JP2001357628A - Information recording method, information recording medium, information recording device and information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently give redundancy to data recording by considering the distribution of a medium defect and the type of data recording and to improve error resistance by redundant information when types different in significance exist in data recording. SOLUTION: In an information recording method, an information source is encoded and recorded on a recording medium so that information contents including video information (210) and sound information (220) are constituted of local information expressing the partial state of the contents and header information which operates commonly on local information in a prescribed range. Data whose information source is encoded is packed by dividing it at every sector length on the recording medium and a pack containing the important header information is selected and is made redundant. The prescribed number of sectors are blocked. Errors are encoded on a block unit and data of the redundancy pack is dispersively allocated to the prescribed sectors in plural blocks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to enhancing the reliability of data in a recording medium such as an optical disk, and more particularly to the distribution and arrangement of redundant information and the improvement of resistance to local defects.

[0002]

2. Description of the Related Art With the development of technology for increasing the capacity of optical discs, the recording capacity has increased, and DVDs can record standard television image quality (SD) video for more than two hours. In addition, the capacity has been increased by shortening the wavelength of the light source and the like, and it has become possible to record high-definition television image quality (HD) video for a considerable time. With the increase in density, the recording area per unit information amount recorded on a recording medium such as a disk, tape, or card is reduced, so that even if defects such as scratches, dirt, and deterioration on the medium have the same size, , Data loss, that is, the amount of error increases in proportion to the increase in density. There is also a strong need for users who want to use a recording medium naked without storing it in a protective case, so there is an increasing demand for a technology that enhances protection of recorded data against such media defects and a technology that improves data reliability. Is growing.

[0003] Generally, data protection is performed by giving redundancy to recorded information using an error correction code and correcting an error that has occurred. In a conventional large-capacity recording medium such as a DVD, the same error correction code is added to all data to ensure reliability. Regarding various data arrangements on the recording medium, the most important information such as the control information of the entire system is multiplexed and recorded to enhance reliability.
No special consideration was given to content information such as video and audio to be recorded.

[0004] In a high-efficiency video / audio code such as the MPEG code used for DVD, recorded data acts on local information indicating a parameter value for each sample point and a wide range of local information in common. And header information that gives meaning. When an error occurs in some data due to a local defect, the effect of the error on the reproduction information is limited to the sample point in the local information, but the corresponding collective collection of local information in the header information Spans the whole. When data loss occurs in the header information, the reproduction of the information may be stopped in the worst case even with a small amount. Therefore, the header information is more important, and it is recognized that the protection against the defect needs to be strengthened more than the local information.

As a conventional example to be referred to, Japanese Patent Application Laid-Open No. 11-74
868 discloses an example in which, in a system for compressing and transmitting an image or the like, a bit string itself has an error resilience capability so that decoding can be performed normally even if an error occurs in important information such as header information. In this case, the specific parameter in the header information is duplicated and recorded in the header of another layer, and when the parameter in the header of the upper layer cannot be reproduced correctly, the header of the lower layer which appears later is used. To obtain the correct value from the same parameter in the upper layer, or conversely, when the parameter in the upper layer header can be reproduced correctly and the same parameter in the lower layer header Uses parameter values. Further, it is described that the information source encoded data is stored in a recording medium.

In this example, the error resilience capability in the information source coding layer is improved for the transmission system.
Specific to package recording media such as optical discs,
No consideration is given to the form of error occurrence in the hierarchy relating to the physical structure. That is, for example, in DVD, the minimum unit of recording is a sector of 2048 bytes, and the unit of error correction is 3276.
It is an 8-byte block, and once an error occurs,
Not only the data in the defective portion is not lost, but a long burst error occurs in sector units, and a unit in which data cannot be reproduced due to an uncorrectable error is a block.

[0007] In such an environment, there is a need for a method of improving error resilience so as to give the best possible viewing sensation.

[0008]

In view of the above situation,
The following are taken up as important issues for improving the reliability of recorded data in an actual high-density recording device.

One is that when information recorded on a recording medium includes a plurality of types of data having different degrees of importance, the distribution of the positions and sizes of defects occurring on the recording medium, the size and the size of each type of data to be recorded, and the like. The purpose is to efficiently provide redundancy for each type of data in consideration of the relationship between each type of data. Further, in order to make use of this redundant information to increase the resistance to errors, a plurality of types of redundant information are optimally arranged in accordance with the characteristics of each data.

Here, as the amount of redundant information increases, the error correction capability improves. However, since the recording capacity is required, the effective recording density decreases, and the redundant information is widely distributed. It is necessary to consider that the longer the time required for reading and writing becomes, the longer the time required. When deciding the amount of redundant information, the method of providing redundant information, and the arrangement thereof, it is important to optimize in consideration of such conditions that conflict with enhanced protection against data loss.

The degree of error resilience given to data is as follows:
Considering the scale of the effect of deterioration of reproduction image quality and sound quality due to media defects on the viewers who ultimately provide audiovisual information, i.e., the recording capacity required for redundant information and its effect It is good to set in consideration of the relationship with.

[0012] Accordingly, an object of the present invention is to optimally allocate redundancy and optimally arrange redundant information according to the characteristics of a recording medium and the importance of data, thereby efficiently improving the total error resilience to local defects. Is to do.

[0013]

According to the information recording method of the present invention, an information content including video information and audio information is converted into local information expressing a local state of the content and local information in a predetermined range. In an information recording method for recording on a recording medium by encoding the information so as to be composed of header information that acts in common, a step of packing the data encoded by the information source for each sector length on the recording medium, Selecting a pack containing important header information to make it redundant, blocking a certain number of sectors, and performing error correction coding in units of the block;
And distributing the data of the redundant pack to predetermined sectors in the plurality of blocks in a distributed manner.

A method according to a second aspect of the present invention, in the method according to the first aspect, wherein the step of making redundant includes recording a pack including the important header information in a predetermined sector in the plurality of blocks. And thereby, even if a predetermined number of blocks of the plurality of blocks in which the important header information is recorded cannot be reproduced, obtaining the important header information from another block. It is made possible.

A method according to claim 3, wherein the step of making redundant includes a step of performing a second error correction coding, whereby the redundant pack is allocated. The pack including the important header information can be restored even if a predetermined number of blocks of the plurality of blocks cannot be reproduced.

According to a fourth aspect of the present invention, there is provided the information recording medium, wherein the information content including the video information and the audio information is combined with the local information expressing the local state of the content and the header information commonly acting on the local information within a predetermined range. In an information recording medium on which information source encoding has been performed and recorded as described above, the information source encoded data is divided into packs for each sector length on the information recording medium, and a pack containing important header information is selected. The data is redundantly encoded by error correction coding in units of a block composed of a fixed number of sectors, and the data of the redundant pack is dispersedly arranged in predetermined sectors in the plurality of blocks.

According to a fifth aspect of the present invention, in the recording medium according to the fourth aspect, the redundancy records the pack including the important header information in a predetermined sector in the plurality of blocks. This makes it possible to obtain the important header information from other blocks even if a predetermined number of blocks of the plurality of blocks in which the important header information is recorded become unplayable. It is made possible.

According to a sixth aspect of the present invention, in the recording medium of the fourth aspect, the redundancy includes a second error correction coding, whereby the plurality of blocks to which the redundant pack is allocated are assigned. Wherein the pack including the important header information can be restored even if a predetermined number of blocks cannot be reproduced.

According to a seventh aspect of the present invention, in the information recording apparatus, the information content including the video information and the audio information is combined with the local information expressing the local state of the content and the header information commonly acting on the local information in a predetermined range. In an information recording apparatus that encodes information source and records it on a recording medium as described above, packing means for dividing the source encoded data into individual sector lengths on the recording medium and packing the data, and important header information And an error correction coding unit that blocks a fixed number of sectors and performs error correction coding on a block-by-block basis, wherein the redundancy unit includes: The data of the coded pack is distributed and assigned to predetermined sectors in the plurality of blocks.

An apparatus according to an eighth aspect of the present invention is the apparatus according to the seventh aspect, wherein the redundancy means records a pack including the important header information in a predetermined sector in the plurality of blocks in an overlapping manner. Thereby, even if a predetermined number of blocks of the plurality of blocks in which the important header information is recorded cannot be reproduced, the important header information can be obtained from other blocks. It is characterized by.

According to a ninth aspect of the present invention, in the device of the seventh aspect, the redundancy means includes means for performing a second error correction coding, and the means for performing the second error correction coding includes:
Even if a predetermined number of blocks out of the plurality of blocks to which the redundant packs are assigned cannot be reproduced, a pack including the important header information can be restored.

An information reproducing apparatus according to a tenth aspect is an information reproducing apparatus for reproducing the information recording medium according to the fourth aspect,
Error correction decoding means for decoding the error correction code to reproduce the block, means for selecting the data of the redundant pack from predetermined sectors in the block, and restoring the pack containing the important header information And restoring means for restoring data of the pack from data of other blocks in the plurality of blocks in which data of a redundant pack is distributed when the block cannot be reproduced. It is something to do.

According to an eleventh aspect of the present invention, in the device of the tenth aspect, the information recording medium is the one described in the fifth aspect, and the restoring means reproduces the block in which the important header information is recorded. When it is not possible, the important header information obtained from another block is substituted.

According to a twelfth aspect of the present invention, in the device of the tenth aspect, the information recording medium is the one described in the sixth aspect, and the restoration means decodes the second error correction code. 2 error correction decoding means.

In the above configuration, when an uncorrectable error due to a medium defect occurs in important header information, it is redundantly recorded in another location together with related local information in a predetermined range. It is possible to recover the erroneous header information by using the redundant information for the amount of error. The data amount of the header information is smaller than the data amount of the local information, and it is possible to efficiently enhance error resilience.

When an uncorrectable error due to a medium defect occurs in the local information, the information in that part is lost, but the damage is limited to the local area and does not affect the normally reproduced part. Absent.

When data loss is so severe that it is impossible to restore the header information from the redundant information, the associated local information in a predetermined range is usually lost. Even if the content can be restored, the desired content can no longer be reproduced.

In order to restore the correct header information from the redundantly recorded header information, it is necessary to arrange the redundancy information in a predetermined part which is specified in advance. And the circuit can be simplified.

In the recording apparatus, the redundancy information may be periodically inserted into the recording stream during the continuous encoding process during recording. In addition, in the process of continuous decoding at the time of reproduction, redundant information is periodically collected from the reproduced stream, and the restoration processing is performed using the redundant information that has been reserved only when data loss occurs. do it.

According to the present invention, the header information is dispersedly recorded over a wide area on the recording medium, and an error correction capability is provided so that the entire header information can be restored even if a part is lost. Here, in order to effectively provide error correction capability, the range in which the header information and the redundant information are dispersed is adjusted to the entire range in which the local information related to the header information is arranged.

This was determined in consideration of the effect on the contents due to the loss of data. If the header information deteriorates faster than the local information due to an increase in unrecoverable errors, information cannot be reproduced even though reproducible local information remains. Conversely, if the deterioration of the local information progresses quickly, even if the header information is restored, the local disorder of the reproduction information becomes large and the reproduction becomes unbearable, resulting in a quality outside the allowable range.

Therefore, the quality of the reproduced information such as video and audio is deteriorated by the loss of the header information.
By balancing the degree of redundancy given to each viewer so that the deterioration caused by the loss of local information is felt to the same extent by the viewer's sense, error resilience can be efficiently enhanced with the least amount of redundancy. Become.

In other words, until the number of medium defects increases so that the reproduction quality of the content falls below the permissible limit, sufficient redundancy should be provided so that fatal errors do not occur in the header information. .

At the same time, consideration was given to ensuring the minimum necessary access performance. Even if the header information is distributed over an excessively wide range to increase the redundancy and improve the tolerance against errors, when reading the redundant information and restoring the header information, it takes a long time to exceed the allowable range. Useless. That is, the video is stopped or the sound is interrupted, and the reproduction quality of the content is out of the allowable range.

Therefore, the range in which the redundant information of the header information is arranged is defined by the access time determined by the access performance of the reproducing apparatus and the capacity of the buffer memory normally mounted on the reproducing apparatus.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

Embodiment 1 FIG. 1 shows the configuration of the information recording apparatus of the present invention. The video information 210 and the audio information 220 that have been digitized and captured are first subjected to information source encoding by information source encoding means 111 and 112, respectively, and are encoded into a video encoded stream 211 and an audio encoded stream 2 respectively.
21. This step includes MPEG1, MPEG
2. Use a high efficiency coding code such as MPEG4. The types of the source-encoded data are roughly divided into local information indicating parameter values for each sample point, and header information that acts and gives meaning to a wide range of local information in common. An encoded stream of the acoustic code is configured.

In the MPEG, a moving image is, in order from the lower level, a macroblock, which is a minimum unit of encoding composed of 8 × 8 pixels in a plane, a slice composed of a set of macroblocks in a row, and an interlaced scanning method. , A frame (also referred to as a picture) composed of one field, which is a set of slices in one vertical scanning period, and a frame (also referred to as a picture) composed of two odd fields, and a set of pictures related to performing predictive coding by motion compensation (that is, complete motion compensation prediction GOP (Group of Pictures)
For example, image information is hierarchically encoded according to the spatial and temporal size of the information handled collectively, and the common parameter that acts on the sample value in the layer at the beginning of the data of each layer as header information Give. The local information of the corresponding pixel portion is arranged following each header information.

Next, means for packing the encoded stream 11
In steps 2 and 122, the coded stream that has been coded efficiently by the information source coding means is divided into sectors each of which is the minimum access unit when recording or reproducing on a recording medium. When video and audio are encoded by the information source encoding unit, the video encoding unit and the audio encoding unit encode the video and audio independently, and after encoding, synthesize as a series of streams. At this time, in order to prevent both from coexisting in the same sector in consideration of simplification of data management,
Also, in order to arrange video data and audio data independently so that they can be accessed independently for each batch processing unit such as a picture unit or a GOP unit, each stream is previously rounded to a unit called a pack. , Adjust the length of the pack so that those breaks are aligned with sector boundaries. In other words, the data protruding from the sector is packed by performing a stuffing process of adding a useless bit so that the length of the processing unit after encoding becomes an integral multiple of the sector length. For this reason, the content recorded on the recording medium is divided into sectors for recording video and audio, each of which is recorded on the medium.
And an audio pack 222 (collectively referred to as an information pack).

When recording video and audio, it is common to record not only these high-efficiency coded streams but also control information and system information accompanying the content to be recorded, such as recording conditions and time information. It is. The control data 231 including such information is collected into a control pack 232, which is a type of information pack, by the control data packing unit 132, and is recorded together with the related information pack at an appropriate position on a recording medium.

The data converted into the video pack 212, the audio pack 222, and the control pack 232 by the packing units 112, 122, and 132 are arranged in the synthesizing unit 101 in such an order that the time relationship at the time of reproduction becomes appropriate for the reproduction apparatus. Are combined into a series of streams. If the stream 201 thus synthesized is a conventional apparatus, it is sent to the error correction encoding means 105 as it is, where an error correction code having a uniform correction capability is added to all data.

In the present invention, in order to prevent loss of the header information of high importance, the first stage of redundancy is performed on a sector including a pack including such header information of high importance. The first stage of redundancy is positioned as an error recovery measure using the preliminary information in case an error that cannot be corrected by an error correction code occurs and data loss occurs. The processing is performed by packing units 112, 122, and 13.
2 to determine whether or not the pack includes header information with high importance when the encoded data is divided,
If it is determined that the pack is an important pack, the pack is sent out with an important tag indicating that fact. Other packs are usually sent out as packs. The synthesizing means 101 forms the synthesized stream 201 by arranging the packs while preserving the association between the important tags and the packs.

The composite stream 201 is input to the important data redundant means 102. In this case, the important tag determining unit 103 determines whether or not the pack in the input stream has an important tag. If the important tag is attached, the pack is temporarily stored in the temporary storage unit 104 as a target pack for redundancy. The output of the important data redundancy unit 102 is a redundant stream 202 in which important packs and normal packs are mixed. There are several methods for redundancy used here. One is a repetition record. Regarding the important packs, the same contents temporarily stored are arranged so as to be repeated a plurality of times at predetermined intervals. In other words, the important packs having the same contents are repeatedly inserted one by one a prescribed number of times at predetermined intervals into a row of normal packs that are repeated without repeating the same contents.

At this time, the position where the important pack is inserted is detected by receiving an error correction block timing signal 203 generated at an appropriate point in time in accordance with the format of the error correction block from the error correction coding means 105 at the next stage.

The redundant stream 202 is inputted to the error correction coding means 105. There, an error correction encoding process is performed on all the packs input to the error correction encoding means 105 so as to provide the error correction capability equally.
Block coding is applied to the error correction coding processing, a predetermined number of sectors for recording packs are collectively treated as one block, and an error correction code is added to information data in the pack in units of blocks. A well-known technique such as a Reed-Solomon code is applied to the error correction code. The arrangement of the information data and the error correction code in the block follows the rules defined in the format of the error correction block. Similarly, in accordance with the format, an error correction coded stream is output in a predetermined code word order and sent to the recording modulation means. In the recording modulation means,
For example, the signal is digitally modulated by a method suitable for the characteristics of the recording medium, such as a (1,7) RLL code or an 8/16 modulation code, to obtain a recording signal 206, which is recorded on the recording medium by a recording unit (not shown).

When the important data redundancy means 102 makes the important pack redundant, the redundant stream 20
It is stated that important packs are arranged at predetermined intervals in 2,
The arrangement is related to the format of the error correction block in the error correction means 105. The purpose of the important data redundancy is to avoid data loss due to error correction in one error correction block, that is, even when data cannot be reproduced. Therefore, this is realized by arranging important packs having the same contents in different error correction blocks.

FIG. 2 shows the relationship between the header information and local information of the high-efficiency encoded data, the information pack, and the composite stream. It is assumed that a portion described as a processing unit in the figure is recorded in an integer number of sectors. Synthetic stream 201
Starts with header information, followed by local information. Since one processing unit generally includes several information source coding layers, header information is also included in a plurality of locations. A stuffing bit is added in order to adjust the length so that the processing sector ends at the end of the processing unit. The composite stream of the processing unit shown here is divided into respective information packs for each part indicated as a pack in the figure. Each of the divided information packs is recorded in the sector of the recording medium. Among them, a pack marked as an important pack in the figure is an important pack to be subjected to redundancy. Since the redundancy requires a considerable amount of recording capacity, it is not always necessary to make all header information redundant. It is also possible to select only those effective in terms of enhancing error resilience and make them redundant. Here, for the sake of simplicity, an example is shown in which only the pack including the header information placed at the head is treated as an important pack and redundancy is performed.

FIG. 3 shows an example of the arrangement of error correction blocks and sectors and important packs and normal packs. This is an example in which a block of an error correction code is composed of 32 sectors. When the recording capacity of the sector is 2048 bytes (that is, 2 KB), the size of the error correction block is 64 bytes.
KB. The leading one sector among the 32 sectors of each error correction block is used as an important pack recording sector, and the remaining three sectors are used as important sector.
One sector is allocated for recording a normal pack. If the important packs are duplicated, that is, the redundancy is set to 50%, the ratio of the capacity allocated to the redundancy of the important packs to the normal packs in the composite stream is approximately (1/32) ) × (１ ／) = 1.61%. By selecting important header information and making it an important pack, it is possible to effectively use such a small recording capacity and enhance error resilience without applying redundancy to the entire stream. Is possible.

When the ratio of data to be made redundant is high, a plurality of sectors in each error correction block can be allocated for important pack recording. When allocating two sectors to this, for example, the first sector and the first
The same defect may be avoided as much as possible by distributing the important packs in seven sectors and assigning important packs.
Important packs may be allocated to the sector and the second sector in a concentrated manner to easily accommodate a long header.

In any case, the arrangement of sectors for recording important packs must be specified as an error correction block format. Here, apart from the case where a single arrangement method is specified as a format, when a plurality of arrangement methods are selectable, all data of the recording medium or each error correction block is provided with any redundancy method. A flag or control information indicating whether or not the above is applied is registered by providing a predetermined place in an appropriate place such as a control information area of a recording medium or a control information area of each sector.

FIG. 4 shows an example in which important packs are made redundant. Here, the error correction block is composed of 32 sectors, and the first sector of each block is reserved for redundant recording of important packs. It is assumed that the processing unit of a composite stream of a certain content has a data amount equivalent to a 4-block length, and one important pack including header information is included therein. At this time, the important pack is repeatedly recorded four times in each head sector of the four error correction blocks. Other normal packs are recorded in the second to 32nd sectors of each error correction block in 31 packs in the order in which they are arranged in the composite stream.

Embodiment 2 FIG. 5 shows the configuration of the information reproducing apparatus of the present invention. This playback device plays back content such as original audiovisual information from a recording medium recorded by the recording device shown in FIG. Here, in a state in which a reproduced signal is lost due to a defect on a recording medium and an error occurs in reproduced data and the error cannot be corrected by the error correction means, fatal data loss is avoided as much as possible by the present invention. Explain that you can play while playing.

The reproduction signal 406 reproduced from the recording medium is demodulated by the recording / demodulation means 306 and the reproduction stream 40
Take out as 5. Next, the error included in the reproduction stream 405 is corrected by the error correction decoding means 305,
Output as an error correction decoded stream 402. Here, if all errors can be corrected, no problem occurs. The present invention is a countermeasure against a case where an uncorrectable error occurs in the error correction decoding stream 402 and data is lost.

The cause of the error is, as described above, a defect such as a scratch, dirt, or deterioration of the medium. These are collectively referred to as defects.
For example, in addition to a state in which the recording data cannot be detected due to contamination of the medium, a signal reading unit (such as an optical pickup) that scans a recording track by using a servo.
On the other hand, when the servo comes off due to the fact that the correct servo information is not supplied for a certain period of time, even if the servo system is restored after the defective portion on the recording medium has been passed, the reproduction signal is not Also includes the case where is not obtained. Therefore, in general, the length of the defect is longer than the length of the defect on the recording medium.

The error correction decoded stream 402 is input to the important data restoring means 302. The important data restoring means 302 receives an error correction block timing signal 403 generated at an appropriate time by the error correction decoding means 305 in accordance with the format of the error correction block, and inputs the sector in which the important pack on the format is located. At this time, the data of the sector is selected as an important pack and temporarily stored in the temporary storage unit 304.

When there is no data loss, all data is correctly reproduced, and thus the temporarily stored important pack information is not used as redundant information. If there is data loss, the error correction decoding unit 305 notifies the important data restoration unit 302 of the fact that the corresponding block cannot be reproduced using the error correction disable signal 404. Upon receiving this notification, important data restoring means 302
Tries to restore the missing data according to the redundancy method.

When the redundancy method is the repetitive recording as already described with reference to FIG. 4, the contents of the important pack included in another block in the same processing unit are substituted. When data loss occurs in the first block of the processing unit, the process waits for the important pack to be normally reproduced in subsequent blocks. When there is an important pack that has been normally reproduced in the same processing unit and is temporarily stored in the temporary storage unit 304 without being used, it can be used.

If the lost important pack can be restored by the above processing, the important data restoring means 302 arranges the pack at a regular position and outputs it as a restored stream 401.

The restored stream 401 is input to the separating means 301 and separated into streams for each type of information pack.
The video pack 412, the sound pack 422 reproduced here,
The control packs 432 are separated from each other. Each of the reproduced packs is provided with a video information depacking unit 312, an audio information depacking unit 322, and a control information depacking unit 3.
At 32, unnecessary bits for stuffing are deleted and converted into a video encoded stream 411, an audio encoded stream 421, and control data 431. In the information source decoding means 311 and 321, the video information 4 from these streams 411 and 421 respectively.
10. The content including the audio information 420 is reproduced.
The control data 431 is used for device control during reproduction and an interface with the user.

Embodiment 3 FIG. 6 shows another example of redundancy of important packs. In addition to the error correction coding applied to the entire redundant stream, the second error correction coding is applied to only important packs. This second error correction coding is included in the redundancy process. Here, similarly to FIG. 4, the error correction block is composed of 32 sectors, and the first sector of each block is reserved for redundant recording of important packs. It is assumed that a processing unit of a composite stream of a certain content has a data amount equivalent to a 4-block length and includes two important packs including header information. At this time, the normal packs are recorded in the second sector to the 32nd sector of each error correction block in 31 packs in the order in which they are arranged in the composite stream, as in the case of FIG.

The second error correction code is used in the important data redundancy means 1 in the block configuration of the information recording apparatus shown in FIG.
02 by means of a second error correction coding circuit arranged in
It is added based on the format of the second error correction code.
Here, the important pack subjected to the second error correction coding is arranged in a redundant recording sector of a predetermined important pack in the important data redundancy means 102. The entire stream thus redundant is further sent to the error correction encoding unit 105 for error correction encoding as described above.

At the time of reproducing information, the error correction decoding means 305 in the block configuration of the information reproducing apparatus shown in FIG.
The second error-correction-coded important pack is included in the error-correction decoded stream output from. The important data recorded in the redundant recording sector in the error-correction decoded stream is subjected to error-correction decoding based on the format of the second error-correcting code and restored by the important-data restoring means 302.

For the two important packs, 2
There is also a method of recording twice in each head sector of the error correction block of the block. However, assuming that the range of damage that occurs when a defect occurs is expanded to some extent, such as when data is erroneous due to a wide range of dirt such as fingerprints, it is advantageous to expand the range in which redundant data is distributed as much as possible. is there.

For example, in the above-described example where important packs for two sectors are arranged in a total of four sectors at the beginning of each of the four blocks. If the sector is wrong, one of the important packs cannot be reproduced. On the other hand, if the first four sectors in each of the four blocks are collectively subjected to the second error correction coding, the important packs can be restored even if any two sectors are erroneous. Some data included in sectors other than the important pack may be lost, but this is local information and has little effect on the quality of the reproduced information.

For this purpose, the second error correction coding is applied to the data of two important packs. A code equivalent to two sectors can be added as an error correction code. In this way, the two important packs are error-correction-coded so as to have a length corresponding to four sectors, and are recorded in the first sector of each block. In this way, since the important header information can be restored, the probability of avoiding fatal data loss is increased, so that the quality deterioration of the reproduction information is minimized.

The method described in the above embodiment is a technique for enhancing error resilience by devising the arrangement of data in recording sectors when recording information data on a recording medium. Therefore, it is of course possible to provide even stronger data protection in combination with the technology that enhances error resilience by multiplexing header information at the time of source coding, which was taken up as a conventional technology. It is.

[0067]

When the information recorded on the recording medium includes a plurality of types of data having different degrees of importance, the distribution of the positions and sizes of the defects occurring on the recording medium, the size of each type of data to be recorded, Considering the relationships and connections between the types of data, we have effectively added redundancy to each type of data,
Resistance to errors due to defects and the like can be efficiently increased.

That is, the error resilience can be enhanced while the recording capacity allocated to the redundant information is reduced.

Further, error tolerance can be enhanced while adding a small amount of time for reading or writing redundant information.

Further, when an uncorrectable error occurs due to a medium defect, regarding the deterioration of the reproduction information such as video and audio, the deterioration caused by the loss of the header information and the deterioration caused by the loss of the local information are considered by the viewer. By balancing the degrees of redundancy given to each other so as to feel the same degree, it is possible to minimize the perceived quality deterioration of the viewer with respect to the amount of occurrence of medium defects.

In particular, according to the first, fourth, seventh and tenth aspects of the present invention, a pack including important header information is selected and made redundant, so that storage capacity is effectively used. Error resilience can be enhanced. That is, the amount of header information is smaller than the data amount of local information, and error resilience can be efficiently enhanced. Further, even when an error cannot be corrected in one error correction block, data loss due to this can be avoided. Further, since information for redundancy is arranged in a predetermined sector, processing is easy during both recording and reproduction, and the circuit of a device for recording and reproduction can be simplified.

According to the second, fifth, eighth and eleventh aspects of the present invention, even if an error occurs in important header information, other header information recorded in another block is substituted. be able to.

According to the third, sixth, ninth, and twelfth aspects of the present invention, even if a part of important header information is lost, the whole can be restored.

According to the fourth, fifth and sixth aspects of the present invention, the error tolerance of the recording medium can be efficiently enhanced with the minimum redundancy.
It is easy to use the recording medium naked without accommodating it in the protective case, and the convenience for the user can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an information recording device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of an encoded stream and a pack according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a sector and an error correction block according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a pack and an error correction block according to the first embodiment of the present invention.

FIG. 5 is a block diagram of an information reproducing apparatus according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration of a pack and an error correction block according to a third embodiment of the present invention.

[Explanation of symbols]

101 synthesis means, 102 important data redundancy means,
103 important tag determination means, 104 temporary storage means, 105 error correction coding means, 106 recording modulation means, 111 information source coding means for video information, 1
12 means for packing a video encoded stream, 121
Information source encoding means for audio information, 122 audio encoding stream packing means, 132 control data packaging means, 201 synthesized stream, 202 redundant stream, 203 error correction block timing signal, 205 error correction encoding stream, 206
Recording signal, 210 video information, 211 video encoding stream, 212 video pack, 220 audio information, 221 audio encoding stream, 222 audio pack, 231 control data, 232 control pack,
301 separation means, 302 important data restoration means,
304 temporary storage means, 305 error correction decoding means, 306 recording and demodulating means, 311 video information information source decoding means, 312 video pack depacking means, 321 audio information information source decoding means, 322
Means for depacking the sound pack; 332 means for depacking the control pack; 401 restored stream; 402
Error-corrected decoded stream, 403 error-corrected block timing signal, 404 error-correctable signal, 40
5 playback stream, 406 playback signal, 410
Played video information, 411 played video encoded stream, 412 played video pack, 420 played audio information, 421 played audio encoded stream, 422 played audio pack, 431 played control data, 432 played control pack .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 20/18 576 G11B 20/18 576Z

Claims (12)

[Claims] 1. An information source encoding method for encoding information content including video information and audio information into local information representing a local state of the content and header information commonly acting on a predetermined range of local information. In the information recording method of recording on a recording medium, a step of dividing the source-encoded data for each sector length on the recording medium and packing it, and a step of selecting a pack containing important header information and making it redundant Information comprising the steps of: dividing a fixed number of sectors into blocks and performing error correction coding in units of the blocks; and distributing and assigning the data of the redundant packs to predetermined sectors in the plurality of blocks. Recording method. 2. The step of making redundant includes a step of recording a pack including the important header information in a predetermined sector in the plurality of blocks in an overlapping manner, thereby recording the important header information. 2. The apparatus according to claim 1, wherein even if a predetermined number of blocks of the plurality of blocks cannot be reproduced, the important header information can be obtained from other blocks. Information recording method. 3. The step of performing the second error correction encoding in the step of performing redundancy, whereby a predetermined number of blocks of the plurality of blocks to which the redundant pack is allocated are reproduced. 2. The information recording method according to claim 1, wherein a pack including the important header information can be restored even if the pack cannot be used. 4. An information source coding method for encoding information content including video information and audio information so as to be composed of local information expressing a local state of the content and header information commonly acting on local information in a predetermined range. In the information recording medium recorded with the data, the information source coded data is divided into packs for each sector length on the information recording medium, and a pack including important header information is selected for redundancy, and is composed of a fixed number of sectors. An information recording medium in which error correction coding is performed in units of blocks, and the data of the redundant pack is dispersedly arranged in predetermined sectors in the plurality of blocks. 5. The redundancy includes recording a pack including the important header information in a predetermined sector in the plurality of blocks in an overlapping manner, thereby recording the important header information. 5. The information recording apparatus according to claim 4, wherein even if a predetermined number of blocks of the plurality of blocks cannot be reproduced, it is possible to obtain the important header information from another block. Medium. 6. The method according to claim 1, wherein the redundancy includes a second error correction coding, so that a predetermined number of blocks of the plurality of blocks to which the redundant pack is allocated cannot be reproduced. 5. The information recording medium according to claim 4, wherein a pack including the important header information can be restored. 7. Information source encoding such that information content including video information and audio information is composed of local information expressing a local state of the content and header information commonly acting on local information in a predetermined range. Means for recording information source coded data in a sector-by-sector length manner on the recording medium and packing it, and selecting a pack containing important header information for redundancy And an error correction coding unit that blocks a certain number of sectors and performs error correction coding in units of the blocks, wherein the redundancy unit converts the data of the redundant pack into a plurality of blocks. An information recording device which is allocated to predetermined sectors in a block in a distributed manner. 8. The redundancy means records a pack including the important header information in a predetermined sector in the plurality of blocks in an overlapping manner, whereby the plurality of packs on which the important header information is recorded are recorded. 8. The information recording apparatus according to claim 7, wherein even if a predetermined number of blocks among the blocks cannot be reproduced, the important header information can be obtained from another block. 9. The redundant means includes a means for performing a second error correction coding, wherein the means for performing the second error correction coding comprises: 8. The information recording apparatus according to claim 7, wherein a pack including the important header information can be restored even if a predetermined number of blocks cannot be reproduced. 10. An information reproducing apparatus for reproducing an information recording medium according to claim 4, wherein: an error correction decoding means for decoding the error correction code to reproduce a block; and a predetermined sector in the block. Means for selecting the data of the redundant pack from the following, and restoring means for restoring the pack containing the important header information, wherein the restoring means, when the block cannot be reproduced, the data of the redundant pack An information reproducing apparatus for restoring the data of the pack from the data of another block in the plurality of blocks in which the data is distributed. 11. The information recording medium according to claim 5, wherein, when the block in which the important header information is recorded cannot be reproduced, the important header information obtained from another block. The information reproducing apparatus according to claim 10, wherein 12. The information recording medium according to claim 6, wherein the restoration means includes a second error correction decoding means for decoding the second error correction code. The information reproducing apparatus according to claim 10.