JP3871831B2 - Playback device and playback method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reproducing apparatus such as a CD player, a CD-ROM apparatus, a CD-R apparatus, and a CD-RW apparatus for reproducing music data on a CD-ROM and a reproducing method thereof.
[0002]
[Prior art]
The CD standards originating from the music CD standards are very complicated in various ways such as recording formats and media types, but can be broadly divided into music applications and computer applications.
[0003]
A playback device called a CD player is mainly used in the former application, and a playback device called a CD-ROM drive is used in the latter application. Usually, both devices have a playback function of a CD-DA disc.
[0004]
However, there is no function for reproducing music data recorded as computer data, and music data is generally reproduced on a sound source board of a host computer.
[0005]
Conventionally, music data recording / reproduction and compression / decompression techniques (see, for example, Japanese Patent Laid-Open No. 9-185868) in the CD-ROM format have been proposed, but it is the most important for sharing data with a computer. It is not structured to interpret and play back file systems.
[0006]
Further explanation will be given. The CD-DA standard for music reproduction is defined by the Red Book (RED BOOK), and the CD-ROM standard for computer data storage is defined by the Yellow Book (YELLOW BOOK).
[0007]
The CD-ROM standard incorporates a sector structure that enables random access based on the CD-DA standard and a powerful error correction function.
[0008]
However, sequential read is the main and DA is a data format that is difficult for computers to handle because of rough random access and an error rate that is not sufficient for computer data.
[0009]
Generally, a CD is called multimedia. It is possible to handle a variety of information such as text, music, and video on a single medium due to the moderate storage capacity of CDs, the ease of copying, and the progress of established standards and data compression technology. This is because information is recorded as digital data that can be easily used by a computer.
[0010]
Currently, the performance of a personal computer is sufficient to handle multimedia, and even a basic personal computer can perform music composition, editing, mixing, and effects on a single machine. It ’s easy.
[0011]
In addition, since recordable CD drives have become cheaper, recording music data of songs created by them on a CD-R and listening to them with a CD player is also popular.
[0012]
By the way, in order to listen to music data created by a computer with a general CD player, it is necessary to create a CD in the CD-DA format.
However, since the CD-DA format is not suitable for storing computer data, music data is usually stored separately in a CD-ROM format or another storage device.
[0013]
[Problems to be solved by the invention]
However, if the music data is separately stored in the CD-ROM format or other storage device as described above, the CD-DA data is 16-bit stereo data sampled at 44.1 KHZ, and it takes about 1 minute. Since the amount of data is as large as 10 MB, there is a problem that it is very unreasonable to handle playback and storage separately.
[0014]
Next, there is a WAVE file as a music file that is typically handled by a typical OS of a personal computer.
A WAVE file has a simple structure in which information headers such as the number of channels, sampling rate, and number of quantization bits are added to PCM data, and CD-DA data converted into a WAVE file is easy with a D / A converter. Can be replayed.
[0015]
No special processing is required to play back this type of file, but as mentioned above, a WAVE file has a data amount of about 10 MB per minute, and the CD-ROM format can record data only for about 65 minutes. There are also disadvantages.
[0016]
Currently, data compression is indispensable for music distribution on networks such as the Internet. With the improvement in computer processing capability, various types of data can be compressed and decompressed by software, so that the motivation for storing or distributing music data as a file has increased greatly.
[0017]
For example, MP3 (MPEG1 AUDIO LAYER III), which is highly evaluated for its sound quality and compression ratio, can reduce the data to about 1/10 while maintaining the sound quality close to that of CD-DA. More than 150 songs can be stored .
[0018]
Next, the dramatic improvement in processing capability of personal computers in recent years seems to be well known, but the improvement in processing capability of embedded computer chips, ie, system controllers, is also the same.
[0019]
Conventionally, dedicated hardware was required for decompression of compressed data. However, decompression by software has become possible due to the improvement in processing capability of the system controller.
Also, considering a plurality of existing compression formats and a new compression format that will appear in the future, time and cost will increase if it is handled by hardware.
[0020]
Next, in order to reproduce a music file, it is necessary to know in advance where the music file is.
CD-DA can know the start position and time of a song by reading the TOC area on the disc. However, in the case of a CD-ROM music file, there is no such information and the file is searched. Must be obtained from directory information.
[0021]
However, file search takes time when the files are scattered in subdirectories or when the number of files is large, and the usability is impaired.
In addition, if a song name or album name is substituted with a file name or directory name, it is inconvenient because it causes a problem that it cannot be easily changed later.
[0022]
Accordingly, an object of the present invention is to improve the operability at the time of reproduction of a music file by reading a TOC file used for the configuration and management of the music file.
[0023]
Next, although the performance of the computer has improved, applications with high functionality and high load have also appeared at the same time.
[0024]
In general, a CD-ROM drive can reproduce a CD-DA, but cannot reproduce a music file regardless of whether or not it is compressed.
Reading a music file and transferring data to the sound source board by a computer is not a big deal in terms of processing, but the amount of data is large, so the CPU load increases considerably, and parallel operation with the application is performed. If this happens, the risk in terms of stability also increases.
[0025]
[Means for Solving the Problems]
In order to achieve the above object , the present invention searches for music files recorded on a recording medium including a subdirectory based on the extension of the file, and a music file search means for searching for music files. determination means for determining the file type based on the header of the music files, and converting processing means for predetermined processing depending on the type of file that is determined by the determining means, the music files to the music signal reproduction If the TOC file is found in the root directory, the music file is reproduced by the music reproducing means based on the TOC file, and the TOC file is found in the root directory. If not, the music file search means searches for the music file and the above Determining the file type of the searched music file by the disconnecting means, performing predetermined processing on the music file whose type is determined by the processing means, and reproducing the processed music file by the music reproducing means Provided is a playback apparatus.
[0026]
Further, in the reproducing apparatus as above SL, the determining means to means for determining the music file compression type, means for decompressing the music file on the basis of said processing means to the compression type is determined by the determining means It is good to.
[0027]
Further, in the reproducing apparatus as above SL, the means for the extension, may be provided to the system control means controls the whole of the reproducing apparatus.
[0028]
In addition, in the playback device, such as a top Symbol, and the above-mentioned TOC file, recording address of the music files that have been recorded on the recording medium, song time, and description file format, album name, song title, information such as artist name text A file should be used.
[0029]
Further, it may in the reproducing apparatus such as above SL, means for connecting the host computer, providing the means for executing the music reproducing means based on an instruction from the host computer connected by the means.
[0030]
Also, a directory on the recording medium in which the music file is recorded is read, and if there is a TOC file in the root directory, the music file recorded on the recording medium is converted into a music signal based on the TOC file and reproduced. If there is no TOC file in the root directory, the music file recorded on the recording medium is searched including the subdirectory based on the extension of the file, and the file is searched based on the header of the searched music file. A playback method is also provided in which the type is determined, a predetermined process is performed according to the determined file type, and the processed music file is converted into a music signal for playback.
[0031]
Further, in the reproduction method described above, the judgment determines the music file compression type, may extend the music file based on the type of compression the treatment is determined above.
[0032]
Furthermore, in the playback method as described above, the TOC file is a text describing information such as recording address, song time, file format, album name, song name, artist name, etc. of the music file recorded on the recording medium. in Then good file.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of an optical disk reproducing apparatus according to an embodiment of the present invention.
[0034]
In this optical disk reproducing apparatus, an optical disk 1 is rotationally driven by a spindle motor 2.
The spindle motor 2 is controlled by the motor driver 3 and the servo processing unit 4 so that the linear velocity or the angular velocity is constant. The linear velocity or angular velocity can be changed in stages.
[0035]
The pickup 5 includes a semiconductor laser light source, an optical system, a focus actuator, a track actuator, a light receiving element, and a position sensor (not shown), and has a function of reading data by irradiating the optical disk 1 with laser light.
[0036]
The pickup 5 can be moved in the sledge direction by a seek motor (not shown). The focus actuator, the track actuator, and the seek motor are controlled by the motor driver 3 and the servo processing unit 4 so that the laser spot is positioned at a target location based on signals obtained from the light receiving element and the position sensor.
[0037]
The reproduction signal obtained by the pickup 5 is amplified by the read amplifier 6 and binarized, and then input to the CD decoder 7 to undergo deinterleaving and error correction processing. At this time, the data that has not been fully error-corrected is complemented.
[0038]
In the case of CD-DA, the data is input to the D / A converter 8, amplified by the amplifier 14, and output to the line-out terminal 15 or the speaker 16 to reproduce music.
Further, the CD-ROM decoder 9 can be through-passed, and the data can be temporarily stored in the memory 10 and then input to the D / A converter 8, which is effective as a measure against sound interruption when the servo is released due to vibration.
[0039]
On the other hand, in the case of a CD-ROM, data is input to the CD-ROM decoder 9 and subjected to an error correction process for further improving the reliability of the data.
The system controller 17 controls whether the data is stored in the memory 10 as it is or whether it is stored in the memory 10 after the data expansion processing unit 11 performs the data expansion processing.
[0040]
The memory manager 12 controls data access to the memory 10 and can process data transfer to each unit in parallel. With this function, the data in the memory 10 can be sent to the D / A converter 8 or the host interface (I / F) 13 while reading the data from the optical disk 1 into the memory 10.
[0041]
The host interface 13 includes SCSI, ATAPI, USB, 1394, and the like, and connects a host computer.
The D / A converter 8 can adjust the conversion rate according to the sampling rate.
[0042]
The system controller 17 can control each of the above units, read out arbitrary sector data and store it in the memory 10, freely access the memory 10, analyze sector data, and decompress the data in the memory 10. It is also possible to perform processing and develop it in the memory 10.
[0043]
That is, the system controller 17 and the like respectively search for music files recorded on the recording medium including a subdirectory based on the file extension, and music searched by the music file search means. determination means for determining the file type based on the file header, music to be reproduced by converting processing means for predetermined processing according to the file type is determined by the determining means, the music files to the music signal Read the playback unit and the directory on the recording medium, and if there is a TOC file in the root directory, play the music file by the music playback unit based on the TOC file, and if there is no TOC file in the root directory, Detect music files by music file search means And determining the file type of the searched music file by the determining means, performing a predetermined process on the music file determined by the processing means, and processing the music file processed by the music reproducing means. The function of the means to reproduce .
[0044]
The functional means of determining the music file compression type as said determining means also play also serves means for expanding the music file based on compression type is determined by the determination means as the process means.
[0045]
In addition, the above-mentioned TOC file, recording address of the music files that have been recorded on the recording medium, song time, file format, there is a text file that describes the information such as the album name, song title, artist name.
[0046]
Furthermore, the function of means for connecting the host computer and means for executing the music reproducing means based on an instruction from the host computer connected by the means is achieved.
[0047]
The optical disk reproducing apparatus of this embodiment has a great feature in that it interprets a file system of an optical disk (for example, a CD-ROM), and a standard file system is ISO9660.
[0048]
FIG. 2 is an explanatory diagram showing the configuration of a file system based on ISO9660.
In ISO9660, a first volume descriptor (PRIMARY VOLUME DESCRIPTER: PVD) is placed in a sector having a logical block number (LOGICAL BLOCK NUMBER: LBN) 16.
[0049]
LBN is a method for addressing sectors on a medium such as an optical disk (addressed by a minute (MINUTE): second (SECOND): frame (FRAME) in a CD-ROM) with a sequential number, and is a CD-ROM. However, the present invention is not limited to this, and is also used for media such as HDD and MO.
[0050]
In the CD-ROM, it is defined that LBN = 0 starts from 00:02:00 (2 seconds 00).
LBN may be called a logical sector number (LOGICAL SECTER NUMBER: LSN) or a logical block address (LOGICAL BLOCK ADDRESS: LBA).
[0051]
In ISO9660, there are a method of searching for a target file position in order from a root directory indicated by PVD, and a method of pointing from a path table (PATH TABLE) at the same time.
[0052]
The method of following in order from the root directory is similar to the FAT file of MS-DOS. However, since many seeks are generated in the process of tracing, a large overhead is generally caused in a CD-ROM drive in which seek time is not so fast.
[0053]
Therefore, it is common to place pointers to all directories and files in the optical disk in a static area called a path table, and search directly from there. The location of the path table is also pointed from the PVD.
[0054]
The optical disc playback apparatus of this embodiment interprets the file structure in order to play back music files, and in the case of music data extracted and compressed data, decompression processing is necessary.
[0055]
A typical non-compressed music file is a WAVE file, and a typical compressed music file is an MPEG1 / AUDIO file. These structures are shown in FIGS.
[0056]
As shown in FIG. 3, the WAVE file has a structure in which a header of 44 bytes is arranged at the head of the music data.
In this header, the sampling rate, the number of quantization bits, and the music data size are recorded. If the D / A converter 8 is set based on this information, the music can be reproduced simply by sending the music data as it is. .
Generally, “WAV” is used as the file name extension of this file.
[0057]
On the other hand, the MPEG1 / AUDIO file is composed of a plurality of frames shown in FIG. 4 and 128-byte information called ID3 tags.
In the frame header, information necessary for decompression such as sampling rate and bit rate is recorded.
[0058]
In the case of an MPEG1 AUDIO LAYER III file, “MP3” is generally used as the file name extension.
If these file extensions are used, the existence of the file can be confirmed from the directory information.
The system controller 17 may execute the decompression process of the MPEG1 AUDIO LAYER III file.
[0059]
Furthermore, if the file name is the song name and the directory name is the album name, information that is not included in the table of contents information (TOC) of the CD-DA can be acquired.
However, only the music time important as the music information cannot be calculated from the file size unless the type of the music file is fixed, and cannot be known unless the file is read. In other words, searching for a large number of songs takes a very long time.
[0060]
Therefore, in the optical disc playback apparatus of this embodiment, the above-described search is made unnecessary by reading out a TOC file in which song information is compiled in advance.
This TOC file is a specific text file existing in the root directory, and its structure is shown in FIG.
[0061]
The contents of the TOC file are roughly divided into album information and track information, and numbers are assigned for each of them.
The configuration example of FIG. 5 shows a case where the album is composed of 3 tracks.
As album information, there are an album name, an artist name, and an attribute track, and a track number is designated for the attribute track.
[0062]
A plurality of track numbers can be specified by a hyphen “-” and a comma “,”. The track information includes a recording address, song time, file format type, song name, and artist name. Since the address is a logical address of the CD-ROM in which the music file is recorded, the music file can be directly accessed only by this TOC file.
[0063]
FIG. 6 is a flowchart showing the process of obtaining and playing back song information on the optical disc in this optical disc playback apparatus.
In this process, it is determined in step (indicated by “S” in the figure) 1 whether or not an optical disk has been inserted. If it is detected that an optical disk has been inserted, the process proceeds to step 2 to perform a mounting process. In this mounting process, the TOC area of the optical disk 1 is read to acquire the track mode and length (time). This mounting process makes it possible to determine whether the optical disk is a CD-DA or a CD-ROM.
[0064]
The process proceeds to step 3 to determine whether or not the optical disk is a CD-DA disk. If the optical disk is a CD-DA disk, the process proceeds to step 8 and waits for a reproduction command. Read and proceed to step 5 to determine whether a TOC file exists in the root directory.
[0065]
If it is determined in step 5 that there is no TOC file, the process proceeds to step 6 to search for music files including subdirectories based on the extension of the file name, and proceeds to step 7 to access the detected music file. Get song time.
If it is determined in step 5 that there is a TOC file, the process proceeds to step 10 where the TOC file is read to acquire music information, and the process proceeds to step 8.
[0066]
In step 8, it is determined whether or not there is a reproduction command. If there is a reproduction command, the process proceeds to step 9 to execute reproduction processing.
The reproduction command is based on a switch on the operation unit or a command from the host computer.
If there is a reproduction command, the reproduction-instructed music file is read out, the file type is determined, if it is a compressed file, it is decompressed as appropriate, the reproduction rate is set, and the data is transferred to the D / A converter 8. To play music files.
[0067]
In this way, the optical disk playback apparatus can play back music stored in the computer immediately without having to create two CDs for playback and storage because the music file can be played back as it is.
Also, since the compressed music file can record 100 songs or more and 600 minutes or more on one CD, it is very suitable for storing music, and the optical disc can be directly played back.
[0068]
In addition, the hardware cost for the decompression process can be reduced, and more decompression procedures can be handled in a short period of time.
Also, since song information can be acquired at high speed, album management and song name change can be facilitated.
Furthermore, information that is not available on the CD-DA, such as the song title and lyrics, can be associated with the song.
[0069]
The music file can be reproduced without imposing a load on the CPU of the host computer, and the host interface can be adapted to a recording / reproducing apparatus such as a CD-R drive.
[0070]
According to this optical disk reproducing apparatus, music data suitable for storage can be directly reproduced as it is by a computer.
Further, compressed music data suitable for storage on a computer can be directly reproduced as it is.
Furthermore, compressed music data suitable for storage by a computer can be reproduced in software using a system controller.
Furthermore, the music file can be directly reproduced by an instruction from the host computer.
[0071]
【The invention's effect】
As described above , according to the playback apparatus and playback method of the present invention, it is possible to improve the operability at the time of playback of a music file by reading the TOC file used for the configuration and management of the music file. it can.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an optical disk reproducing apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a configuration of a file system based on ISO9660 on an optical disc played back by the optical disc playback apparatus shown in FIG. 1;
FIG. 3 is an explanatory diagram showing a structure of a WAVE file on an optical disc played back by the optical disc playback apparatus shown in FIG. 1;
4 is an explanatory diagram showing a structure of an MPEG1 / AUDIO file on an optical disc played back by the optical disc playback apparatus shown in FIG. 1; FIG.
FIG. 5 is an explanatory diagram showing a configuration of a TOC file on an optical disc played back by the optical disc playback apparatus shown in FIG. 1;
6 is a flowchart showing processing for obtaining and playing back song information on an optical disc in the optical disc playback apparatus shown in FIG. 1;
[Explanation of symbols]
1: Optical disk 2: Spindle motor 3: Motor driver 4: Servo processing unit 5: Pickup 6: Read amplifier 7: CD decoder 8: D / A converter 9: CD-ROM decoder 10: Memory 11: Data decompression processing unit 12: Memory manager 13: Host interface (I / F)
14: Amplifier 15: Line-out terminal 16: Speaker 17: System controller L: Laser light

Claims (8)

Music file search means for searching music files recorded on a recording medium including subdirectories based on the file extension, and the file type based on the header of the music file searched by the music file search means comprising determining means for determining, and processing means for predetermined processing according to the file type that is determined by said determining means, and a music reproducing means for reproducing by converting the music files to the music signal,
If a directory on the recording medium is read and a TOC file exists in the root directory, the music file is reproduced by the music reproduction means based on the TOC file. If there is no TOC file in the root directory, the music file search means The music file is searched for by the determining means, the file type of the searched music file is determined by the determining means, the music file whose type is determined by the processing means is subjected to predetermined processing, and the music reproducing means is A playback apparatus for playing back a processed music file . The playback apparatus according to claim 1, wherein
It said determining means is a means for determining said music file compression type reproducing apparatus the processing means, characterized in that the means for extending said music file based on the compression type is determined by said determining means. The playback apparatus according to claim 2, wherein
A reproducing apparatus characterized in that the expanding means is provided in a system control means for controlling the entire reproducing apparatus. In the reproducing | regenerating apparatus as described in any one of Claims 1 thru | or 3,
The TOC file is a text file in which information such as a recording address, a song time, a file format, an album name, a song name, and an artist name of a music file recorded on the recording medium is described. In the reproducing | regenerating apparatus as described in any one of Claims 1 thru | or 4,
A playback apparatus comprising: means for connecting a host computer; and means for executing the music playback means based on an instruction from a host computer connected by the means. A directory on a recording medium in which a music file is recorded is read, and if there is a TOC file in the root directory, the music file recorded on the recording medium is converted into a music signal based on the TOC file and reproduced. If there is no TOC file in the root directory, the music file recorded on the recording medium is searched including the subdirectory based on the file extension, and the file type is determined based on the header of the searched music file. A playback method comprising: determining, performing a predetermined process according to the determined file type, converting the processed music file into a music signal, and playing the music signal . The playback method according to claim 6, wherein
Reproducing method wherein determination is the determination of the music file compression type, said process characterized by extending said music file based on the determined compression type. The reproduction method according to claim 6 or 7,
The TOC file is a text file in which information such as a recording address, a song time, a file format, an album name, a song name, and an artist name of a music file recorded on the recording medium is described.

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