JP2004078787A - In-vehicle audio equipment and data transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable data transfer from a medium to a hard disk at high speed without using an LSI and DSP dedicated to compression or a CPU of high performance and to enable the recording of data without compressing a capacity of the hard disk. <P>SOLUTION: Data of a medium 1 are read at high double speed and are transferred in a format as it is to the hard disk 3 without compressing and the data transferred to the hard disk 3 are read to a buffer memory 5 and compressed when the CPU 6 has a low load subsequently. Thus, even if the CPU 6 is not of high performance, the data transfer to the hard disk 3 is enabled at high speed without receiving a heavy load by a compression processing and the amount of data recorded in the hard disk 3 can be reduced by the subsequent compression processing. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an in-vehicle audio device and a data transfer method, and more particularly to an in-vehicle audio device having a hard disk and a method of transferring data from various media to a hard disk.
[0002]
[Prior art]
In recent years, the development of hard disks that can sufficiently withstand the vibration of vehicles has progressed, and in-vehicle audio devices equipped with hard disks have been provided. According to this kind of in-vehicle audio device, by reading data from various media such as a CD (Compact Disc), a DVD (Digital Video Disc), and an MD (Mini Disc) and transferring the data to a hard disk, a plurality of media can be read. Data can be recorded on the hard disk, and many music and videos can be viewed without removing and inserting media.
[0003]
[Problems to be solved by the invention]
As described above, in the in-vehicle audio device equipped with a hard disk, a desired song can be selected from a large number of song data of a plurality of CDs (for example, six or ten) as in a conventional CD changer. Has become a great attraction for users. Therefore, there is a desire of the user to complete the recording of data from the medium to the hard disk as quickly as possible.
[0004]
If attention is paid only to reading data from a CD, data can be read in a short time by using a CD drive compatible with high speed. Therefore, if data is transferred to the hard disk in the format recorded on the medium, this can be performed at high speed. However, most of the music data recorded on the CD is uncompressed PCM data and the like, and has a large data size, so that it is compressed and recorded on the hard disk. In addition, even when already compressed data is transferred to a hard disk and recorded, the compression format may be converted.
[0005]
Regarding compression processing or compression format conversion processing, conventional on-vehicle audio devices often perform real-time processing using a dedicated LSI or DSP (Digital Signal Processor) or the like. If these LSIs or DSPs are used, the transfer recording of data to the hard disk and the real-time processing of compression or compression format conversion can be performed at relatively high speed. However, this required expensive LSIs and DSPs.
[0006]
On the other hand, it is practically possible for the CPU that controls the entire system to execute the compression processing or the compression format conversion processing without using a dedicated LSI or DSP. However, such a method does not require dedicated components, but requires a high-performance CPU. In other words, even if a CPU that does not have sufficiently high performance performs compression processing or compression format conversion processing in real time, the processing load is large, so that real-time processing is difficult, and furthermore, there is a delay to other processing executed by the CPU. There was a risk of causing the problem described above.
[0007]
The present invention has been made in order to solve such a problem, and an LSI or DSP dedicated to compression processing or compression format conversion processing, or other CPUs without using a high-performance CPU or the like can be used. High-speed data transfer from the media to the hard disk can be performed without affecting the processing, and data can be recorded without compressing the hard disk capacity by performing compression processing or compression format conversion processing. The purpose is to be able to.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, after reading data of a medium at a high speed higher than 1 × speed and storing the data in a buffer unit, the data stored in the buffer unit is reproduced at a 1 × speed, and Is transferred to the hard disk at a high speed higher than 1 × speed without compression, and the data transferred to the hard disk is subjected to compression processing or compression format conversion processing at a low load when the transfer processing is not performed thereafter. Like that. The transfer process to the hard disk in this case uses, for example, a time difference between the time for reading the data of the medium at a high speed and storing it in the buffer means and the time for reproducing the data stored in the buffer means at the normal speed. Do it.
[0009]
According to the present invention configured as described above, first, the data on the medium is read at a high speed, sent to the buffer means and stored. Using this buffer means, the media data is reproduced at 1 × speed, and in the background, the media data is transferred to the hard disk at high speed in the same format without undergoing compression processing or compression format conversion processing. Is recorded. For example, when transferring music CD data for 60 minutes to a hard disk using an 8 × -speed CD drive, the transfer is completed in about 7 minutes and 30 seconds. Thereafter, no data is read from the medium, so that the medium can be taken out from the on-vehicle audio device.
[0010]
Next, compression processing or compression format conversion processing of the data transferred to the hard disk is performed at a low load when the transfer processing is not performed, for example, during a period when the CPU usage rate is low. For example, data of a medium is read from a hard disk every predetermined time, compression processing or compression format conversion processing is performed, and data after the processing is re-recorded on the hard disk.
[0011]
As described above, by clearly dividing the data transfer period from the medium to the hard disk and the compression or format conversion period of the data recorded on the hard disk into two stages and processing the data in two stages, a burden is imposed on a time-consuming compression process. And data can be transferred to the hard disk at high speed. Further, it is possible to fill a gap in the processing time between the relatively high-speed data read processing from the medium and the relatively low-speed compression processing or compression format conversion processing. Therefore, it is possible to shorten the time required for transferring media data to the hard disk, and to reduce the amount of data to be recorded on the hard disk by a subsequent compression process. Data can also be recorded.
[0012]
According to another aspect of the present invention, when data of a medium is transferred to a hard disk, index information for specifying data that has been transferred is recorded, and when the medium is inserted into an in-vehicle audio device, the index information is recorded. The transferred data is grasped based on the index information, and only the data that has not been transferred is transferred to the hard disk.
[0013]
According to the present invention configured as described above, even if the media is removed from the in-vehicle audio device during the transfer, for example, even if the media data is transferred to the hard disk at a high speed, When the medium is inserted into the HDD, data that has already been transferred is not transferred, and only data that has not been transferred is transferred to the hard disk and recorded. As a result, it is possible to eliminate the waste of transferring the same data to the hard disk in duplicate. Further, even when the medium is reproduced intermittently for a relatively short time, all data on the medium can be transferred to the hard disk for recording.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration example of the vehicle-mounted audio device according to the present embodiment. In FIG. 1, reference numeral 1 denotes a medium (recording medium) such as a CD, a DVD, and an MD, which stores data such as music and video. Reference numeral 2 denotes a media drive, which controls reading of data from the medium 1. The media drive 2 has a function of reading data at a high speed and constitutes a reading unit of the present invention.
[0015]
Reference numeral 3 denotes a hard disk which records various data. In the present embodiment, a case where data of the medium 1 is transferred to and recorded on the hard disk 3 will be described. Reference numeral 4 denotes an interface unit that reads and writes data, and is configured by, for example, an ATAPI (AT Attachment Packet Interface). The ATAPI is an interface for connecting peripheral devices (such as the media drive 2) other than the hard disk 3 to an IDE (Intelligent Drive Electronics) interface (not shown) of the hard disk 3, and realizes data transfer with a high operating frequency. Is possible.
[0016]
Reference numeral 5 denotes a buffer memory for temporarily storing data of the medium 1 read by the media drive 2. The buffer memory 5 includes a first area used for reproducing data of the medium 1 at 1 × speed, and a second area used for transferring data of the medium 1 to the hard disk 3 at high speed. In. The structure will be described in detail with reference to FIG. This buffer memory 5 corresponds to the buffer means of the present invention.
[0017]
Reference numeral 6 denotes a CPU, which controls the entire on-vehicle audio device. In this embodiment, in particular, processing of reading data of the medium 1 at a high speed by the media drive 2 and storing the read data in the buffer memory 5 and reading of data of the medium 1 at a high speed by the medium drive 2 and reading of the read data Is transferred to the hard disk 3 via the buffer memory 5. The CPU 6 together with the media drive 2 and the interface unit 4 constitute transfer means of the present invention.
[0018]
In the present embodiment, the process of storing the data of the medium 1 in the buffer memory 5 is performed at a high speed, while the process of reproducing the data from the buffer memory 5 is performed at a speed of 1 as described later. Therefore, there is a difference between the time required to store the data of the medium 1 in the buffer memory 5 and the time required to reproduce the data stored in the buffer memory 5. In other words, after the data of the medium 1 is stored in the buffer memory 5 at a high speed and before all the data is reproduced at a 1 × speed, the idle time during which the data is not transferred from the medium 1 to the buffer memory 5 is available. Occurs. The CPU 6 executes a process of transferring the data of the medium 1 to the hard disk 3 at a high speed using the idle time.
[0019]
Further, after transferring the data from the medium 1 to the hard disk 3, the CPU 6 reads the transferred data from the hard disk 3 to the buffer memory 5, compresses the data, and stores the compression result in the hard disk 3 again. Note that the target of the compression processing here is uncompressed PCM data or the like recorded on a CD. In the case of data that has already been compressed in a predetermined format, such as MD or DVD, conversion of the compression format is performed. Thus, the CPU 6 also constitutes the compression means of the present invention.
[0020]
Reference numeral 7 denotes an audio LSI which reproduces the audio data of the medium 1 stored in the buffer memory 5 at a normal speed. Reference numeral 8 denotes a D / A converter, which converts digital audio data reproduced by the audio LSI 7 into an analog signal. Reference numeral 9 denotes an amplifier, which amplifies the analog audio signal output from the D / A converter 8 to a predetermined level. Reference numeral 10 denotes a speaker, which outputs reproduced sound based on the amplified analog audio signal. The audio LSI 7, the D / A converter 8, the amplifier 9, and the speaker 10 constitute a reproducing unit of the present invention.
[0021]
Reference numeral 11 denotes a video LSI, which reproduces video data of the medium 1 stored in the buffer memory 5 at a normal speed. Reference numeral 12 denotes a display, which displays a reproduced video based on the digital video data reproduced by the video LSI 11. The video LSI 11 and the display 12 also constitute playback means of the present invention.
[0022]
FIG. 2 is a diagram for explaining an operation related to data transfer of the vehicle-mounted audio device configured as described above. Here, a case where a CD or the like on which music data is recorded is used as an example of the medium 1 will be described. As shown in FIG. 2, the buffer memory 5 includes a first area 21 used for reproducing the music data read from the medium 1 at 1 × speed by the audio LSI 7 and a music data read from the medium 1 at a high speed. And a second area 22 used for transfer to the hard disk 3.
[0023]
Both the first and second areas 21 and 22 have a so-called double buffer structure, and data is read and written alternately in two storage areas (represented by A and B in the figure). . That is, when data is being read from one area A, the next data is written to the other area B. Thereafter, when the data reading from one area A is completed, the read / write areas are exchanged, the data written so far in the other area B is read continuously, and the next data is written in the one area A. Write. For example, by repeatedly performing such processing in the first area 21, the reproduction processing can be executed by the audio LSI 7 without interrupting the sound.
[0024]
In the example of FIG. 2, it is assumed that the user has designated to start reproduction from the third music piece of the medium 1. When the media 1 is inserted into the in-vehicle audio device and the number of the music to be reproduced is specified as necessary, the data for a predetermined time (for x seconds) from the beginning of the specified reproduction target section is output by the media drive 2. Read at double speed. Then, the read data is sent to the buffer memory 5 via the interface unit 4 and stored in one area A of the first area 21.
[0025]
When data is stored in one area A of the first area 21, it is reproduced by the audio LSI 7 at 1 × speed. As described above, the time for storing data for a predetermined time in this area A is shorter than the time for reproducing data for a predetermined time stored in one area A of the first area 21. For example, when data for 20 seconds is stored in the buffer memory 5 at a quadruple speed, the reproduction from the buffer memory 5 takes 20 seconds, whereas the storage in the buffer memory 5 takes only 5 seconds. Therefore, until the reproduction of the data stored in the area A is completed, a free time of 15 seconds occurs in which the data transfer from the medium 1 to the buffer memory 5 is not performed.
[0026]
The CPU 6 executes a process of transferring the data of the medium 1 to the hard disk 3 at a high speed using the idle time. That is, when data for a predetermined time is stored in one area A of the first area 21 as described above, the data of the medium 1 is read from the beginning of the first music by the media drive 2 simultaneously with the reproduction of the data. Read at high speed. Then, the read data is sent to the buffer memory 5 via the interface unit 4 and stored in one area A of the second area 22. The data stored in this area is transferred to the hard disk 3 in the same data format.
[0027]
Here, the process of storing data from the medium 1 to the second area 22 of the buffer memory 5 is performed at a high speed, and the process of transferring data from the buffer memory 5 to the hard disk 3 is also performed at a high speed by the interface unit 4. Be done. Therefore, it is possible to transfer more data than 15 seconds from the medium 1 to the hard disk 3 during the idle time of 15 seconds in the above example.
[0028]
Next, the reproduction of the data stored in one area A of the first area 21 proceeds, and when the remaining reproducible time decreases to a predetermined value, data for the next predetermined time from the medium 1 is transmitted by the media drive 2. Read at high speed. Then, the read data is sent to the buffer memory 5 via the interface unit 4 and stored in the other area B of the first area 21. Thereafter, when the reproduction of the data stored in one area A of the first area 21 is completed, the data stored in the other area B in the background during the reproduction is continuously reproduced at 1 × speed by the audio LSI 7. Is done.
[0029]
At the same time as the reproduction, the data transfer from the medium 1 to the hard disk 3 is performed by using the free time generated by the difference between the data storage time in the area B and the reproduction time again. That is, the next data is read from the medium 1 by the medium drive 2 at a high speed. Then, the read data is sent to the buffer memory 5 via the interface unit 4 and stored in the other area B of the second area 22. The data stored in the area B is transferred to the hard disk 3 in the same data format.
[0030]
Thereafter, by repeatedly performing such processing, the data is transferred to the hard disk 3 at a high speed while the data of the medium 1 is reproduced at 1 × speed.
In this example, data transfer from the medium 1 to the hard disk 3 is performed via the buffer memory 5, but this is in accordance with the standard of the interface unit 4.
[0031]
FIG. 3 is a flowchart showing the overall operation of the in-vehicle audio device according to the present embodiment. In FIG. 3, the CPU 6 determines whether or not the medium 1 has been inserted into the in-vehicle audio device (step S1). When the medium 1 is inserted, the data of the reproduction target portion is read from the medium 1 for a predetermined time (for x seconds) by the media drive 2 at a high speed, and the first area 21 of the buffer memory 5 via the interface unit 4. (Step S2).
[0032]
When the data is stored in the first area 21, the audio LSI 7 or the video LSI 11 starts reproducing the data at 1 × speed (step S3). Next, the CPU 6 determines whether or not TOC (Table of Contents) information corresponding to the currently inserted medium 1 is recorded on the hard disk 3 (step S4). The TOC information is index information indicating the position of data recorded on the hard disk 3 and the like, and information for specifying the medium 1 itself and information for specifying the data of the medium 1 (such as music data of each track). including.
[0033]
If the TOC information corresponding to the medium 1 is not recorded on the hard disk 3, it means that the data of the medium 1 has not been transferred to the hard disk 3 yet. In this case, the CPU 6 designates the head of the medium 1 as an area where the data transfer starts (step S5).
[0034]
On the other hand, if the TOC information corresponding to the medium 1 is recorded on the hard disk 3, it means that the medium 1 has been inserted before and at least a part of the data has been transferred to the hard disk 3. In this case, the CPU 6 grasps the transferred data on the basis of the TOC information, and designates a continuation area in which the data whose transfer has not been completed exists (step S6). If all the data of the inserted medium 1 has been transferred, the transfer start area is not specified, and the data transfer is not executed in the subsequent processing.
[0035]
When the data transfer start area is specified in step S5 or step S6, the media drive 2 reads data for a predetermined time (y seconds: y = x) from the specified area at a high speed. . After temporarily storing the read data in the second area 22 of the buffer memory 5 via the interface unit 4, the CPU 6 transfers the read data to the hard disk 3 via the interface unit 4 (step S7).
[0036]
Next, the CPU 6 determines whether or not all the data of the medium 1 has been transferred to the hard disk 3 (step S8). If all the data has not been transferred yet, it is further determined whether or not an operation for removing the medium 1 from the in-vehicle audio device has been performed (step S9). If the medium 1 has not been removed, it is further determined whether or not the remaining reproduction time of the data stored in the first area 21 of the buffer memory 5 has decreased to a predetermined value in step S2 (step S10).
[0037]
Here, if the remaining reproduction time is still larger than the predetermined value, the process returns to step S7, and the data of the next predetermined time (y seconds) is further read by the media drive 2 at a high speed, and the second data in the buffer memory 5 is stored. The data is transferred to the hard disk 3 via the area 22. If the remaining reproduction time has decreased to the predetermined value, the data transfer from the medium 1 to the hard disk 3 is temporarily stopped (step S11). Then, data for the next predetermined time (for x seconds) relating to the reproduction target portion is read from the medium 1 at a high speed and stored in the first area 21 of the buffer memory 5 (step S12).
[0038]
The data stored in the first area 21 of the buffer memory 5 in step S12 is reproduced at 1 × speed by the audio LSI 7 or the video LSI 11 after the reproduction of the previously stored data for x seconds is completed. You. After the data of the reproduction target portion is newly stored in the first area 21 of the buffer memory 5, the process returns to step S7, and the data for the next predetermined time (y seconds) is further read from the medium 1 at a high speed. The data is transferred to the hard disk 3 via the second area 22 of the buffer memory 5.
[0039]
When the operation for removing the medium 1 from the in-vehicle audio device is performed in the course of performing the loop processing of steps S7 to S12, the audio LSI 7 and the video LSI 11 stop the reproduction processing (step S13). Further, the CPU 6 generates TOC information indicating the data transferred to the hard disk 3 until the medium 1 is removed, records the TOC information on the hard disk 3 (step S14), and ends the process. Although the TOC information is recorded on the hard disk 3 here, a non-volatile memory (not shown) may be prepared separately from the hard disk 3 and recorded here.
[0040]
When all the data of the medium 1 has been transferred to the hard disk 3 by performing the loop processing of steps S7 to S12, the CPU 6 generates TOC information indicating the transferred data and records it on the hard disk 3 ( Step S15). Thereafter, the data transferred to the hard disk 3 is read out to the buffer memory 5 and subjected to a compression process or a compression format conversion process (step S16). The processed data is stored again in the hard disk 3 and the process is terminated.
[0041]
The compression processing or the compression format conversion processing in step S16 is performed when the processing capacity of the CPU 6 is sufficient. For example, when watching the media 1 already transferred to the hard disk 3 or listening to the radio, there is no need to transfer data from the media 1 to the hard disk 3, and the CPU 6 has sufficient processing capacity. is there. Therefore, it is possible to perform compression processing or compression format conversion processing during this time.
[0042]
In step S10, it is determined whether the remaining reproduction time of the previously stored data has decreased to a predetermined value. However, it may be determined whether the reproduction time has reached a predetermined value. . Further, the criterion is not limited to time, and the remaining playable amount may be determined based on, for example, the data amount.
[0043]
In steps S1 and S9, the removal and insertion of the medium 1 is detected. However, an operation of stopping the reproduction with the medium 1 inserted may be performed. Therefore, in steps S1 and S9, a similar branching process may be performed by detecting the start and end of reproduction.
[0044]
As described above in detail, according to the present embodiment, music and video are reproduced at 1 × speed, and the data of the medium 1 is read at high speed and transferred to the hard disk 3 in the background. . At this time, the data of the medium 1 is transferred to the hard disk 3 in the same format without being compressed, and thereafter, the data transferred to the hard disk 3 is subjected to compression processing or compression format conversion processing.
[0045]
In this way, when data is transferred, the raw data is transferred as it is, so that the data transfer can be performed in real time at a high speed even with the CPU 6 which is not so high-performance generally used in the in-vehicle audio device. Thus, the time until the data of the medium 1 is completely transferred to the hard disk 3 can be shortened. This makes it possible to transfer all the data of the medium 1 to the hard disk 3 without having to wait until the entire medium 1 is reproduced.
[0046]
Further, by performing the compression processing or the compression format conversion processing after the data transfer is completed, the data amount to be recorded on the hard disk 3 can be reduced, and more data can be recorded. It should be noted that even if the margin of the CPU power in performing the compression process or the compression format conversion process is not sufficient, and even if the compression process or the compression format conversion process takes a certain amount of time, the data transfer is not performed at that time. Since there is no interruption in the reproduced sound, there is no particular problem.
[0047]
Further, according to the present embodiment, TOC information indicating data that has been transferred from the medium 1 to the hard disk 3 is recorded on the hard disk 3. Then, for example, when the medium 1 is removed from the in-vehicle audio device before the transfer of all data from the medium 1 to the hard disk 3 is completed, and then the same medium 1 is inserted again, only the data whose transfer has not been completed is deleted. The data is transferred to the hard disk 3.
[0048]
As a result, it is possible to eliminate the waste of transferring data already transferred to the hard disk 3 redundantly. Further, even when the medium 1 is reproduced intermittently for a relatively short time, all data on the medium 1 can be transferred to the hard disk 3 and recorded. Therefore, it is possible to transfer all the data of the medium 1 to the hard disk 3 while performing the short distance driving several times.
[0049]
In the above embodiment, after the data of the medium 1 is stored in the buffer memory 5 in units of x seconds, the data of x seconds stored in the buffer memory 5 is played back while using the free time while reproducing the data of x seconds. Although the first data is transferred to the hard disk 3, the present invention is not limited to this example. For example, all the data of the medium 1 is stored in the buffer memory 5 first, and thereafter, while the data stored in the buffer memory 5 is reproduced at 1 × speed, the data is transferred to the hard disk 3 in the background. You may do it.
[0050]
In this way, data can be transferred to the hard disk 3 using the data stored in the buffer memory 5. As a result, even if the medium 1 is removed from the in-vehicle audio device during playback, data transfer from the buffer memory 5 to the hard disk 3 can be continued, and the data transfer of the medium 1 can be completed.
[0051]
Further, in the above-described embodiment, an example in which the data transfer method of the present invention is applied to an in-vehicle audio device has been described. However, the applied audio device is not limited to the in-vehicle audio device. Further, the present invention is not limited to the audio device, and can be applied to any electronic device having a purpose of transferring data from the medium 1 to the hard disk 3.
[0052]
In the above-described embodiment, an example has been described in which data is transferred to the hard disk 3 in the background while the data of the medium 1 is reproduced. However, only the data transfer to the hard disk 3 is performed without reproducing the data of the medium 1. It goes without saying that it is possible.
[0053]
In addition, the above-described embodiment is merely an example of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted in a limited manner. That is, the present invention can be embodied in various forms without departing from the spirit or main features thereof.
[0054]
【The invention's effect】
As described above, according to the present invention, after reading data from a medium at a high speed and storing the data in a buffer, the data stored in the buffer is transferred to a hard disk at a high speed while reproducing the data stored at a 1 × speed. At the same time, after transferring the data of the medium to the hard disk, the data transferred to the hard disk is subjected to a compression process or a compression format conversion process at a low load when the transfer process is not performed. As a result, even without using a dedicated LSI or DSP for compression processing or compression format conversion processing, or a high-performance CPU, it is possible to transfer and record data from the medium to the hard disk without affecting other processing of the CPU. Can be performed at high speed, and the time until the transfer of media data to the hard disk is completed can be shortened. Further, the amount of data to be recorded on the hard disk can be reduced by the subsequent compression processing or compression format conversion processing, and data can be recorded without squeezing the limited capacity of the hard disk.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of an in-vehicle audio device according to an embodiment.
FIG. 2 is a diagram for explaining an operation related to data transfer of the in-vehicle audio device according to the present embodiment.
FIG. 3 is a flowchart showing an overall operation of the on-vehicle audio device according to the embodiment;
[Explanation of symbols]
1 Media
2 Media drive
3 Hard disk
4 Interface section
5 Buffer memory
6 CPU
7 Audio LSI
8 D / A converter
9 Amplifying unit
10 Speaker
11 Video LSI
12 Display
21 First area for data playback
22 Second area for data transfer

Claims (5)

For in-vehicle audio equipment equipped with a hard disk,
Reading means for reading media data at a high speed higher than 1 × speed;
Buffer means for temporarily storing data of the medium read by the reading means,
Reproducing means for reproducing the data stored in the buffer means at 1 × speed;
Utilizing a time difference between a time for reading the data of the medium at a high speed by the reading means and storing the data in the buffer means and a time for reproducing the data stored in the buffer means at a normal speed by the reproducing means. Transfer means for reading data of the medium at a high speed higher than 1 × speed and transferring the data to the hard disk;
Compression means for performing compression processing or compression format conversion processing on data transferred from the medium to the hard disk by the transfer means at a low load when the transfer processing by the transfer means is not performed. Features on-board audio equipment. When the data of the medium is transferred to the hard disk by the transfer means, index information for specifying the transferred data is recorded, and the transferred data is grasped from the index information and transferred. 2. The in-vehicle audio device according to claim 1, further comprising a transfer management unit that manages the transfer unit to transfer only the data that has not been completed to the hard disk. A data transfer method for transferring media data to a hard disk,
After reading the data of the medium at a high speed higher than 1 × speed and storing it in the buffer means,
While reproducing the data stored in the buffer means at 1 × speed, the data of the medium is transferred to the hard disk at a high speed higher than 1 × speed without compression,
A data transfer method, wherein the data transferred to the hard disk is subjected to a compression process or a compression format conversion process at a low load when the transfer process is not performed thereafter. The transfer of the data of the medium to the hard disk is performed by reading the difference between the time for reading the data on the medium at a high speed and storing the data in the buffer means and the time for reproducing the data stored in the buffer means at a normal speed. 4. The data transfer method according to claim 3, wherein the transfer is performed using time. When transferring the data of the medium to the hard disk, index information for specifying the transferred data is recorded, and the transfer is performed before the transfer of all the data in the medium is completed. 4. The system according to claim 3, wherein when the transfer is stopped and the transfer is resumed thereafter, the transferred data is grasped from the index information, and only the data whose transfer has not been completed is transferred to the hard disk. Data transfer method described.

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