. The photodetector detects the return light reflected by the optical disc 1 by the laser light emitted from the light emitting element, and converts the detected return light into an electric signal having a signal level corresponding to its intensity. The optical pickup 12 performs signal processing on the converted electric signal to obtain a tracking error (TE).
It outputs a signal, a focus error (FE) signal, an RF signal, and the like.

The thread motor 13 is the optical pickup 1
2 is a motor for moving the optical disc 1 in the radial direction of the optical disc 1.

The servo circuit 14 generates a tracking control signal and a focus control signal that bring the signal levels of the respective signals close to 0 based on the TE and FE signals output from the optical pickup 12. Further, the servo circuit 14 adjusts the frequency of the RF signal to an appropriate value,
A rotation control signal for controlling the rotation of the spindle motor 11 is generated.

The driver 15 applies a control voltage having a voltage level set based on the signal level of the sled control signal generated by the servo circuit 14 to the sled motor 13, thereby controlling the sled motor 13.

The driver 16 controls the rotation of the spindle motor 11 based on the rotation control signal generated by the servo circuit 14.

The RF matrix amplifier 17 amplifies the tracking control signal and the focus control signal generated by the servo circuit 14 and controls the attitude of the objective lens via the actuator in the optical pickup 12. The RF matrix amplifier 17 also acquires information indicating the absolute (elapsed) time of the song data, the elapsed time for each song, and the song number.

The decoder 18 decodes and reproduces music data. The TOC memory 19 stores the data read from the TOC area of the optical disc 1,
RAM (Random Access Memory) is a memory for compressing and storing the path table information read from D.
It is composed of such semiconductors.

The memory 20 is a DRAM (Dynamic Random
Access memory) and the like, and includes a buffer 20a and a ring buffer 20b. The buffer 20a is for storing the data read from the optical disc 1. The ring buffer 20b is
The data of the file excluding the tag information etc. is stored in the buffer 20a
It is for transferring and storing from.

The computer 21 is a CPU (Central Pr
Ocessing Unit), ROM (Read Only Memory), RA
Servo circuit 14 including M (Random Access Memory)
And the RF matrix amplifier 17 are controlled.

Further, the computer 21 reads the data from the optical disc 1 into the buffer 20a, and the buffer 2
The read process from 0a to the ring buffer 20b and the data read process from the ring buffer 20b are performed. The controller 22 controls the entire optical disc device. Further, the controller 22 outputs the music data decoded by the decoder 18 to a speaker (not shown) after digital-analog conversion.

Next, the operation of the optical disk device according to this embodiment will be described. When the optical disk 1 is set on the turntable (not shown), the computer 21 turns off the servo and the spindle motor 11 is turned on via the driver 16.
To rotate.

The computer 21 uses the sled motor 13
The optical pickup 12 is moved to the initial position (the innermost circumference of the optical disc 1) via the, and the servo is turned on.

The light emitting element provided in the optical pickup 12 irradiates the optical disk 1 with a light beam, and the photodetector detects and detects the return light reflected by the optical disk 1 from the laser light emitted from the light emitting element. Return light,
It is converted into an electric signal having a signal level corresponding to the strength. Then, the optical pickup 12 outputs the TE, FE, and RF signals generated based on the converted electric signal.

When the servo is turned on, the servo circuit 14
A tracking control signal and a focus control signal are generated based on the TE signal and the FE signal output from the optical pickup 12, and the generated tracking control signal and focus control signal are output to the driver 16.

The RF matrix amplifier 17 controls the attitude of the objective lens via the actuator in the optical pickup 12 based on the tracking control signal and the focus control signal output from the servo circuit 14. As a result, tracking control and focus control are performed.

Further, the servo circuit 14 supplies the rotation control signal generated based on the RF signal output from the optical pickup 12 to the driver 16. The driver 16 controls the spindle motor 11 based on the supplied rotation control signal, and the spindle motor 11 rotates the optical disc 1 so that the linear velocity of each track of the optical disc 1 becomes constant.

The servo circuit 14 also generates a thread control signal based on the TE signal. Computer 21
Controls the sled motor 13 via the driver 15. The thread motor 13 transfers the optical pickup 12 to the data reading position in the radial direction of the optical disc 1.

The optical pickup 12 is the TO of the optical disc 1.
The TOC recorded in the area C is read out, and the computer 21 reads the TOC read out by the optical pickup 12 into the TOC.
It is stored in the OC memory 19. The optical pickup 12 reads out the path table information recorded on the PVD of the optical disc 1, and the computer 21 compresses the path table information read out by the optical pickup 12 into the TOC memory 19 and stores it.

The computer 21 reads the frame data from the data area of the optical disc 1 based on the path table information stored in the TOC memory 19.

FIG. 3 shows the processing when reading frame data.
It will be described based on the flowchart shown in FIG. The computer 21 determines whether or not there is a storage space in the buffer 20a (step S11). When it is determined that there is no storage space in the buffer 20a (No in step S11), the computer 21 ends this process.

When it is determined that the buffer 20a has a storage space (Yes in step S11), the computer 21 specifies the storage position of the frame data in the data area based on the TOC stored in the TOC memory 19. Then, the computer 21 reads the frame data from the data area of the optical disc 1 (step S12).

The computer 21 expands the read frame data (step S13). Computer 2
When the frame data is expanded, 1 stores the expanded data in the buffer 20a (step S14).

The computer 21 stores the data in the buffer 2
When it is stored in 0a, it is determined whether or not there is next data to be read from the optical disc 1 (step S15). If it is determined that there is data to be read from the optical disc 1 (Yes in step S15), the computer 2
1 executes the processing of steps S11 to S14.

When it is determined that there is no data to be read from the optical disc 1 (No in step S15), the computer 21 ends this process.

When the data is read from the optical disk 1 in this way, the buffer 20a stores the expanded data as shown in FIG. In this example,
Data of the decompressed file 1 is stored in the areas of frames 1 to n.

A head tag and an end tag are recorded at the recording position immediately before the head data of each file and at the recording position next to the tail data, respectively. “ID3v2” indicates the start tag of the file, and “ID3v1” indicates the end tag of the file. The top tag and the end tag also include additional information such as a song title.

Additional information can be freely written in the tag information of the head tag. Therefore, the data size of the tag information of the head tag changes depending on the amount of information. Therefore, the tag information of the head tag also includes its size information. On the other hand, the data size of the tag information of the end tag is constant.

As described above, when the compressed frame data is expanded and the file size does not match a multiple of the size of one frame, unnecessary data unrelated to the music data is also compressed. To be done. When this frame data is expanded, an empty area is created. In this example,
There is an empty area in the area of frame n.

Next, the computer 21 uses the buffer 20.
The process of fetching data from a to the ring buffer 20b is performed to remove the empty area, tag information, and the like. This process will be described based on the flowchart shown in FIG.

The computer 21 analyzes the data and detects the head tag stored in the buffer 20a (step S21). The computer 21 analyzes the tag information of the detected start tag and acquires the size of the start tag (step S22).

When the computer 21 acquires the size of the head tag, the computer 21 acquires the information on the storage position of the head data of the file at the storage position next to the storage position where the tag information of the head tag is stored. (Step S2
3). The computer 21 stores the acquired information on the storage position of the leading data in the RAM.

When the information on the storage position of the head data is stored in the RAM, the computer 21 next detects the tail tag of the file (step S24).

When the end tag is detected, the computer 2
1 uses the storage position immediately before the detected storage position of the end tag as the storage position of the end data of the file and acquires the information of the storage position (step S25). The computer 21 uses the information on the storage position of the acquired tail data in the RAM.
Remember.

When the information on the storage positions of the head data and the tail data is stored in the RAM, the computer 21 determines whether or not there is a space for storing the data in the ring buffer 20b (step S26).

When it is determined that there is no storage space in the ring buffer 20b (No in step S26), the computer 21 once ends this processing. If the ring buffer 20b has a storage space,
The computer 21 executes this process again.

When it is determined that the ring buffer 20b has a storage space (Yes in step S26),
The computer 21 sequentially fetches the data from the buffer 20a and stores it in the ring buffer 20b based on the stored information on the storage positions of the head data and the tail data (step S27).

The computer 21 determines whether or not the file import is completed (step S28). If the end data is not stored in the ring buffer 20b, the computer 21 determines that the file loading is not completed (No in step S28), and continues storing the data in the ring buffer 20b (step S27). .

If the end data is stored in the ring buffer 20b, the computer 21 determines that the file loading is completed (Yes in step S28).
s). In this case, the computer 21 erases the data already captured from the buffer 20a, and determines whether the data to be captured is stored in the buffer 20a (step S29).

When it is determined that the data to be fetched is stored in the buffer 20a (Yes in step S29), the computer 21 proceeds to steps S21 to 28.
The process of is executed again.

When it is determined that the data to be fetched is not stored in the buffer 20a (No in step S29), the computer 21 ends this process.

This process will be further described with reference to FIG. The computer 21 analyzes the data and first detects the head tag “ID3v2”. When the head tag “ID3v2” is detected, the computer 21 acquires the size of the head tag included in the tag information of the head tag “ID3v2”.

When the size of the head tag is acquired, the computer 21 uses the data stored in the memory position immediately after the head tag as the head data of the file 1 and acquires the information of the memory position.

The computer 21 stores the information on the storage location in the RAM. Information on the storage location of the first data is R
When stored in the AM, the computer 21 next detects the end tag "ID3v1".

Since the size of the end tag "ID3v1" is fixed, the computer 21 uses the end tag "ID3v1".
The data stored in the storage position immediately before the storage position "1" is used as the end data of the file 1, and the information of the storage position is acquired and stored in the RAM.

When the computer 21 stores the storage position information of the start data and the end data in the RAM, the data from the start to the end of the frame 1 is sequentially stored in the ring buffer 20b based on the stored storage position information. Remember.

When the storage of the data of the file 1 in the ring buffer 20b is completed in this way, the computer 21 similarly fetches the data of the file 2 from the buffer 20a. The computer 21 stores the head data of the captured file 2 in the storage position next to the tail data of the file 1, and sequentially stores the tail data of the file in the ring buffer 20b.

In this way, the data of the empty area, the title information of the music, etc. are all removed, and the file 1,
Data of 2, ... Are continuously stored in the ring buffer 20b.

The computer 21 reads the data thus stored in the ring buffer 20b and reproduces the data. This processing will be described based on the flowchart shown in FIG.

The computer 21 uses the ring buffer 20.
The data of the file is extracted from b and output to the decoder 18 (step S31).

The computer 21 uses the ring buffer 20b.
It is determined whether or not there is data to be reproduced (step S32). When it is determined that there is data to be reproduced in the ring buffer 20b (Yes in step S32)
s), the computer 21 executes the process of step S31 again.

When it is determined that there is no data to be reproduced in the ring buffer 20b (N in step S32)
o), the computer 21 erases the reproduced data from the ring buffer 20b, and terminates the reproducing process.

When the data from the ring buffer 20b is read and output to the decoder 18 in this way, the decoder 18 decodes the music data, and the music data is continuously reproduced without a silent state.

As described above, according to the present embodiment, the computer 21 determines the music data and the empty data of the file based on the detected start tag and end tag, and extracts only the music data. It is stored in the ring buffer 20b and reproduced.

Therefore, even if the optical disc 1 is a CD-ROM in which music data compressed in frame units is recorded, it is possible to remove the empty area from the decompressed data and eliminate any silent state. It can be omitted.
Therefore, when the songs are continuous, such as the live version, a normal music CD, a CD-DA (Compact Disk Digital Au), is used.
dio) can be continuously played music data in the same way.

Various modes are conceivable for carrying out the present invention, and the present invention is not limited to the above modes. For example, the optical disc is not limited to the CD-ROM, but may be MD (MD: Mini Disc-trademark), DV.
D (Digital Versatile Disk), CD-R (Compact Di
sk Recordable), CD-RW (Compact Disk ReWritab)
le) or the like. Further, the recording medium is not limited to the optical disc, and for example, MP3 (MPEG Audio
It may be a semiconductor memory such as Layer-3).

In this embodiment, the buffer and the ring buffer are provided in the same memory. However, they can be provided separately.

In order to discriminate the file data, a dedicated file system (program) can be used. It is also possible to determine whether the data is music data or empty area data based on the result of decoding the data stored in the buffer by the decoder. By doing this, it is possible to determine the music data even if the tag information is not included.

[0076]

As described above, according to the present invention,
Data can be continuously reproduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical disc device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining each area provided on the optical disc.

FIG. 3 is a flowchart showing a data reading process from an optical disc, which is executed by the computer of FIG.

FIG. 4 is an explanatory diagram for explaining the operation of FIG.

5 is a flowchart showing a data fetching process from a buffer executed by the computer of FIG.

6 is a flowchart showing a read (reproduction) process from a ring buffer executed by the computer of FIG.

[Explanation of symbols]

1 optical disc 14 Servo circuit 21 computer 20 memory 20a buffer 20b ring buffer

Claims (6)

[Claims] 1. A reproducing apparatus for reproducing music data compressed and recorded in a recording medium in frame units, wherein the compressed data recorded in the recording medium is expanded in frame units and the expanded data is stored. Decompressed data storage means for determining whether the data stored in the decompressed data storage means is music data or empty data compressed together with the music data on a frame-by-frame basis. A reproducing apparatus comprising: song data extracting means for extracting only the song data; and data reproducing means for reproducing the song data extracted by the song data extracting means. 2. The song data extracting means analyzes the data stored in the decompressed data storage means to identify a leading identifier for identifying the leading data of the song data and an ending identifier for identifying the ending data of the song. However, if the data recorded at the recording position between the head identifier and the tail identifier is music data, and the data recorded at the recording position between the tail identifier and the head identifier is null data. The reproducing apparatus according to claim 1, wherein the reproducing apparatus is configured to determine and to extract only the determined song data. 3. The music piece data extracting means is provided with music piece data storage means for storing the music piece data extracted from the decompressed data storage means and reading it out continuously when reproducing. The playback device according to claim 1 or 2. 4. The recording medium is an optical disc, and reproduces song data that is compressed and recorded in frame units on the optical disc. The reproducing device according to the item. 5. The recording medium is a semiconductor recording medium composed of a semiconductor, and reproduces music data recorded in the semiconductor recording medium compressed in frame units. The playback device according to claim 1. 6. A step of decompressing compressed data recorded on a recording medium in units of frames and storing the decompressed data, analyzing the stored data, and based on the analysis result,
A step of determining whether the stored data is song data or empty data compressed together with the song data in frame units, and extracting only the song data based on the determination result; and the extracted song data And a step of reproducing the.