JP3499280B2 - Recording medium and reproducing apparatus therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as an optical disc and a reproducing apparatus thereof.

[0002]

2. Description of the Related Art In recent years, a disc reproducing device for reproducing an optical disc on which audio and video are recorded has become widespread and is widely used as a reproducing device for movie software, karaoke and the like. Recently, a device for reproducing an optical disc in which audio and video data is digitally recorded has appeared, and is commercially available as, for example, a karaoke system. Since this optical disc has the same size as a CD (compact disc), it has an advantage that the entire apparatus can be downsized.

As a compression method for audio and video data recorded digitally as described above, the international standard MPEG is used.
(Moving Picture Image Coding Expert Group) 1 is adopted. The MPEG1 system is a system for variable length compression of data. FIG. 5 is a diagram showing an example of a recording format of such variable length data on an optical disc. Here, the video data and the audio data are recorded separately in sector units. Each sector is composed of a header area 11 and a data area 12, and compressed data of video or audio is recorded in the data area 12.
Also, in order to keep the video and audio synchronized, four consecutive
One audio sector A is arranged after one video sector V to form a data stream. However, in such a method in which variable-length data is divided into fixed-length sector units, time management on the playback device side becomes complicated,
There is a problem that random access becomes difficult.

In order to improve this, the following method is used. In this method, as shown in FIG. 6, data is recorded on the optical disc in units called data units (DUT). This data unit is formed by dividing both video data and audio data in units of a predetermined reproduction time (for example, 1 second). FIG. 7 is a diagram showing the structure of this data unit. As shown in the figure, the data unit is composed of header data 21, video data 22 and audio data 23. Both the video data 22 and the audio data 23 are variable-length compressed data. The header data 21 includes management information necessary for reproducing the compressed data in its own data unit, such as position information of the video data 22 and the audio data 23 in its own data unit. By the way, in this method, if the header data is destroyed for some reason and cannot be corrected, the position information of the video data and the audio data in the data unit cannot be discriminated and correct reproduction cannot be performed. In this case, in the conventional disc reproducing apparatus, muting is applied only during the reproducing period of the data unit. Here, the reproduction time in units of data units can be arbitrarily selected, but if it is too short, the proportion of the header data 21 in the entire recording data increases, and the amount of recordable video and audio data decreases. For this reason, about 1 second is appropriate as the reproduction time. However, when muting for one second is applied, it is inevitable that the viewer feels uncomfortable.

[0005]

As described above, in reproducing a recording medium in which the variable-length compressed video data and audio data are divided into a plurality of data units with a predetermined reproduction time as a unit and recorded, When an uncorrectable error occurs in the header data, there is a problem that muting is applied for the reproduction time of the data unit, causing viewers to feel uncomfortable.

The present invention is intended to solve such a problem, and even if an uncorrectable error occurs in the header data of a unit, the audio and video reproduction states are continuously performed without interposing the muting period. The purpose is to provide a reproducing device that can be secured. It is another object of the present invention to provide a recording medium and a reproducing apparatus therefor capable of reproducing at least only the sound in the unit even if an uncorrectable error occurs in the header data of the unit.

[0007]

According to a first aspect of the present invention, there is provided a reproducing apparatus for compressing audio data in order to achieve the above object.
Data, compressed video data, the compressed audio data, and
Tokoro variable Nagayu knit data and a f <br/> Ddadeta including management information for reproducing the compressed video data into unit
A reproducing device for reproducing in accordance with a constant reproduction time , comprising: storage means for storing the variable length unit data; detection means for detecting whether or not an error has occurred in the header data; If an error in the header data has been detected to have occurred, instead of the compressed audio data and compressed <br/> video data of the variable length unit Todeta containing Ddadeta to this, the the next subsequent variable length unit with Dinner over data It is characterized by further comprising control means for controlling to reproduce the compressed audio data and the compressed video data obtained from the storage means.

In order to achieve the above-mentioned object , the reproducing apparatus of the invention as defined in claim 2 has compressed audio data and compressed image data.
Image data, the compressed audio data and the compressed video data.
And header data including management information for reproducing the over data
Variable Nagayu knit data a predetermined playback time as a unit with
A reproduction apparatus for reproducing a recording medium which is recorded in association with the error in the header data of the variable length uni <br/> Tsu Todeta read from the recording medium to detect whether or not occurred detection means, if the error foremost Ddadeta to the by the detection means is detected to have occurred, and interrupts the reading from the recording medium of the variable length unit Todeta including the header data, the next variable length unit
It is characterized by comprising a control means for performing control so as to resume the data or al read.

In order to achieve the above-mentioned object, the reproducing apparatus according to the third aspect of the invention has compressed audio data and compressed image data.
Image data, the compressed audio data and the compressed video data.
And header data including management information for reproducing the over data
Pairs in a predetermined playback time variable Nagayu knit data units having
A reproduction apparatus for reproducing by response, storage means for storing the variable length unit <br/> Todeta, detecting means for detecting whether an error has occurred in the data in said variable length unit data, If an error in the data in the variable length unit data by said detecting means is detected to have occurred, instead of the compressed audio data and compressed video data of the variable length unit data including the data of the next subsequent variable length < A control means for obtaining unit data from the storage means and performing control so as to reproduce the compressed audio data and the compressed video data is provided.

In order to achieve the above-mentioned object, the reproducing apparatus according to the invention of claim 4 has compressed audio data and compressed image data.
Image data, the compressed audio data and the compressed video data.
And header data including management information for reproducing the over data
Variable Nagayu knit data a predetermined playback time as a unit with
Is a reproducing device for reproducing a recording medium recorded in correspondence with , and detecting for detecting whether or not an error has occurred in the data in the variable-length unit data read from the recording medium. Means, and the variable length unit by the detection means.
If the error foremost data in Tsu bets data is detected to have occurred, and interrupts the reading from the recording medium of the variable length unit data, control to resume reading the next variable length unit data And a control means for performing the above.

[0011]

In the reproducing apparatus according to the first aspect of the present invention, when the detecting means detects that an uncorrectable error has occurred in the header data, instead of reading the audio data and the video data of the unit including the header data. , There is no uncorrectable error in the header data. Since the audio data and the video data of the next and subsequent units are read out from the storage means and reproduced, the muting period is maintained even if an uncorrectable error occurs in the header data of the unit. It is possible to continuously secure the reproduction state of audio and video without being pinched.

In the reproducing apparatus according to the second aspect of the present invention, when the detecting means detects that an uncorrectable error has occurred in the header data, the reading of the unit data including the header data from the recording medium is interrupted. Since the reading is restarted from the next unit data, even if an uncorrectable error occurs in the header data of the unit, the audio and video reproduction states can be continuously secured without interposing the muting period.

In the reproducing apparatus according to the third aspect of the invention, the detection is performed.
An error has occurred in the data in the unit data by means
If this is detected, the audio data of this unit
And instead of reading the video data,
Audio data and video data from the storage means.
Since the data is played back, there is no need to insert a muting period.
It is possible to continuously ensure the playback state of audio and video . In the reproducing apparatus of the invention according to claim 4, the detecting means
Caused an error in the data in the unit data
If this is detected, read this unit data
To resume reading from the next unit data
Voice and voice without interfering with the muting period.
It is possible to continuously secure the video reproduction state .

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall structure of an optical disk reproducing apparatus according to an embodiment of the present invention.

In the figure, 101 is an optical disk. As shown in FIG. 4, for example, the optical disc 101 has data recorded in units of variable-length data units composed of header data, video data, and audio data. Both video data and audio data are M
It may be variable-length data compressed and encoded by the PEG1 system or the like, or video data may be variable-length and audio data may be fixed-length. The header data includes management information necessary for reproducing the compressed data in its own data unit, such as position information of video data and audio data in its own data unit. A pickup 102 irradiates the optical disc 101 with laser light and reads the intensity of the reflected light as a reproduction signal. 103 is waveform equalization for the reproduced signal obtained by the pickup 102,
It is an analog processing system that performs data slicing and the like to generate a data stream composed of, for example, an EFM signal, and also generates a clock for data reproduction. Reference numeral 104 denotes a data processor, which performs synchronization detection and data demodulation (for example, EF) from the data stream obtained by the analog processing system 103.
M demodulation) and error correction processing are performed, and the demodulated data after error correction is output to the system processor 105.
A cache memory 106 temporarily stores each compressed data of video and audio. System processor 10
Reference numeral 5 separates video and audio compressed data from the error-corrected demodulated data sent from the data processor 104 and writes them to the cache memory 106, and reads each video and audio compressed data from the cache memory 106. Then, the data is transferred to the subsequent processing unit. 107
Is a voice processing unit, which decodes the compressed voice data read from the cache memory 106 and supplies a voice signal to the speaker 108. A video processing unit 109 decodes compressed video data read from the cache memory 106 and outputs a video signal to the TV monitor 110.

FIG. 2 is a block diagram showing a detailed configuration of a portion for performing data read / write control on the cache memory 106.

As shown in the figure, the cache memory 106
The storage area is divided into a video cache memory 203 for storing video data and an audio cache memory 204 for storing audio data. Data reading / writing is independently performed on the video cache memory 203 and the audio cache memory 204.
That is, in the configuration of the read / write control system on the video cache side, 205 is the video cache memory 203.
Is a write address counter for generating a write address, and 206 is a read address counter for generating a read address for the video cache memory 203. An address control circuit 207 selectively controls the write address of the write address counter 205 and the read address of the read address counter 206. Reference numeral 208 denotes an error address holding circuit that holds the head memory address to which the video data has been written in the data unit in which the uncorrectable error has occurred in the header data.

The error address held in the error address holding circuit 208 will be supplementarily described. The error correction circuit 210 in the data processor 104 determines whether or not an uncorrectable error has occurred in the header data in the data unit when correcting an error in a certain data unit, and determines that the uncorrectable error has occurred in the header data. If determined, a header error signal is output to the system processor 105. When the system processor 105 inputs the header error signal, it obtains the head memory address to which the video data of the data unit including this header data is written, and holds this write address in the error address holding circuit 208 as an error address. To do.

Reference numeral 209 denotes the error address held in the error address holding circuit 208 and the read address counter 2
This is a comparison circuit for comparing the read address generated with 07. Further, reference numeral 211 is a next address holding circuit for holding the head memory address of the data unit in which the uncorrectable error has occurred in the header data, where the video data of the next data unit is stored.

As described above, the write address counter 205, the read address counter 206, the address control circuit 20.
7, error address holding circuit 208, comparison circuit 209,
The next address holding circuit 211 is also provided commonly to the voice cache memory 204.

Next, a typical operation of this optical disk reproducing apparatus will be described.

First, an analog processing system 103 performs waveform equalization, data slicing, etc. from a reproduced signal obtained by the pickup 102 to generate a data stream, and a data processor 104 demodulates the data stream from this data stream. And error correction processing is performed.
The demodulated data after error correction is the system processor 10
5, the video data is separated into the video data and the audio data, and the video cache memory 203 and the audio cache memory 204 are separated.
Are respectively lighted.

Here, the error correction circuit 210 in the data processor 104 determines whether or not an uncorrectable error has occurred in the header data in the data unit, and when it determines that an uncorrectable error has occurred, it outputs a header error signal. Output to the system processor 105. When the header error signal is input, the system processor 105 obtains the head memory address to which the video data of the data unit including this header part has been written, and sets this write address in the error address holding circuit 208 on the video cache side as an error address. At the same time, the first memory address where the video data of the next data unit is stored is set in the next address holding circuit 211 on the video cache side. Similarly, the system processor 105 obtains the head memory address to which the audio data of the data unit is written, sets this write address in the error address holding circuit 208 on the audio cache side, and holds the next address on the audio cache side. Circuit 2
The head memory address at which the voice data of the next data unit is stored is set to 11.

In parallel with the above operation, the system processor 105 reads each video and audio data from each cache memory 203, 204 and sends each data to the video processing unit 109 and the audio processing unit 107. During this period, the comparison circuits 209 and 209 respectively compare the error address held in the error address holding circuit 208 with the read address generated by the read address counter 206. When the respective addresses match, the system processor 105 updates the value of the read address counter 207 with the address held in the next address holding circuit 211.

As a result, if there is no uncorrectable error in the header data of the next data unit, the video cache memory 203 and the audio cache memory 204.
The video data and the audio data of the next data unit are read from and reproduced respectively. That is, as shown in the operation procedure in FIG. 3, after the read address is updated (step 302), the read address generated by the read address counter 207 is again stored in the error address holding circuit 208 by the comparison circuit 209, and the next error The address is compared (step 301). If the addresses match again in this comparison, it is determined that an uncorrectable error has also occurred in the header data of the next data unit, and the address value of the read address counter 207 is further written with the compressed data of the next data unit. It is updated to the previous start address value. Then, based on the updated address, data is read from the video cache memory 203 and the audio cache memory 204 (step 303), and the video and audio are reproduced.

Thus, according to the optical disk reproducing apparatus of the present embodiment, when an uncorrectable error occurs in the header data of the data unit, instead of reading the video data and the audio data of the data unit from the cache memory, the header data is read. It is possible to read the video / audio data of the next and subsequent data units in which no uncorrectable error exists in the cache memory from the cache memory to ensure the continuity of the video and audio reproduction. Therefore, it is possible to significantly reduce the discomfort to the viewer as compared with the conventional method of muting the sound.

In this embodiment, the read address of the cache memory is updated to ensure the continuity of video and audio reproduction when an uncorrectable error occurs in the header data of the data unit. The same effect can be achieved by using the following method even in an optical disk reproducing device that reproduces each data after video / audio separation without providing a memory.

That is, when it is detected that an uncorrectable error has occurred in the header data, the reading of the data unit containing this header data from the optical disk is interrupted and the reading is restarted from the next data unit. . Then, it is again judged whether or not there is an uncorrectable error in the header data of this unit data, and if there is an uncorrectable error, the same processing is repeated. If there is no uncorrectable error, the audio data and video of the data unit are repeated. Play the data.

The rate of reading data from the disc is
Since the data rate after demodulation is much higher, even if the operation of shifting the read position of the disk is performed as described above, there is no gap in the audio and video.

Next, another embodiment of the present invention will be described.

FIG. 4 is a diagram showing the recording format of the data unit of this embodiment. As shown in the figure, the data unit has fixed-length header data 401 at the head, fixed-length audio data 402, and variable-length video data 403 arranged in order. Both the audio data 402 and the video data 403 are compression coded data. An important point here is that fixed length audio data 402 is directly connected after fixed length header data 401. By using such a recording format, at least the audio data 402 can be reproduced when an uncorrectable error occurs in the header data 401.

That is, even if an uncorrectable error occurs in the header data 401 and the position information of the audio data 402 and the video data 403 recorded in this header data 401 cannot be discriminated, the signal length from the beginning of the data unit is changed. It is possible to count and determine the position where the value exceeds the signal length of the header data 401 as the start address of the audio data 402. Similarly, since the voice data 402 has a fixed length, the position where the signal length counted from the beginning of the data unit reaches the signal length of the header data 401 + the voice data 402 can be determined as the end address of the voice data 402. . Therefore, even if an uncorrectable error occurs in the header data 401 by adding a means for determining the position of the audio data 402 from the data unit and separating the position regardless of the contents of the header data 401, At least only the audio data 402 from the data unit can be correctly separated and written in the cache memory, and the audio can be correctly reproduced.

Further, in a structure having no cache memory, if a means for judging the position of the audio data 402 and separating it by the same method is added, it is possible to detect the occurrence of an uncorrectable error in the header data. By reading only the audio data of the unit including the header data from the optical disc, at least the audio can be correctly reproduced. In this case, the video may be pre-held by the MPEG playback unit.

In this embodiment, the audio data is fixed-length compressed data, but even if the audio data has a variable length, at least only the audio is reproduced when an uncorrectable error occurs in the header data. It is possible to In this case, the determination of the start address of the voice data can be obtained by the method described above. The problem is the end address, but as a countermeasure, for example, record the end address of the audio data at the beginning of the audio data area,
There is a method of determining the end address at the time of decoding and reproducing the audio data area and performing control so as to stop the read from the cache memory at the end address.

[0036]

As described above, according to the present invention, even if an uncorrectable error occurs in the header data of a unit,
It is possible to continuously ensure the reproduction state of the audio and video without interposing the muting period, and it is possible to significantly reduce the discomfort given to the viewer due to the lack of the audio and the video of the unit.

Further, according to the present invention, even if an uncorrectable error occurs in the header data of a unit, at least only the sound in the unit can be correctly reproduced, and good sound reproduction can be ensured.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a detailed configuration of a portion for performing data read / write control on the cache memory in FIG.

FIG. 3 is a flowchart for explaining the operation of the optical disc reproducing apparatus in FIG.

FIG. 4 is a diagram showing a recording format of a data unit according to another embodiment of the present invention.

FIG. 5 is a diagram showing a recording format of conventional variable length data.

FIG. 6 is a diagram showing a data stream in units of data units.

FIG. 7 is a diagram showing a conventional recording format of a data unit.

[Explanation of symbols]

101 ... Optical disc, 102 ... Pickup, 103 ...
Analog processing system, 104 ... Data processor, 105 ...
System processor, 106 ... Cash memory, 107
... audio processing unit, 108 ... speaker, 109 ... video processing unit, 110 ... TV monitor, 203 ... video cache memory, 204 ... audio cache memory, 205 ... write address counter, 206 ... read address counter, 2
07 ... Address control circuit, 208 ... Error address holding circuit, 209 ... Comparison circuit, 211 ... Next address holding circuit.

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Claims (4)

(57) [Claims] 1. Compressed audio data, compressed video data,
Plays back the compressed audio data and the compressed video data.
Variable length and a header data including order management information
A reproduction apparatus for reproducing by the units data units to correspond to a predetermined reproduction time, storage means for storing the variable length unit data, detecting means for detecting whether an error has occurred in Ddadeta to the If an error is detected to have occurred in the header data by the detection means, variable containing Ddadeta to this
-Length unit in place of the compressed audio data and compressed video data Todeta, with the following subsequent variable length unit with Dinner over data from said storage means, the compressed audio data and compressed control means for performing control so as to reproduce the video data A reproducing apparatus comprising: 2. Compressed audio data, compressed video data,
Plays back the compressed audio data and the compressed video data.
Variable length and a header data including order management information
Corresponding to a predetermined reproduction time units data units Zukera
A reproduction apparatus for reproducing the recorded the recording medium is a detecting means for detecting whether an error has occurred in <br/> header data of variable length units Todeta read from the recording medium, If the error foremost Ddadeta to the is detected that generated by the detecting means, before including the header data
Serial variable length unit Todeta said interrupt the reading from the recording medium, reproduction apparatus, characterized by comprising a control means for performing control so as to resume the next variable length units Todeta or al read. 3. Compressed audio data, compressed video data,
Plays back the compressed audio data and the compressed video data.
Variable length and a header data including order management information
A reproduction apparatus for reproducing so as to correspond to a predetermined reproduction time units data in the unit, a storage means for storing the variable length unit data, whether an error has occurred in the data in said variable length unit data When it is detected that an error has occurred in the data in the variable length unit data by the detecting means for detecting and the detecting means, instead of the compressed audio data and the compressed video data of the variable length unit data including the data, to obtain variable length unit data for the next and subsequent from said storage means, the compressed audio data and pressure
A reproducing apparatus comprising: a control unit that controls to reproduce the reduced image data. 4. Compressed audio data, compressed video data,
Plays back the compressed audio data and the compressed video data.
Variable length and a header data including order management information
Corresponding to a predetermined reproduction time units data units Zukera
A reproduction apparatus for reproducing the recorded the recording medium is a detecting means for detecting whether an error has occurred in the data in the variable length unit data read out from said recording medium, by said detecting means If the error foremost data of said variable unit data is detected to have occurred, the accepted
Interrupt the reading from the recording medium-length unit data, reproducing apparatus characterized by comprising a control means for performing control so as to resume the reading of the following variable length unit data.