JP3679333B2 - Disc playback apparatus and playback control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disc playback device for playing back a DVD (Digital Versatile Disk) standard disc, and more particularly to a disc playback device and a playback control method capable of appropriately playing back a disc having a difficult playback location.
[0002]
[Prior art]
In recent years, with the widespread use of DVD software for movies and music, disk playback devices represented by DVD players have become widespread. A DVD standard disc is the same size as a CD (compact disc), but with a narrow track pitch on the recording surface and data is compressed and recorded, 4.7 gigabytes of data can be recorded on one side.
In order to read data from such a DVD standard disk, the disk reproducing apparatus uses a red laser beam having a wavelength shorter than that of the laser beam for CD reading and capable of realizing fine reading, and a reading lens. By increasing the aperture ratio, a smaller spot is connected and high-density reading is possible.
[0003]
An example of the configuration of such a conventional disk reproducing apparatus is shown in FIG. As shown in the figure, the disk reproducing apparatus includes an RF amplifier 101, a servo / driver 102, a signal processing circuit 103, a track buffer 104, a system decoder 105, and a system microcomputer 106, and is based on the DVD standard. The desired data is read from the disk d and reproduced.
[0004]
The RF amplifier 101 generates an RF signal or the like according to the reflected light detection signal from the disk d. The servo / driver 102 reads out data from the disk d by controlling a thread motor, a pickup, and the like.
The signal processing circuit 103 demodulates the read data and performs error correction and the like. The track buffer 104 sequentially stores the demodulated data demodulated by the signal processing circuit 103.
The system decoder 105 decodes the demodulated data stored in the track buffer 104 into video data, audio data, sub-video data, and the like. The system microcomputer 106 controls the entire disk playback device.
[0005]
Note that a plurality of different data such as video, audio, and sub-picture (sub-picture) are recorded on the disk d by various compression methods. Then, the user can operate the disc playback device to play back these data recorded on the disc d in accordance with a prescribed playback order, or to play back by selecting an arbitrary playback order.
For example, when one video stream, a maximum of eight audio streams, and a maximum of 32 sub-video streams are recorded on the disk d, the user can add one audio stream and one video stream in addition to one video stream. A sub-picture stream can be arbitrarily selected, and data can be reproduced in a desired reproduction order by a disc reproduction apparatus.
[0006]
At this time, the disc playback apparatus not only continuously plays back the data recorded on the disc d, but also according to playback management information (navigation data) that defines how to play back the recorded data. Data to be read are sequentially read and demodulated.
More specifically, as shown in FIG. 6, the system microcomputer 106 determines the reproduction order (navigation) according to the navigation data (A1), and sets an address on the disk for reading the data (A2).
When the servo / driver 102 is controlled and data is searched and read according to the set address, the system microcomputer 106 controls the signal processing circuit 103 to perform demodulation and error correction of the read data (A3), The demodulated data is stored in the track buffer 104 (A4). The system microcomputer 106 repeats the operations A1 to A4.
In parallel, the system microcomputer 106 controls the system decoder 105 to continuously decode the demodulated data stored in the track buffer 104 (A5).
[0007]
As described above, the disk reproducing apparatus accumulates demodulated data of a predetermined capacity in the track buffer 104 by repeating operations such as data reading, demodulation and error correction. Then, by continuously decoding the demodulated data with the system decoder 105, it is possible to continuously reproduce video and the like without a sense of incongruity.
[0008]
[Problems to be solved by the invention]
However, the conventional disk reproducing apparatus described above performs demodulation and error correction of the read data if the disk d to be reproduced is an object that is partially scratched or has a manufacturing defect. In some cases, the signal processing circuit 103 cannot perform error correction completely.
In such a case, the system decoder 105 decodes the demodulated data that has not been completely corrected, and generates inappropriate video data, audio data, and the like.
In other words, if there is a hard-to-reproduce location on the disk d, error correction cannot be performed completely when demodulating the data at the location on the disc playback device, so block noise or the like is output to the decoded video. Will end up.
Further, when data that cannot be corrected by the signal processing circuit 103 is demodulated, the system decoder 105 cannot perform decoding and may hang up. In this case, since the playback operation is interrupted in the disk playback device, the user cannot view the video and audio after that point.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disc playback apparatus and playback control method capable of appropriately playing back a disc having a difficult-to-play location.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a disc player according to the first aspect of the present invention provides:
Setting means for setting an address on the disk of target data to be read; and
Searching the address set by the setting means, reading means for reading the target data from the disk,
Demodulation means for demodulating the data read by the reading means and performing error correction;
An acquisition means for acquiring a jitter value of a reproduction signal when error correction cannot be completely performed when the demodulation means demodulates data;
When the jitter value acquired by the acquiring unit exceeds a predetermined value, the data read by the reading unit is discarded and the reading unit is controlled to search for the next target data. Reading control means;
It is characterized by providing.
[0011]
According to the present invention, the setting means sets the address on the disk of the target data to be read, for example, according to the reproduction management information. The reading means searches the address set by the setting means and reads the target data from the disk. The demodulating means demodulates the data read by the reading means and performs error correction. The acquisition unit acquires the jitter value of the reproduction signal when error correction cannot be completely performed when the demodulation unit demodulates the data. When the jitter value acquired by the acquisition unit exceeds a predetermined value, the read control unit discards the data read by the read unit and controls the read unit, for example, several seconds later. Search the target data. As described above, when error correction cannot be performed completely and it is determined that the cause is a partial scratch or a manufacturing defect caused on the disc according to the jitter value, the next data is searched and read. For this reason, data that cannot be completely corrected at the time of demodulation is discarded and the next program is set, so that block noise or the like is not output to the decoded video. As a result, it is possible to appropriately reproduce a disc having a portion that is difficult to reproduce.
[0012]
In order to achieve the above object, a disc player according to the second aspect of the present invention provides:
Setting means for setting an address on a disc of target data to be read according to predetermined reproduction management information;
Searching for an address set by the setting means, and reading means for reading the target data from the disk by the obtained reproduction signal;
Demodulation means for demodulating the data read by the reading means and performing error correction;
An acquisition means for acquiring a jitter value of a reproduction signal when error correction cannot be completely performed when the demodulation means demodulates data;
Discriminating means for discriminating whether or not the jitter value acquired by the acquiring means exceeds a predetermined specified value;
Read control means for discarding the data read by the read means and controlling the read means to search for the next target data when it is determined by the determination means that the jitter value exceeds a prescribed value When,
It is characterized by providing.
[0013]
According to the present invention, the setting means sets the address on the disk of the target data (VOBU) to be read according to the reproduction management information such as NV_Pack. The reading means searches for the address set by the setting means, and reads the target data from the disk by the acquired reproduction signal. The demodulating means demodulates the data read by the reading means and performs error correction. The acquisition unit acquires the jitter value of the reproduction signal when error correction cannot be completely performed when the demodulation unit demodulates the data. The discriminating unit discriminates whether or not the jitter value acquired by the acquiring unit exceeds a predetermined value. The reading control unit discards the data read by the reading unit when the determining unit determines that the jitter value exceeds the specified value, and controls the reading unit to, for example, target data after several seconds. Search for. As described above, when error correction cannot be performed completely and it is determined that the cause is a partial scratch or a manufacturing defect caused on the disc according to the jitter value, the next data is searched and read. For this reason, data that cannot be completely corrected at the time of demodulation is discarded and the next program is set, so that block noise or the like is not output to the decoded video. As a result, it is possible to appropriately reproduce a disc having a portion that is difficult to reproduce.
[0014]
The disc reproducing apparatus includes display means for displaying predetermined display information;
Display information generating means for generating display information indicating that data cannot be reproduced continuously due to a disc failure when the demodulating means cannot perform error correction completely, and displaying the display information on the display means; May be.
[0015]
In order to achieve the above object, a playback control method according to a third aspect of the present invention is:
A setting step for setting an address on a disc of target data to be read according to predetermined reproduction management information;
Searching the address set in the setting step, and reading the target data from the disk by the acquired reproduction signal;
Demodulating the data read in the reading step and performing error correction;
In the demodulation step, if error correction cannot be completely performed when demodulating data, an acquisition step of acquiring a jitter value of a reproduction signal;
A determination step of determining whether or not the jitter value acquired in the acquisition step exceeds a predetermined value;
A reading control step of discarding the data read in the reading step and searching for the next target data in the reading step when it is determined in the determining step that the jitter value exceeds a specified value When,
It is characterized by providing.
[0016]
According to the present invention, the setting step sets the address on the disk of the target data (VOBU) to be read according to the reproduction management information such as NV_Pack. In the reading step, the address set in the setting step is searched, and the target data is read from the disk by the acquired reproduction signal. In the demodulation step, the data read in the reading step is demodulated and error correction is performed. The acquisition step acquires the jitter value of the reproduction signal when error correction cannot be completely performed when demodulating the data in the demodulation step. In the determination step, it is determined whether or not the jitter value acquired in the acquisition step exceeds a predetermined value. The read control step discards the data read in the read step when it is determined in the determination step that the jitter value exceeds the specified value. Search. As described above, when error correction cannot be performed completely and it is determined that the cause is a partial scratch or a manufacturing defect caused on the disc according to the jitter value, the next data is searched and read. For this reason, data that cannot be completely corrected at the time of demodulation is discarded and the next program is set, so that block noise or the like is not output to the decoded video. As a result, it is possible to appropriately reproduce a disc having a portion that is difficult to reproduce.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
A disk playback apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
[0018]
FIG. 1 is a block diagram showing an example of the configuration of a disc playback apparatus applied to an embodiment of the present invention. As shown in the figure, the disk reproducing apparatus includes a pickup 1, an RF amplifier 2, a motor 3, a servo circuit 4, a signal processing circuit 5, a track buffer 6, a system decoder 7, a system microcomputer 8, and a display. Part 9.
In addition, this disk reproducing | regenerating apparatus reproduces | regenerates the data recorded on the disk d of DVD (Digital Versatile Disk) specification as an example.
[0019]
In the DVD standard, main video data, sub-video data, audio data, and the like are managed in units of VOBS (video object set). This VOBS is, for example, an information unit for one movie.
A VOBS is composed of a plurality of VOBs (video objects), and each VOB is composed of a plurality of cells (cells).
This Cell is an information unit for one scene or one cut in a movie, for example. In the DVD standard, a movie or the like has a function such as a multi-story in which a story branches into a plurality, and such a function is realized by a combination of the cells.
[0020]
Further, each cell is composed of a plurality of VOBUs (video object units) as shown in FIG.
This VOBU is information in units of a playback time of 0.4 to 1.0 seconds, and includes NV_Pack (navigation pack), V_Pack (video pack), A_Pack (audio pack), and SP_Pack (sub-video pack). It is composed of aggregates.
NV_Pack is reproduction management information, and is information that specifically defines how data in the VOBU is reproduced.
V_Pack, A_Pack, and SP_Pack are entity data of video, audio, and sub-video, respectively.
[0021]
Returning to FIG. 1, the pickup 1 irradiates laser light having a predetermined wavelength toward the recording surface of the disk d, receives the reflected light, and converts it into an electrical signal (reflected light detection signal). The pickup 1 supplies this reflected light detection signal to the RF amplifier 2.
The pickup 1 is supported by a predetermined guide shaft or the like so as to be movable in the radial direction of the disk d so that target data can be read out from the disk d as appropriate.
[0022]
The RF amplifier 2 generates an RF signal, a tracking signal, a focus signal, and the like from the reflected light detection signal supplied from the pickup 1. Further, a binary signal obtained by data slicing the RF signal is generated.
The RF amplifier 2 supplies the generated tracking signal or the like to the servo circuit 4 and supplies the generated binarized signal to the signal processing circuit 5 as a reproduction signal.
The RF amplifier 2 measures the jitter of the binarized signal (reproduced signal) and generates a voltage signal (jitter value signal) corresponding to the measured jitter. Specifically, the RF amplifier 2 measures the jitter of the binarized signal from the phase error between the generated binarized signal and the recovered clock obtained by the PLL (Phase Locked Loop) operation using the binarized signal as an input. A jitter value signal indicating the measured jitter value is generated.
The RF amplifier 2 supplies the generated jitter value signal to the system microcomputer 8.
[0023]
The motor 3 includes a spindle motor for rotating a predetermined turntable on which the disk d is mounted. The motor 3 is controlled by the servo circuit 4 and rotates the disk d so that the linear velocity is constant, for example.
[0024]
The servo circuit 4 controls the drive of the motor 3 and rotates it at a predetermined rotational speed. In addition, the servo circuit 4 drives and controls a thread motor (not shown) by a tracking signal supplied from the RF amplifier 2 and appropriately moves the pickup 1 in the radial direction of the disk d.
[0025]
The signal processing circuit 5 demodulates the reproduction signal supplied from the RF amplifier 2 and performs error correction. The signal processing circuit 5 sequentially supplies the demodulated data obtained by this demodulation or the like to the track buffer 6.
By the way, if the disk d to be reproduced is an object that is partially scratched or has a manufacturing defect, the signal processing circuit 5 completely performs error correction when demodulating the reproduction signal. It may not be possible.
In this case, the signal processing circuit 5 generates demodulation error information indicating that the error correction cannot be completely performed, and supplies the demodulation error information to the system microcomputer 8.
[0026]
The track buffer 6 includes a RAM (Random Access Memory) having a predetermined capacity, and sequentially stores the demodulated data supplied from the signal processing circuit 5.
The demodulated data stored in the track buffer 6 is sequentially supplied to the system decoder 7.
[0027]
The system decoder 7 decodes the demodulated data supplied from the track buffer 6 and generates video data, audio data, and the like.
The system decoder 7 supplies the generated video data and audio data to a predetermined AV amplifier or the like.
[0028]
The system microcomputer 8 includes, for example, a one-chip microcomputer provided with a ROM (Read Only Memory), a RAM, and a CPU (Central Processing Unit), and controls the entire disk reproducing apparatus.
The system microcomputer 8 controls the servo circuit 4 and the like to acquire unique information that defines the reproduction order of the target data called PGCI (program chain information) recorded in advance on the disk d and stores it in its own RAM or the like To do. And the PGC operation | movement which reads the object Cell (object data, such as an image | video) according to memorize | stored PGCI is performed.
[0029]
Specifically, when executing the PGC operation, the system microcomputer 8 acquires NV_Pack that is the playback management information of the above-described VOBU constituting the Cell, and plays back the target data (VOBU) from the disk d according to the NV_Pack. .
That is, when acquiring the NV_Pack, the system microcomputer 8 sets the address of the target data to be read, controls the servo circuit 4 and the like, and searches for the target data of the set address. The searched target data is read from the disk d, the signal processing circuit 5 is controlled, the read target data (reproduced signal) is demodulated, error-corrected, etc., and the demodulated data is stored in the track buffer 6.
The system microcomputer 8 repeatedly performs a series of operations including address setting, search, reading, demodulation / error correction, data storage, and the like according to the free capacity of the track buffer 6 and the like.
[0030]
In parallel with these operations, the system microcomputer 8 controls the system decoder 7 to decode the demodulated data stored in the track buffer 6 and sequentially generate video data, audio data, and the like.
[0031]
When the demodulation error information is supplied from the signal processing circuit 5, the system microcomputer 8 acquires the jitter value signal supplied from the RF amplifier 2, and determines whether or not the current jitter value is within a specified value. To do.
If the system microcomputer 8 determines that the jitter value is not within the specified value (exceeds the specified value), the error cannot be completely corrected due to partial scratches on the disk d or manufacturing problems. The next program (for example, the next NV_Pack or target data to be reproduced several seconds later) is set and a new search is performed.
[0032]
The display unit 9 is composed of an LCD (Liquid Crystal Display) panel or the like, and displays the operation status and the like of the disk playback device. For example, when the signal processing circuit 5 cannot perform error correction completely, the display unit 9 displays a message such as “Some parts cannot be read. Continuous video and audio cannot be output.”
[0033]
The operation of the disk reproducing apparatus according to the embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a flowchart for explaining the reproduction control process executed by the system microcomputer 8. This reproduction control process is started after a reproduction start is instructed via an operation unit (not shown) in a state where PGCI (program chain information) is read from the reproduction target disk d.
[0034]
The system microcomputer 8 acquires NV_Pack, which is playback management information of the VOBU constituting the target Cell, according to PGCI, and sets an address on the disk from this NV_pack (Step S11). That is, the system microcomputer 8 sets the address of the target data (VOBU) to be read according to NV_Pack.
[0035]
The system microcomputer 8 controls the servo circuit 4 and the like and searches for target data (VOBU) based on the set address (step S12).
The system microcomputer 8 controls the signal processing circuit 5 to perform data demodulation and error correction (step S13). That is, when reading the target data at the set address, the system microcomputer 8 controls the signal processing circuit 5, demodulates the read target data (reproduced signal), and performs error correction and the like.
[0036]
The system microcomputer 8 determines whether the correction is completed (step S14). The system microcomputer 8 determines whether or not error correction has been completed based on whether or not demodulation error information has been supplied from the signal processing circuit 5. That is, when the demodulation error information is supplied from the signal processing circuit 5, the system microcomputer 8 determines that error correction has not been performed completely.
[0037]
If the system microcomputer 8 determines that the correction has been completed, the system microcomputer 8 advances the processing to step S22 described later. On the other hand, when determining that the correction is not completed, the system microcomputer 8 acquires a jitter value from the RF amplifier 2 (step S15). That is, the system microcomputer 8 acquires a jitter value signal supplied from the RF amplifier 2 when error correction is not completely performed by the signal processing circuit 5.
[0038]
The system microcomputer 8 determines whether or not the acquired jitter value is within a specified value (step S16). For example, the system microcomputer 8 determines whether or not the acquired jitter value is within 8% defined in the DVD standard. The specified value of the jitter value may be determined from the error correction capability of the signal processing circuit 5 or the like.
[0039]
If the system microcomputer 8 determines that the jitter value is not within the specified value (exceeds the specified value), the system microcomputer 8 advances the process to step S19 described later. On the other hand, when it is determined that the jitter value is within the specified value, the system microcomputer 8 searches the target address data again and controls the signal processing circuit 5 to demodulate the read target data (reproduced signal). Then, error correction or the like is performed (step S17).
[0040]
The system microcomputer 8 determines whether or not the correction is completed (step S18). If it is determined that the correction has not been completed (and it is determined in step S16 that the jitter value is not within the specified value), the read data is discarded (step S19). That is, the system microcomputer 8 discards the demodulated data without storing it in the track buffer 6 because the error correction cannot be completely performed due to a partial damage or manufacturing defect in the disk d.
[0041]
The system microcomputer 8 displays a predetermined message on the display unit 9 indicating that data cannot be reproduced continuously due to a defect in the disk d (step S20). For example, the system microcomputer 8 generates a message such as “There is a part that cannot be read. Continuous video and audio cannot be output” and displays the message on the display unit 9.
[0042]
Further, when the demodulated data is discarded, the system microcomputer 8 sets the next program (step S21).
Note that the next program is specifically the next NV_Pack or the target data to be reproduced several seconds after the target data that cannot be read as shown in FIG. 4 (however, in reverse playback, It becomes the target data to be played back a few seconds ago).
If it is difficult to perform an accurate search within the range specified by VOBU_SRI (VOBU / search information) in DSI (data search information) included in NV_Pack (time interval between VOBUs, etc.) It becomes a number (for example, chapter).
[0043]
Returning to FIG. 3, when it is determined in step S18 (or step S14) that the correction has been completed, the system microcomputer 8 obtains the demodulated data obtained by demodulation or the like (the demodulated data in which error correction has been completely performed). ) Is stored in the track buffer 6 (step S22).
[0044]
The system microcomputer 8 controls the system decoder 7 to perform decoding (step S23). That is, the system microcomputer 8 decodes the demodulated data stored in the track buffer 6 to generate video data, audio data, and the like.
The system decoder 7 supplies the decoded video data and audio data to an AV amplifier (not shown).
[0045]
As described above, when demodulation error information is supplied from the signal processing circuit 5 by the reproduction control process, the system microcomputer 8 acquires the jitter value signal supplied from the RF amplifier 2 and the current jitter value is within a specified value. It is determined whether or not. If it is determined that the jitter value exceeds the specified value, the reason why the error correction cannot be completely performed is caused by a partial scratch or a manufacturing defect in the disk d. Set a program and perform a new search.
For this reason, data that cannot be completely corrected at the time of demodulation is discarded and the next program is set, so that block noise or the like is not output to the decoded video. Then, according to the jitter value, it is possible to appropriately determine whether or not the cause of the error correction cannot be completely performed is a defect (scratch or the like) inherent to the disk.
As a result, it is possible to appropriately reproduce a disc having a portion that is difficult to reproduce.
[0046]
Further, when error correction cannot be performed completely, the system microcomputer 8 displays a predetermined message on the display unit 9, so that the user can be informed that continuous reproduction cannot be performed due to a problem with the disk d. .
[0047]
In the above embodiment, the playback control process in the PGC operation according to the PGCI has been described. However, the playback control process is appropriately applied to operations other than the PGC operation, for example, a playback operation according to an arbitrary playback order selected by the user. Is possible.
[0048]
In the above embodiment, the disk reproducing apparatus for reproducing the DVD standard disk d has been described. However, the recording medium to be reproduced by the disk reproducing apparatus is arbitrary.
For example, the disc playback apparatus may play a disc such as a CD, MD, or MO in addition to the recording medium to be played back.
[0049]
【The invention's effect】
As described above, according to the present invention, it is possible to appropriately reproduce a disc having a portion that is difficult to reproduce.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of the configuration of a disc playback apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing an example of information such as VOBU recorded on a disc.
FIG. 3 is a flowchart for explaining a reproduction control process according to the embodiment of the present invention.
FIG. 4 is a schematic diagram for explaining a next program to be set.
FIG. 5 is a block diagram showing an example of a configuration of a conventional disk reproducing device.
FIG. 6 is a schematic diagram for explaining the operation of a conventional disk reproducing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pickup 2 RF amplifier 3 Motor 4 Servo circuit 5 Signal processing circuit 6 Track buffer 7 System decoder 8 System microcomputer 9 Display part

Claims (4)

Setting means for setting an address on the disk of target data to be read; and
Searching the address set by the setting means, reading means for reading the target data from the disk,
Demodulating means for demodulating data read by the reading means and performing error correction;
An acquisition means for acquiring a jitter value of a reproduction signal when error correction cannot be completely performed when the demodulation means demodulates data;
When the jitter value acquired by the acquiring unit exceeds a predetermined value, the data read by the reading unit is discarded and the reading unit is controlled to search for the next target data. Reading control means;
A disc playback apparatus comprising: Setting means for setting an address on a disc of target data to be read according to predetermined reproduction management information;
Searching for an address set by the setting means, and reading means for reading the target data from the disk by the obtained reproduction signal;
Demodulating means for demodulating data read by the reading means and performing error correction;
An acquisition means for acquiring a jitter value of a reproduction signal when error correction cannot be completely performed when the demodulation means demodulates data;
Discriminating means for discriminating whether or not the jitter value acquired by the acquiring means exceeds a predetermined specified value;
Read control means for discarding the data read by the reading means and controlling the reading means to search for the next target data when the determining means determines that the jitter value exceeds a prescribed value When,
A disc playback apparatus comprising: Display means for displaying predetermined display information;
Display information generating means for generating display information indicating that data cannot be reproduced continuously due to a disc failure when the demodulating means cannot perform error correction completely, and displaying the display information on the display means; ,
The disc reproducing apparatus according to claim 1 or 2, A setting step for setting an address on a disc of target data to be read according to predetermined reproduction management information;
Searching the address set in the setting step, and reading the target data from the disk by the acquired reproduction signal;
Demodulating the data read in the reading step and performing error correction;
In the demodulation step, when error correction cannot be completely performed when demodulating data, an acquisition step of acquiring a jitter value of a reproduction signal;
A determination step of determining whether or not the jitter value acquired in the acquisition step exceeds a predetermined value;
A reading control step for discarding the data read in the reading step and searching for the next target data in the reading step when it is determined in the determining step that the jitter value exceeds a specified value When,
A reproduction control method comprising:

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