JP3200852B2 - Information signal reproducing apparatus and information signal reproducing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information signal reproducing apparatus and an information signal reproducing method for reproducing an information signal from a recording medium, and particularly to an information signal suitable for application to, for example, an audio and / or video server system. The present invention relates to a reproducing apparatus and an information signal reproducing method.

2. Description of the Related Art An audio / video server system (hereinafter, referred to as an apparatus) that supplies a video signal and an audio signal to a plurality of terminal devices from one video / audio supply source disposed in a broadcasting station or the like.
AV server system) has been proposed. As a configuration of the AV server system, a configuration is proposed in which video and audio signals are stored in a media unit having a plurality of built-in disk devices, and the selected video and audio signals are distributed from the media unit to a terminal device. Have been.

By the way, in such an AV server system, it is necessary to continuously transmit a video signal to each terminal device. For this reason, the media unit of the AV server system reproduces video and audio signals from a disk-shaped recording medium in a disk device so that a video signal of a constant data amount can always be supplied to each terminal device.

Here, a disk device for reproducing video and audio signals from a disk-shaped recording medium will be described. Here, a case where a hard disk device is used as a disk device will be described.

The hard disk device is configured to rotate a hard disk, which is a disk-shaped magnetic recording medium, to record video and audio signals on the hard disk by a recording / reproducing head, and to reproduce the video and audio signals from the hard disk. At this time, since there is generally one recording / reproducing head, access to video and audio signals on the hard disk by this recording / reproducing head is performed sequentially.

Further, since the recording / reproducing head operates mechanically, when the access position of the recording / reproducing head is largely changed, that is,
At the time of so-called seek, the access time is longer than when a continuous position is accessed by the recording / reproducing head. In addition, even after the recording / reproducing head is moved, a certain time is required until the position where the selected video and audio signal is recorded reaches the position of the recording / reproducing head. This is called rotation waiting time.

Here, when it is necessary to always supply a fixed amount of video and audio signals to each terminal device, such as a disk device used in the above-described AV server system, the seek, rotation wait, and data output are performed. In consideration of the total access time including the total access time, the ability to continuously output video and audio signals is required.

Also, in the AV server system, data read from the hard disk is a video and audio signal, so that real-time properties are required. For example, if the playback video and audio signals of 128 [kByte] are not continuously supplied to one terminal device per second, the video is interrupted.
Therefore, in order to supply video and audio signals to 12 terminal devices without interruption, assuming that the number of transmission channels is 12, 128 [kByte] * 12 [channels] per second = 15
It is necessary to reproduce 36 [kByte] video and audio signals from the hard disk.

Also, since the hard disk drive operates mechanically,
Although it occurs infrequently, unexpected behavior may occur in some cases. For example, when accessing the video and audio signals by moving the head over a predetermined circumference of the hard disk, the position of the recording and reproducing head is shifted due to expansion and contraction due to the temperature of each member and mechanical errors, and the video and audio signals are May not be read correctly. In this case, the hard disk device corrects the position of the recording / reproducing head and accesses again. Normally, correct video and audio signals can be read while repeating this access operation.

However, when such an operation is performed, the rotation waiting time is particularly increased, and the access speed is reduced. For this reason, when the reproduction data is supplied to each channel, the predetermined amount of data that must be read within one second, more specifically, within 950 [milliseconds] in consideration of the overhead time in the control system, for example. For example, if the video and audio signal block is played in 1.3 seconds, the next video and audio signal block cannot be reproduced in time and the video and audio signals supplied to the terminal device are interrupted. is there.

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an information signal reproducing apparatus and an information signal reproducing method capable of supplying video signals to a plurality of channels without interruption. It is to be.

The present invention relates to an information signal reproducing device for outputting information data reproduced from a recording medium, wherein the information signal reproducing device is divided into a plurality of data blocks, and adjacent data blocks are divided and recorded on different disk-shaped recording media. A plurality of reproduction means for reproducing information data in a reproduction block unit consisting of a predetermined number of data blocks from a plurality of disk-shaped recording media, and for each data block of the same number as the number of reproduction means in the plurality of data blocks. Error-correction code reproduction means for reproducing the error-correction code data recorded on another disk-shaped recording medium from another disk-shaped recording medium, and reproduced by one of a plurality of reproduction means. When there is an error in the data of the data block, or when the data is reproduced by one of the plurality of reproducing means. Error correction means for restoring correct data to be reproduced by the certain reproduction means from the data reproduced by the other reproduction means and the error correction code data reproduced by the error correction code reproduction means, And the control means for controlling the operation of the error correction code reproducing means. The control means terminates the reproduction of the reproduction block of n number (n is a positive integer) by the certain reproducing means within a predetermined time. If not, the operation of the plurality of playback units is controlled so that the (n + 1) th playback block is played back by the certain playback unit without the playback of the (n + 1) th playback block by the certain playback unit.

The present invention also relates to an information signal reproducing apparatus for outputting information data reproduced from a recording medium, wherein the information signal reproducing apparatus is divided into a plurality of data blocks, and adjacent data blocks are divided and recorded on different disk-shaped recording media. A plurality of reproduction means for reproducing the information data being reproduced from a plurality of disk-shaped recording media in units of a reproduction block consisting of a predetermined number of data blocks, and data of the same number as the number of reproduction means in the plurality of data blocks Generated for each block,
An error correction code reproducing means for reproducing error correction code data recorded on another disk-shaped recording medium from another disk-shaped recording medium, and a data block reproduced by one of a plurality of reproducing means. When there is an error in the data, or when the data is not reproduced by one of the plurality of reproducing means, the correct data to be reproduced by one reproducing means is corrected by the error correction by the data reproduced by the other reproducing means. An error correction means for restoring from the error correction code data reproduced by the code reproduction means; and a control means for controlling the operation of the plurality of reproduction means and the error correction code reproduction means. When the reproduction process of the (n + 1) th (n is a positive integer) reproduction block by the means does not start at a predetermined timing, the reproduction operation is started. Without regeneration of the (n + 1) th reproduced block is performed by, n by the certain reproduction means
The operation of a plurality of playback units is controlled so that the + 2nd playback block is played back.

Further, in the information signal reproducing device according to the present invention, the information data is divided into a plurality of data blocks for each predetermined data amount and recorded on a plurality of disk-shaped recording media,
Each of the m-th (m = 1, 2, 3,...) Data blocks is reproduced by the m-th reproduction unit of the plurality of reproduction units.

The present invention is also an information signal reproducing method for outputting information data reproduced from a recording medium, wherein the information signal is divided into a plurality of data blocks, and adjacent data blocks are divided and recorded on different disk-shaped recording media. The information data is reproduced from a plurality of disc-shaped recording media in units of a reproduction block composed of a predetermined number of data blocks, and the same number of data blocks as the number of the plurality of disc-shaped recording media out of the plurality of data blocks. The error correction code data generated for each disk and recorded on another disk-shaped recording medium is reproduced from another disk-shaped recording medium, and the data reproduced from one of the plurality of disk-shaped recording media is reproduced. When there is an error in the data of the block or when data is read from a certain disk-shaped recording medium among a plurality of disk-shaped recording media. When the data is not played, to restore the correct data to be reproduced from the certain disk-shaped recording medium, and a error correction code data reproduced as reproduced data from the other disk-shaped recording medium, n-th (n
Is a positive integer) when the reproduction of the reproduction block does not end within a predetermined time, the n +
The reproduction of the (n + 2) th reproduction block from the disc-shaped recording medium is performed without the reproduction of the first reproduction block.

The present invention is also an information signal reproducing method for outputting information data reproduced from a recording medium, wherein the information signal is divided into a plurality of data blocks, and adjacent data blocks are divided and recorded on different disk-shaped recording media. The information data is reproduced from a plurality of disc-shaped recording media in units of a reproduction block composed of a predetermined number of data blocks, and the same number of data blocks as the number of the plurality of disc-shaped recording media out of the plurality of data blocks. The error correction code data generated for each and recorded on another disk-shaped recording medium is reproduced from the other disk-shaped recording medium, and reproduced from one of the plurality of disk-shaped recording media. When there is an error in the data of the data block, or is there a certain disk-shaped recording medium among a plurality of disk-shaped recording media? When the data does not play,
The correct data to be reproduced from the certain disk-shaped recording medium is restored from the data reproduced from another disk-shaped recording medium and the reproduced error correction code data, and n +
When the reproduction of the first (n is a positive integer) reproduction block does not start at a predetermined timing, the reproduction of the (n + 1) th reproduction block from the certain disk-shaped recording medium is not performed, and the certain disk-shaped recording block is not reproduced. N + 2 from media
The reproduction of the th reproduction block is performed.

According to the present invention, when information data divided into a plurality of blocks is recorded on a disk-shaped recording medium in which adjacent data blocks are different from each other, and the reproduced data cannot be reproduced from one of the plurality of reproducing means. When the reproduction data is restored by the reproduction data reproduced from the other reproduction means, and when the n-th reproduction block is not reproduced within a predetermined time or when the reproduction processing is not started at a predetermined timing, the n + 1-th block is reproduced. Is performed without performing the reproduction process of the (n + 2) th block. As a result, video and audio signals can always be correctly reproduced in real time from a disk-shaped recording medium.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an AV server system to which an information signal reproducing device according to the present invention is applied.

FIG. 2 is a block diagram showing an embodiment of the server unit of the AV server system shown in FIG.

FIG. 3 is a block diagram showing one embodiment of the input / output unit of the server unit shown in FIG.

FIGS. 4A to 4F are schematic diagrams for explaining an embodiment of a recording position of video and audio data in the AV server system shown in FIG.

FIG. 5 is a schematic diagram showing an example of a recording format on a recording medium in the AV server system shown in FIG.

FIG. 6 is a schematic diagram showing an example of allocating sectors to each area of the recording format shown in FIG.

7 (A) to 7 (C) are schematic diagrams for explaining the operation of the information signal reproducing device of the present invention.

FIG. 8 is a flowchart showing an embodiment of the operation of the main CPU of the server unit shown in FIG.

FIG. 9 is a flowchart showing an embodiment of the operation of the CPU of the input / output unit shown in FIG.

BEST MODE FOR CARRYING OUT THE INVENTION One embodiment of an information signal reproducing apparatus according to the present invention is shown in FIG.
This will be described with reference to FIG.

First, an embodiment of an audio / video server system (hereinafter referred to as an AV server system) 20 to which the information signal reproducing apparatus of the present invention is applied will be described with reference to FIG. Video and audio data D20 output from a data supply source 22, which is a video tape recorder 21 with a playback function, is supplied to an encoder 24 of an encoding unit 23. Encoder 24
Converts the supplied video and audio data D20 into, for example, MPEG2
The encoded video and audio data D21 is formed by compression encoding using a compression algorithm conforming to the standard. The encoded video and audio data D21 encoded by the encoder 24 are supplied to the server unit 25.

The server unit 25 includes a media control unit 26 and a plurality of media units 27A1 to 27A7. Then, the encoded video and audio data D21 encoded by the encoder 24 are supplied to the media control unit 26. Each of the media units 27A1 to 27A7 includes a plurality of hard disk devices. The media control unit 26 of the server unit 25 transmits the input coded video and audio data D21 to the media units 27A1 to 27A7 in response to the write control signal supplied from the control unit 28 via the control line S1. Supply to any media unit. Also, the media control unit 27
In accordance with a reproduction control signal supplied from the control device 29 via the control line S2, the hard disk drives in the media units 27A1 to 27A7 are driven to reproduce desired encoded video and audio data from the hard disk.

The media control unit 26 has a built-in decoder unit 35 (FIG. 2), which decodes the encoded video and audio data reproduced by the hard disk device. Further, the media control unit 26 has a data distribution function, and outputs the video and audio data D22 decoded by the error code decoder 34 and the decoder unit 35 according to a distribution control signal supplied from the control device 29 via the control line S2. For example, they are selectively supplied to terminal devices 28A1 to 28A12 each having a television receiver.

In the AV server system 20, an encoder
The encoding operation of 24 and the reproducing operation of the data supply source 22 are controlled by control signals supplied from the control unit 28 via control lines S3 and S4, respectively. Also, the control section
28 monitors the operation state of the encoder 24 and the operation state of the data supply source 22 based on the operation state notification signals supplied via the control lines S3 and S4, respectively. Further, the control unit 28 monitors the operation state of the media control unit 26 based on the operation state notification signal supplied via the control line S1. Further, control such as operation start and operation end for the control unit 28 is performed by the control device 29 via the control line S5.

Next, the configuration of the server unit 25 will be described with reference to FIG. For simplicity of description, here, coded video and audio data are recorded on a hard disk device group in the media unit 27A1 among the media units 27A1 to 27A7 shown in FIG. Will be described by way of example in which encoded video and audio data are reproduced from.

First, the operation when recording the encoded video and audio data D21 supplied from the encoder 24 shown in FIG. 1 on the hard disk by the hard disk devices 271 to 276 in the media unit 27A1 in the server unit 25 will be described.

The encoded video and audio data D21 output from the encoder 24 is supplied to the error code encoder 31 via the encoder interface 30. The error code encoder 31 divides the coded video and audio data D21 into a predetermined data amount, for example, 5 by 5 bytes, and sequentially inputs and outputs 1-byte data blocks formed by dividing into 5 via a signal line S22. To the sections 32A, 32B and 32C. For example, 5
The first data block and the second data block of each divided 1-byte data block are supplied to the input / output unit 32A, and the third data block and the fourth data block are supplied to the input / output unit 32B. , The fifth data block is supplied to the input / output unit 32C. Further, the error code encoder 31 generates an error correction code from the quintuple data and supplies it to the input / output unit 32C. For example, an XOR code is used as the error correction code.

The main CPU 33 of the media control unit 26 is
A write control signal is supplied from 8 via a control line S1,
In response to this control signal, a control signal for recording the encoded video and audio signals and the error correction code in the hard disk devices 271 to 276 is supplied to the input / output units 32A to 32C via the control line S6.

Here, the configuration of the input / output units 32A to 32C will be described with reference to FIG. Since the input / output units 32A to 32C have the same configuration, only the configuration of the input / output unit 32A is shown in FIG.

A control signal supplied from the main CPU 33 via the control line S6 is supplied to the CPU 44. Further, the above-described first data block and second data block from the error code encoder 31 are supplied to buffer memories 40 and 41 each having a double buffer configuration via a signal line S22. When a control signal is supplied via the control line S6, the CPU 44 supplies a read signal via the control line S11 to supply the first data block stored in the buffer memory 40 to the hard disk device 271.
A control signal is supplied to the interfaces 42 and 43 via the control line S8 so that the second data block stored in the buffer memory 41 is supplied to the hard disk device 272 by supplying a read signal via the control line S12. Supply. As a result, the interface 42 reads the above-described first data block from the buffer memory 40 and supplies the read data block to the hard disk device 271.
Record on the hard disk by 71. The interface 43 reads the second data block from the buffer memory 41 and
2 and recorded on the hard disk by the hard disk device 272.

The configuration and operation of the input / output unit 32B at the time of recording are the same as those of the input / output unit except that the first data block and the second data block are replaced with the third and fourth data blocks, respectively. The configuration and operation of the unit 32A are the same. The configuration and operation of the input / output unit 32C at the time of recording are the same as those of the input / output unit except that the first data block and the second data block are replaced with the fifth data block and the error correction code data, respectively. The configuration and operation of the unit 32A are the same.

In this manner, the input / output units 32A to 32C can record the encoded video and audio data supplied from the error code encoder 31 on the card disk devices 271 to 275, and can also store the error correction code data on the hard disk device. 27
6 can be recorded. As a result, the hard disk devices 271 to 275 function as hard disk devices for recording and reproducing encoded video and audio data, and the hard disk device 276 functions as a hard disk device for recording and reproducing error correction code data.

FIG. 4 (A) shows the positional relationship of each data block and error correction code data on each hard disk when each data block and error correction code data is recorded on each hard disk in each of the hard disk devices 271 to 276 as described above. ) To FIG. 4 (F).

First, the arrangement of each data block when encoded video and audio data are recorded on the hard disk in the hard disk device 271 will be described with reference to FIG. The coded video and audio data are divided into a predetermined amount of data, for example, 5 every 5 bytes, and the first data block of each divided 1-byte data block is supplied to the hard disk device 271 and is continuously arranged on an empty track of the hard disk. Recorded. Therefore, when a serial number is assigned to each divided data block to identify each block, the hard disk in the hard disk device 271 includes:
As shown in FIG. 4A, data blocks 1, 6,.
11, 16, 21, 26, 31, ... are continuously recorded. Each of these data blocks 1, 6, 11, 16, 21, 26, 31,... Is the first data block of a 1-byte data block divided into five.

Also, as shown in FIG. 4B, the hard disk in the hard disk device 272 has data blocks 2,
7, 12, 17, 22, 27, 32... Are continuously recorded. These data blocks 2, 7, 12, 17, 22, 27, 32 ...
Are the second data blocks of each 1-byte data block divided into five.

Also, as shown in FIG. 4C, the hard disk in the hard disk device 273 has data blocks 3,
8, 13, 18, 23, 28, 33... Are continuously recorded. These data blocks 3, 8, 13, 18, 23, 28, 33 ...
Is the third data block of each 1-byte data block divided into five.

Further, as shown in FIG. 4D, the hard disk in the hard disk device 274 has data blocks 4,
9, 14, 19, 24, 29, 34... Are continuously recorded. These data blocks 4, 9, 14, 19, 24, 29, 34 ...
Is the fourth data block of each 1-byte data block divided into five.

Also, as shown in FIG. 4E, the hard disk in the hard disk device 275 has data blocks 5,
10, 15, 20, 25, 30, 35 ... are continuously recorded. These data blocks 5, 10, 15, 20, 25, 30, 35 ...
Is the fifth data block of each 1-byte data block divided into five.

Further, as shown in FIG. 4F, the hard disk in the hard disk device 276 has data blocks 1,
Error correction code data generated for 2, 3, 4, 5
P1, error correction code data P2 generated for data blocks 6, 7, 8, 9, 10; data blocks 11, 12, 1
Error correction code data P3 generated for 3, 14, 15
Error correction code data P4 generated for data blocks 16, 17, 18, 19, 20 and data blocks 21, 22, 23, 2
Error correction code data P5 generated for 4, 25, error correction code data P6 generated for data blocks 26, 27, 28, 29, 30 and data blocks 31, 32, 33, 34, 35
. Are generated continuously.

Next, each of the hard disk devices 271 to 276 shown in FIG.
The recording format for the hard disk in the above will be described with reference to FIG. This hard disk contains
The next area is allocated from the outer peripheral side toward the inner peripheral side. ID area in which identification data about the format method is recorded, format area in which data on the address of the recording start sector of each information data recorded on the hard disk and the size of each information data are recorded, coded video And an information data area in which audio data is recorded, and a control data area in which clip information data, which is management information of discs and management information of encoded video and audio data, is recorded.

Further, this control data area is divided into the following areas. A system information area where registration information data of clip information is recorded, a file information area where each clip information data is recorded, encoded video and audio data,
And a file allocation table (File Allocatio) in which data for managing the recording position of the error correction code data on the hard disk in cluster units is recorded.
n Table) divided into regions. Note that the reserved area is an area reserved for expansion.

FIG. 6 shows an example of the number of sectors allocated to each area when the recording format of a hard disk having a capacity of 2.15 [Gbytes] is selected as shown in FIG.

Next, an operation of reproducing encoded video and audio data from the hard disk devices 271 to 276 shown in FIG. 2 and supplying decoded video and audio data to each terminal device will be described.

Each of the terminal devices 28A1 to 28A12 shown in FIG. 1 transmits request data for video and audio data to be received to the control device 29 via the communication line S20. Control device 29
Is a control line S2 for transmitting a reproduction control signal for distributing video and audio data requested from each terminal device to each terminal device.
To the media control unit 26 in the server unit 25 via the.
The reproduction control signal supplied to the media control unit 26 is supplied to a main CPU 33 (FIG. 2) in the media control unit 26.
The main CPU 33 transmits a control signal for reproducing the requested video and audio data and error correction code data from each hard disk on the control line S6 based on the reproduction control signal.
To the CPUs 44 (FIG. 3) in the input / output units 32A to 32C, respectively.

Then, the input / output units 32A to 32C reproduce the requested video and audio data and error correction code data from each hard disk based on the control signal for reproduction supplied from the main CPU 33. Here, in order to simplify the description, the reproduction operation of the input / output unit 32A will be described with reference to FIG.

First, the CPU 44 manages the recording position of the encoded video and audio data and error correction code data on the hard disk in units of clusters, and the address of the recording start sector of each information data recorded on the hard disk. Data about the size of each information data is read from each hard disk via the interface 42 or 43 and stored in the FAT memory 47.

Next, the CPU 44 determines a recording position on the hard disk of the requested coded video and audio data and the error correction code data with reference to the data stored in the FAT memory 47, and from this recording position, A control signal is supplied to the interfaces 42 and 43 via the control line S8 so that the audio data and the error correction code data are reproduced.

The interfaces 42 and 43 control the operations of the hard disk devices 271 and 272 based on the control signal from the CPU 44 so that the requested encoded video and audio data are read from the hard disk, respectively. Thereby, for example, when the coded video and audio data and the error correction code data requested this time are shown in FIGS. 4A to 4F, the hard disk device 271 is shown in FIG. Data blocks 1, 6, 11, 16, 21, 26, 31, ...
Are continuously played back, and the hard disk device 272 is
Data blocks 2, 7, 12, 17, 22, 22 shown in (B)
Plays 27, 32 ... continuously.

Data blocks 1, 6, 11, 16, 21, 26, 31,... And data blocks 2, 7, 12, 17, 22, 27, 32,. After being supplied to the buffer memory 41 and stored once, it is supplied to the error code decoder 34 in the media control unit shown in FIG. 2 via the signal line S30. Reading of data from the buffer memories 40 and 41 is performed based on a control signal supplied from the CPU 44 via the control line S11 or the control line S12. Or
Reading of data from the buffer memory 40 and the buffer memory 41 is not shown, but the error code decoder
This is performed based on the read control signal supplied to the buffer memories 40 and 41 from.

Similarly, the hard disk device 273 is
.. Shown in FIG. 4C are continuously reproduced.
Further, the hard disk device 274 controls the data blocks 4, 9, 1 shown in FIG. 4D under the control of the input / output unit 32B.
4, 19, 24, 29, 34 ... are played continuously. The hard disk drive 275 controls the data blocks 5, 10, 15, 20, 2 shown in FIG. 4E under the control of the input / output unit 32C.
Play 5, 30, 35 ... continuously. The hard disk device 276 is controlled by the input / output unit 32C as shown in FIG.
Error correction code data P1, P2, P3, P4, P5, P shown in
6, P7, ... are played continuously.

Data blocks 3, 8, 13, 18, 23, 28, 33,... Reproduced in these hard disk devices 273 to 276,.
4, 9, 14, 19, 24, 29, 34 ... 5, 10, 15, 20, 2
5, 30, 35 ... and error correction code data P1, P2, P3, P
Are temporarily stored in one (or the other) of the buffer memories, respectively, and then supplied to the error code decoder 34 in the media control unit shown in FIG.

The error code decoder 34 performs an error correction process on the data blocks 1, 2, 3, 4, and 5 supplied from the input / output units 32A to 32C using the error correction code data P1. The error code decoder 34 performs an error correction process on the data blocks 6, 7, 8, 9, and 10 supplied from the input / output units 32A to 32C using the error correction code data P2.
Further, the error code decoder 34 outputs the data block 11,
Error correction processing is performed on 12, 13, 14, and 15 using the error correction code data P3. Error code decoder 34
Performs error correction processing on the data blocks 16, 17, 18, 19, and 20 using the error correction code data P4. In addition, the error code decoder 34 outputs data blocks 21, 22, 23,
An error correction process is performed on 24 and 25 using the error correction code data P5. Further, the error code decoder 34 performs an error correction process on the data blocks 26, 27, 28, 29, and 30 using the error correction code data P6. The error code decoder performs an error correction process on the data blocks 31, 32, 33,, using the error correction code data P7 generated. The error code decoder 34 outputs the data blocks subjected to the error correction processing in this way in the order of the block numbers, and outputs each data block based on an instruction signal indicating the transmission destination supplied from the main CPU 33 via the control line S9. The data is supplied to a designated one of the decoders 35A to 35L.

Here, the above-mentioned error correction code is obtained by dividing the data of four data blocks out of five data blocks into the remaining one.
The ability to recover each data in one data block.
Therefore, even if any one of the hard disk devices 271 to 276 does not perform a normal reproduction operation for some reason, each data of the data blocks supplied from the other four hard disk devices and the hard disk device 276 The error code decoder reproduces data to be reproduced from the hard disk device that has stopped reproducing by the error correction code data to be reproduced.
Can be restored within 34.

By the way, for example, the terminal device 28A1 transmits a reception request for video and audio data A to the control device 29, and the terminal device 28A2 transmits a reception request for video and audio data B different from the video and audio data A to the control device 29. Transmit, and further, the terminal device 28A3
A description will be given of the reproduction operation of the server unit 25 in a case where a request for receiving video and audio data C different from the video and audio data A and B is transmitted to the control device 29.

Terminal device 28A1, terminal device 28A2, and terminal device 28A3,
Request data for video and audio data A, video and audio data B, and video and audio data C to be received are transmitted to the control device 29 via the communication line S20. The control device 29 includes a terminal device 28A1, a terminal device 28A2, and a terminal device.
A reproduction control signal for distributing the video and audio data A, the video and audio data B, and the video and audio data C requested from the terminal device 28A1, the terminal device 28A2, and the terminal device 28A3, respectively, to the control line S2. To the media control unit 26 in the server unit 25 via the. The playback control signal supplied to the media control unit 26
It is supplied to the CPU 33. Based on the reproduction control signal, the main CPU 33 transmits, via a control line S6, a control signal for reproducing the requested video and audio data A, B and C and error correction code data of these data from each hard disk. To the CPUs 44 in the input / output units 32A to 32, respectively.

As shown in FIG. 3, the CPU 44 manages the recording positions of the encoded plural kinds of video and audio data and the error correction code data on the hard disk in cluster units, and the data are recorded on the hard disk. The data of the address of the recording start sector of each information data and the size of each information data are read from each hard disk and stored in the FAT memory 47.

Next, the CPU 44 determines a recording position on the hard disk of the requested coded video and audio data and the error correction code data by referring to the data stored in the FAT memory 47, and from this recording position, To reproduce the encoded video and audio data and error correction code data, to the interfaces 42 and 43, via the control line S8,
Each supplies a control signal.

The interfaces 42 and 43 are connected to the control line S from the CPU 44 so that the requested encoded video and audio data and error correction code data are read from the hard disk, respectively.
The operation of the hard disk devices 271 to 276 is controlled based on a control signal supplied via the control unit 8. As a result, each of the encoded video and audio data and the error correction code data read from the hard disk devices 271 to 276 are supplied to one (or the other) of the buffer memory 40 and the buffer memory 41 in a time division manner, and After being stored, it is supplied to the error code decoder 34 in the media control unit shown in FIG. 2 in a time division manner.

The error code decoder 34 performs an error correction process on each of the encoded video and audio data supplied from the input / output units 32A to 32C using error correction code data. The error code decoder 34 outputs the data blocks subjected to the error correction processing in this manner in the order of block numbers for each type of encoded video and audio data, and outputs
Based on the instruction signal indicating the transmission destination supplied from U33,
Supplying the encoded video and audio data A to the decoder 35A,
Supplying the encoded video and audio data B to the decoder 35B,
The coded video and audio data C are supplied to the decoder 35C.

Each of the decoders 35A, 35B and 35C performs decoding and decompression processing on the supplied encoded video and audio data, respectively, and outputs continuous real-time video and audio data, respectively, to the terminal device 28A1, the terminal device 28A2, and the terminal device. Deliver to device 28A3.

Each of the encoded video and audio data and the error correction code data read from the hard disk devices 271 to 276 are supplied to one (or the other) of the buffer memory 40 and the buffer memory 41 in a time division manner and temporarily stored therein. Later, the data is supplied to the error code decoder 34 in the media control unit 26 shown in FIG. 2 in a time division manner, and after being subjected to error correction processing in the error code decoder 34, is distributed to the respective decoders 35A, 35B and 35C. Since each of the encoded video and audio data is subjected to decoding and decompression processing in each of the decoders 35A, 35B and 35C, they become continuous real-time video and audio data, respectively.

The coded video and audio data A, the coded video and audio data B, and the coded video and audio data C are recorded together on the hard disk. Therefore, when reproducing the encoded video and audio data A, B, and C from the hard disk, in order to minimize the movement of the recording / reproducing head of the hard disk device and to shorten the access time, for example, It is desirable to select the playback order of the encoded video and audio data A, B, and C so that the playback head moves regularly from the outer circumference to the inner circumference of the hard disk.

In order to select the reproduction order, a sorting circuit 45 shown in FIG. 3 is used. The CPU 44 obtains a recording position on the hard disk of each of the requested encoded video and audio data and the error correction code data with reference to the data stored in the FAT memory 47, and sorts the data indicating the recording position into a sorting circuit. Supply 45. The sorting circuit 45 outputs the data indicating the recording position, for example,
The data indicating the position on the outer peripheral side of the hard disk is rearranged into data indicating the position on the inner peripheral side, and supplied to the CPU 44. C
The PU 44 supplies a control signal to the interfaces 42 and 43 via the control line S8 so that each of the encoded video and audio data and the error correction code data is reproduced according to the rearranged data. Thus, the coded video and audio data and the error correction code data A, B, and C can be reproduced while the recording / reproducing head moves regularly from the outer peripheral side to the inner peripheral side of the hard disk.

Further, in the server unit 25 of this embodiment, as described below, the supply of the encoded video and audio data from the hard disk device to the decoder unit 35 can be performed without delay for a predetermined period or more. ing.

When there is a read request for video and audio data from each of the terminal devices 28A1 to 28A12, the server unit 25 collectively reads a predetermined number of data blocks, for example, 128000 * 12/5 = 307200 blocks, from each hard disk as one read block. . By reading the 307200 data blocks from each hard disk within one second by each hard disk device, different video and audio signals can be continuously supplied to the twelve terminal devices. Normally, the time required to read this 307200 data block from the hard disk is within 950 [milliseconds].
The playback capability of each hard disk device is set.

At this time, the CPUs 44 of the input / output units 32A, 32B and 32C respectively
The reading of the data of the reproduction block (n) (n is a positive integer) currently reproduced from the hard disk by the hard disk device is performed within a predetermined time, for example, 950 [milliseconds].
Is determined within the next playback block (n +
Monitoring is indirectly performed by determining whether the reproduction of 1) has started at a designated timing, for example, 2 seconds after the start of reproduction. 7A to 7C.
In the example, each of the regions R indicated by oblique lines is a margin time, and this time corresponds to an overhead time required when performing switching control of the reproduction block.
[Milliseconds]. Therefore, the reproduction block (n)
If it takes 950 [milliseconds] or more for reproduction of the reproduction block (n + 1), reproduction of the reproduction block (n + 1) cannot be started from a predetermined timing. This data reading is performed within a predetermined time, for example,
FIG. 7 shows the read operation of each reproduction block from the hard disk when the operation is completed within 950 [milliseconds].
This will be described with reference to FIG. In this case, reading of all the reproduction blocks n, n + 1, n + 2, n + 3,.
.. Are completed within 950 [milliseconds]. Therefore, all the reproduction blocks n, n + 1, n + 2, n + 3... Are sequentially reproduced from the hard disk by the hard disk device. Each playback block shown in FIG.
The data block shown in FIG.

Next, for example, when accessing the encoded video and audio data by moving the head over the circumference where the playback block n of the hard disk is recorded, recording / reproduction occurs due to expansion and contraction due to the temperature of each member and mechanical errors. The position of the head is shifted, the encoded video and audio data of the reproduction block n cannot be read correctly, and the operation of correcting the position of the recording / reproduction head and accessing again is performed.
Referring to FIG. 7B, the operation of reading each playback block from the hard disk when the playback of the playback block n is completed in [sec] will be described. In this case, since the reading of the reproduction block n takes 1.3 [sec], the reproduction block n + 1 next to the reproduction block n is:
The reading is started at a timing 0.3 [second] later than the designated reading timing. Therefore, the read end timing of the reproduction block n + 1 also passes the specified timing, for example, 2 [sec] from the start of the reproduction operation, and as a result, the reproduction timing of the reproduction block n + 2 also becomes the specified timing, for example. The time point of 2 [seconds] has passed since the start of the reproducing operation. Similarly, this timing delay has an adverse effect on the reproduction timing of some subsequent reproduction blocks.

This delay in timing may make it impossible to supply continuous video and audio data to the terminal device. That is, due to the delay of the timing, the encoded video and audio data reproduced from this hard disk are not to be decoded, and therefore, the encoded video and audio data of the reproduced blocks reproduced from the other four hard disks, respectively. Therefore, in order to be restored using the error correction code data and supplied to the terminal device, directly,
It does not cause interruption of video and audio data, but other 4
If an error occurs in the encoded video and audio data in any one of the reproduced blocks reproduced from the two hard disks, it becomes impossible to restore the encoded video and audio data, And interruption of audio data.

In this way, if there is no delay in the reproduction timing, the encoded video and audio data are reproduced as useful encoded video and audio data, but the encoded video and audio data become invalid merely because the reproduction timing is delayed. Therefore, there is a high possibility that the delay causes interruption in the video and audio data supplied to the terminal device. That is, the correction capability of the error correction code used in this embodiment is such that even if one of the five data blocks is missing,
The data of the missing data block can be restored from the remaining four data blocks. If one data block is always invalid for a period corresponding to a plurality of reproduction blocks due to a delay, the other four data blocks can be restored. If an error occurs in encoded video and audio data even in one of the data blocks, the error directly leads to interruption of the video and audio data. Next, a reproducing operation in this embodiment will be described with reference to FIG. FIG. 7C shows an example in which reading of the reproduction block n takes 1.3 [seconds] for the same reason as described with reference to FIG. 7B, for example. Read time of playback block n is 95
Since it takes 0 [milliseconds] or more, the data of the reproduction block (n + 1) to be read next from the same hard disk is not read by the hard disk device, but is read next. The CPU 44 controls the read operation of the hard disk so that the data of the reproduction block (n + 2) is read from a designated timing, for example, 2 [seconds] from the start of the reproduction operation.

Then, the reproduction block (n +
The data of 1) is restored from the four data blocks and the error correction code data read by the other four hard disk devices by the error code decoder 34 using the above-described error correction processing, and Are supplied to the decoders.

As a result, there is no possibility that the read start timing of the reproduction block (n + 2) and thereafter by the hard disk device is delayed from the designated timing, and the video and audio data supplied to the terminal device may be interrupted.
This is lower than when the reproducing operation described with reference to (B) is performed.

Next, an example of the operation of the main CPU 33 of the media control unit 26 will be described with reference to the flowchart shown in FIG.

 The main CPU 33 starts its operation in step SP0.

In step SP1, the main CPU 33 transmits a reproduction control signal for distributing video and audio data requested from each terminal device to each terminal device via the control line S2.
Wait until supplied from 29, and the playback control signal is
When supplied from 29, the process proceeds to step SP2.

In step SP2, the main CPU 33 transmits a control signal for reproducing the requested coded video and audio data and the error correction code data from each hard disk based on the reproduction control signal for each reproduction block. As the input / output unit 32A via the control line S6.
It is supplied to the CPU 44 within ~ 32C respectively.

The main CPU 33 determines in step SP3 that the input / output unit 32A
It is determined whether the supply of the data access command to the CPU 44 within ~ 32C has been completed, and if a negative result "NO" is obtained, the process returns to step SP1; if a positive result "YES" is obtained, the process proceeds to step SP4. , A reproduction end instruction is input / output unit 3
The data is supplied to the CPU 44 in 2A to 32C, the process proceeds to step SP5, and a series of processes is ended.

Next, an example of the operation of the CPU 44 in the input / output units 32A to 32C will be described with reference to the flowchart shown in FIG.

 The CPU 44 starts its operation in step SP10.

In step SP11, the CPU 44 receives the above-described data access command from the main CPU 33, stores the content of the data access command in an internal memory (not shown), and stores the reception time of the data access command in the timer 46 (FIG. 3). Remember. Each of the data access commands corresponds to each of the reproduction blocks of the requested coded video and audio data and error correction code data. Each data access command indicates the type of the corresponding reproduction block, the reproduction start timing, and the like.

In step SP12, the CPU 44 sets each command content of the data access command to a standby state, and in step SP13
Proceed to.

In step SP13, the CPU 44 refers to the elapsed time data supplied from the timer 46, and determines whether the reception end time, for example, the elapsed time data supplied from the timer 46
It is determined whether or not the time has exceeded 200 [milliseconds]. If the time has not reached the reception end time, the process returns to step SP11 to accept the next data access command from the main CPU 33. On the other hand, if it is determined that the reception end time exceeds 200 [milliseconds] after receiving the first data access command, the process proceeds to the next step SP14. Thus, the CPU 44 stores a plurality of data access commands by repeating steps SP11 to SP13 until the reception end time.

In step SP14, the CPU 44 determines whether or not any of the waiting data access commands includes a command whose reproduction start timing indicated by the data access command has already passed. If an affirmative result “YES” is obtained in step SP14, the CPU 44 proceeds to step SP21
To inform the main CPU 33 that the data access command whose reproduction start timing has already passed is deleted, and deletes this data access command from the internal memory. Then, the process returns to step SP14 again.

If a negative result "NO" is obtained in step SP14, the CPU 44
Proceeds to step SP15, and outputs data indicating the recording position of the playback block indicated by each data access command to the FA.
Data taken out of the T memory 47 and indicating these recording positions is supplied to the sorting circuit 45. Sorting circuit 45
Sorts the supplied data indicating the plurality of recording positions so that the seek time is minimized, for example, from the outer peripheral side to the inner peripheral side of the hard disk.

Next, in step SP16, based on the data indicating the recording position rearranged in the sorting circuit 45 and the data indicating the reproduction start timing, the CPU 44 deletes the encoded video and audio data located at the outermost periphery and the error correction code data on the hard disk. The hard disk drive is controlled so as to be read from the hard disk drive.

In step SP17, the CPU 44 deletes the data access command executed in step SP16 from the internal memory.

Next, in step SP18, the CPU 44 determines whether or not there is a waiting data access command in the internal memory. When a negative result “NO” is obtained in step SP18, the CPU 44 returns to step SP14,
When an affirmative result “YES” is obtained, the process proceeds to step SP19.

In step SP19, the main CPU 33 determines whether or not a reproduction end instruction has been supplied from the CPU 33. When a negative result “NO” is obtained, the process returns to step SP11. When an affirmative result “YES” is obtained in step SP19, the process proceeds to step SP20 to end a series of processes.

In this way, the server unit 25 stores the terminal devices 28A1 to 28A
In response to the request from A12, the requested video and audio data can be supplied to the requesting terminal device without interruption.

In the above embodiment, the case where a hard disk is used has been described, but a magneto-optical disk device or an optical disk device may be used as the disk device.

Further, the information signal reproducing apparatus and the information signal reproducing method of the present invention can be applied to an AV server having only the server unit 25 as a main configuration.

Further, the information signal reproducing device and the information signal reproducing method of the present invention can be applied to systems other than the AV server system.

Further, the data supply source 22 in FIG. 1 is constituted by a video tape recorder, but the data supply source 22 is not limited to this, and various recording means such as a video disk can be applied.

INDUSTRIAL APPLICABILITY The present invention can be used in a system for distributing an information signal from a recording medium of a media unit to a terminal device as reproduction in an audio and / or video server system having a disk-shaped recording medium as a recording medium.

Claims (6)

(57) [Claims] 1. An information signal reproducing apparatus for outputting information data reproduced from a recording medium, wherein the information signal is divided into a plurality of data blocks, and the adjacent data blocks are divided and recorded on different disk-shaped recording media. A plurality of reproduction means for respectively reproducing the information data which has been performed from the plurality of disc-shaped recording media in a reproduction block unit including a predetermined number of the data blocks; and Error correction code reproducing means for generating error correction code data generated for each of the same number of data blocks and recorded on another disk-shaped recording medium from the other disk-shaped recording medium; and When there is an error in the data of the data block reproduced by one of the reproducing means,
Or, when data is not reproduced by the reproducing means of the plurality of reproducing means, correct data to be reproduced by the reproducing means is replaced with data reproduced by another reproducing means and the error correction code reproducing means. An error correction means for restoring from the error correction code data reproduced in the above, and a control means for controlling operations of the plurality of reproduction means and the error correction code reproduction means, wherein the control means is When the reproduction of the n-th (n is a positive integer) reproduction block by the reproduction means does not end within a predetermined time, n +
Without the playback of the first playback block being performed,
An information signal reproducing apparatus, wherein the operation of the plurality of reproducing means is controlled so that the (n + 2) th reproduced block is reproduced by the reproducing means. 2. The information data is divided into a plurality of data blocks for each predetermined data amount and recorded on the plurality of disk-shaped recording media, and each of the m-th data (m = 1, 2, 3,.
2. The information signal reproducing apparatus according to claim 1, wherein the data block of (...) is reproduced by an m-th reproducing means of the plurality of reproducing means. 3. An information signal reproducing apparatus for outputting information data reproduced from a recording medium, wherein the information signal is divided into a plurality of data blocks, and the adjacent data blocks are divided into different disk-shaped recording media for recording. A plurality of reproduction means for respectively reproducing the information data which has been performed from the plurality of disc-shaped recording media in a reproduction block unit including a predetermined number of the data blocks; and Error correction code reproducing means for generating error correction code data generated for each of the same number of data blocks and recorded on another disk-shaped recording medium from the other disk-shaped recording medium; and When there is an error in the data of the data block reproduced by one of the reproducing means,
Or, when data is not reproduced by the reproducing means of the plurality of reproducing means, correct data to be reproduced by the reproducing means is replaced with data reproduced by another reproducing means and the error correction code reproducing means. An error correction means for restoring from the error correction code data reproduced in the above, and a control means for controlling operations of the plurality of reproduction means and the error correction code reproduction means, wherein the control means is N + by playback means
When the reproduction process of the first (n is a positive integer) reproduction block does not start at a predetermined timing, the reproduction of the (n + 1) th reproduction block is not performed by the reproduction unit, and the reproduction unit does not perform the reproduction. An information signal reproducing apparatus, wherein the operation of the plurality of reproducing means is controlled such that the reproduction of the (n + 2) th reproduced block is performed. 4. The information data is divided into a plurality of data blocks for each predetermined data amount and recorded on the plurality of disk-shaped recording media, and each of the m-th data (m = 1, 2, 3,.
4. The information signal reproducing apparatus according to claim 3, wherein the data block of (...) is reproduced by an m-th reproducing means of the plurality of reproducing means. 5. An information signal reproducing method for outputting information data reproduced from a recording medium, the method comprising dividing into a plurality of data blocks, and adjacent data blocks being divided into mutually different disk-shaped recording media for recording. The information data is reproduced from the plurality of disc-shaped recording media in units of a reproduction block composed of a predetermined number of the data blocks, and the number of the plurality of disc-shaped recording media of the plurality of data blocks Is generated for each data block as many as
The error correction code data recorded on the other disk-shaped recording medium is reproduced from the other disk-shaped recording medium, and the data block of the data block reproduced from one of the plurality of disk-shaped recording media is reproduced. When there is an error in data, or when data is not reproduced from the certain disk-shaped recording medium among the plurality of disk-shaped recording media, correct data to be reproduced from the certain disk-shaped recording medium is transferred to another disk. When the reproduction of the n-th (n is a positive integer) reproduction block is not completed within a predetermined time, the data is restored from the data reproduced from the shape recording medium and the reproduced error correction code data. The reproduction of the (n + 1) th reproduction block from the disc-shaped recording medium is not performed, and the n +
An information signal reproducing method, wherein a second reproduction block is reproduced. 6. An information signal reproducing method for outputting information data reproduced from a recording medium, wherein the information signal is divided into a plurality of data blocks, and the adjacent data blocks are divided and recorded on different disk-shaped recording media. The information data is reproduced from the plurality of disc-shaped recording media in units of a reproduction block composed of a predetermined number of the data blocks, and the number of the plurality of disc-shaped recording media of the plurality of data blocks Is generated for each data block as many as
The error correction code data recorded on the other disk-shaped recording medium is reproduced from the other disk-shaped recording medium, and the data block of the data block reproduced from one of the plurality of disk-shaped recording media is reproduced. When there is an error in data, or when data is not reproduced from the certain disk-shaped recording medium among the plurality of disk-shaped recording media, correct data to be reproduced from the certain disk-shaped recording medium is transferred to another disk. When the reproduction of the (n + 1) -th (n is a positive integer) reproduction block does not start at a predetermined timing, the certain disk is reconstructed from the data reproduced from the recording medium and the reproduced error correction code data. The reproduction of the (n + 1) th reproduction block from the disc-shaped recording medium is not performed, and the disc-shaped recording medium is not read. Information signal reproducing method characterized in that regeneration of the n + 2 th of the reproduced blocks from is to be performed.