JP3890871B2 - Apparatus and method for reproducing digital video signal or audio signal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a playback apparatus recorded on a medium such as an optical storage medium, and more particularly to a technique that enables copyright protection of a signal recorded on a medium.
[0002]
[Prior art]
A DVD that records an AV signal compressed using MPEG2 has a problem that the AV signal can be copied without deterioration of quality because the AV signal is handled as digital data.
[0003]
In response to this, as described in Nikkei Electronics (1997.2.24 99p-123P), the introduction of digital watermarking technology that superimposes information such as permission, prohibition, and permission for only one generation for copying so that it cannot be detected by the user. Has been. The above technique describes a method of performing copy prevention processing on an analog output in accordance with a detected signal.
[0004]
[Problems to be solved by the invention]
However, if there is a medium that permits copying only once for broadcasting, etc., it is copied to a pirated disc copied from a DVD-R disc to a DVD-ROM after being copied to a DVD-R disc (recordable once). However, no consideration is given to copyright protection by restricting the playback of each user's player.
[0005]
If copying is permitted only once for broadcasting, etc., it is recorded on a DVD-R disc (recordable once), a DVD-RAM disc (rewritable), etc., and then copied illegally to a DVD-ROM. In contrast to the pirated discs, the reproduction of the DVD-ROM / R / RAM discs possessed by general users on a player capable of reproducing them is stopped. Another object is to construct a means for correctly reporting the cause of playback stop to the user when playback is prohibited.
[0006]
Further, in order to control whether copying is permitted or prohibited, the operation of a system having a function of detecting data embedded by the digital watermark technology is not described in the above-mentioned conventional technology. It also does not describe the configuration of a system that has a function to detect data.
[0007]
When the function of detecting the embedded data is configured with hardware, the circuit scale varies greatly depending on the configuration. Therefore, building an appropriate system becomes an issue. Another problem is to reliably detect embedded data for controlling copying permission / prohibition without easily tampering with the function of detecting the embedded data using the digital watermark technique.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an error correcting error in video data or audio data generated by superimposing a digital video information or audio signal on copying permission information as a digital watermark. A playback device for playing back video data or audio data from a read-only medium or recordable medium, to which a correction code is added and modulated according to a modulation rule suitable for the recording medium, and the playback medium is read-only Means for determining whether the medium is a medium ; demodulating means for demodulating the modulated data in accordance with the modulation rule; temporary storage means for holding demodulated data demodulated by the demodulating means; and the temporary storage means Error correction means for performing error correction processing on the demodulated data stored in the error correction code, and the temporary storage means From the error correction processed data, and means for reproducing the information on permission of copying superposed as electronic watermark information on permission of the copying is permitted once copied, the medium to be reproduced with a reproduction-only medium when the determination, the data information relating to permission of the copying is already playing process, the above problem is achieved by an output control means for outputting stopping process, the video data or audio data reproducing apparatus comprising a.
[0009]
Further, the above-mentioned problem is achieved by integrating the means for reproducing information relating to the permission of copying, the demodulating means, the error correcting means, and the RAM into a single semiconductor device.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a block diagram of a DVD playback apparatus according to an embodiment of the present invention. Reference numeral 101 denotes a DVD-ROM disc, DVD-R disc, or DVD-RAM disc on which video data or the like is recorded. In the present embodiment, video data or audio data on which duplication permission information is superimposed is recorded on each disc, and the duplication permission information that is superimposed is the original video data. Alternatively, it is assumed that the quality of the audio data cannot be changed without significantly degrading, and that the disc identification code (a code that can be used to identify whether the disc is a reproduction-only disc) is further added to the video data or audio data. .
[0012]
102 is an optical pickup that detects a signal from the disk 101, 103 is a preamplifier that performs amplification, waveform equalization, etc. on the signal detected by the optical pickup, and 104 reproduces data modulated according to a modulation rule suitable for the recording medium. Demodulating means for binarizing the signal and performing bit synchronization and demodulation; 105, a RAM in which demodulated reproduction data is temporarily stored; 106, data to which an error correction code demodulated and stored in the RAM 105 is added Error correction means for performing error correction processing on the image, 107 is means for detecting the disc identification code recorded on the disc together with the video data, 108 is means for detecting the duplication permission information superimposed from the video data, 109 is a means for generating a disc reproduction stop signal 114 from the detected identification code and the duplication permission information. Error correction means 106 if the disc playback stop signal 114 is generated, and at the same time destroy the reverse without correcting the data, generates an uncorrectable flag 118.
[0013]
110 is message information generating means for generating video data (characters, illustrations, etc.) or an audio signal indicating that reproduction is impossible, 111 is corrected data stored in 105 or message information from 110 according to the disc reproduction stop signal. 112 is an output control means for performing timing control for outputting data from the selection circuit 111, and 113 is a data output terminal.
[0014]
Of course, if the copy is not prohibited, it is not necessary to stop the output, so that the reproduction data is sent to the output control means 112 and output while adjusting the output transfer format and controlling the timing. For example, when the data output terminal 113 is connected to a PC, a bus such as SCSI, ATAPI, IEEE1394, or USB can be considered.
[0015]
Reference numeral 115 denotes an interface with a microcomputer, and reference numeral 121 denotes a microcontroller that controls a signal processing 120 composed of the elements 104, 105, 106, 107, 108, 109, 110, 111, 112, and 115.
[0016]
Disc playback with this DVD playback device will be described below.
[0017]
The signal recorded on the disk 101 is converted into an electric signal by the pickup 102, amplified by the preamplifier 103 and subjected to waveform equalization, and then modulated and recorded by the demodulating means 104 according to a modulation rule suitable for the recording medium. The binarized signal, bit synchronization, and demodulation of the reproduced data are performed. The demodulated reproduction data is temporarily stored in the RAM 105. For the stored data, the error correction means 106 performs error correction processing on the reproduced data to which an error correction code for error correction is added. The corrected reproduction data is sent to the duplication permission information detecting means 108. The copy permission information detecting unit 108 detects the copy permission information superimposed from the reproduction data.
[0018]
The copy permission information indicates which type of data the recorded data is as follows. 1) Duplication permitted 2) Duplication prohibited 3) Only one generation permitted to be copied The detected information is sent to the disc reproduction prohibition signal generating means 109. The disc identification code detection means 107 detects the disc identification code added to the video data or audio data, and sends the result to the disc reproduction stop signal generation means 109. The disc identification code identifies 1) a read-only disc and 2) a recordable disc.
[0019]
The disc reproduction prohibition signal generation unit 109 activates the disc reproduction stop signal 114 when the duplication permission information is permitted for duplication for only one generation and the disc identification code is determined to be a reproduction-only disc. When the disk reproduction stop signal 114 becomes active, the error correction means 106 destroys the reproduction data stored in the RAM and sends a flag indicating that data correction is impossible to the microcontroller 115.
[0020]
When the disc playback stop signal 114 becomes active, the message information generating means 110 generates video or audio message data indicating that playback has been stopped due to a violation of copying permission. The message information may include a contact information (phone number, address, etc.) of a copyright management organization. The message information may be generated by a ROM that stores the generated data. The selection circuit 111 normally selects the reproduction data read from the RAM, and selects the message information from the message information generation means 110 when the disk reproduction stop signal 114 is active.
[0021]
As described above, according to the present embodiment, a video signal or audio signal for which only one generation from broadcasting is permitted is recorded on a DVD-RAM or DVD-R, and then recorded on a DVD-ROM based on the DVD-R or DVD-RAM. Playback of duplicate pirated discs can be prohibited.
[0022]
Also, by outputting a message signal, the user can recognize that it is due to a copyright problem, not a failure of the playback device or a scratch on the disc. Also, by displaying the contact information to the copyright management organization, it is possible to collect information from the user for identifying the pirated creator.
[0023]
In addition, when the signal processing 120 is a single semiconductor chip, data destruction is also performed in the case of a copyright violation. Therefore, even if the microcontroller software is altered and the uncorrectable flag is ignored, The data is corrupted and cannot be read.
[0024]
Therefore, the condition for activating the disc playback stop signal 114 in the disc playback stop signal generation means 109 is determined when the copy permission information is permitted to be copied for only one generation and the disc identification code is a playback-only disc, or the copy permission If it is determined that the information is copy-prohibited and the identification code is a recordable disc, reproduction of a DVD-R / RAM in which the copy-prohibited disc is illegally recorded can also be prevented. Therefore, according to this embodiment, it is possible to provide a reproducing apparatus that can sufficiently protect the copyright.
[0025]
Thus, the detection by the duplication permission information detection means 108 is performed between the demodulation means 104 and the error correction means 106 and the output control means 112, that is, a reproduction signal suitable for detecting the duplication permission control information is duplicated. The license information detection means 108 receives and performs detection processing, and the output control means 112 performs output control according to the result of the detection processing, so that the RAM 105 can be used for the processing of each means for reproduction. Can be reduced.
[0026]
Further, as is clear from FIG. 1, the signal processing 120 can be made difficult to tamper with, if such a single LSI is configured so as not to be corrected internally.
[0027]
Here, in the case of a system that does not have an MPEG decoder, such as the system shown in FIG. 1, the signal processing 120 outputs data after error correction. Further, the signal processing 120 is not shown in FIG. 1, but in the case of a system in which the recorded data is image data compressed by MPEG and includes an MPEG decoder, not only demodulation and error correction, but also MPEG Outputs the decoded (decompressed) data.
[0028]
Regardless of whether the system includes an MPEG decoder or not, it is possible to prevent the system from being tampered with if it is configured with a single LSI.
[0029]
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram of a DVD reproducing apparatus according to the second embodiment.
[0030]
The disc 101 to be played back in this embodiment is intended for DVD-ROM, DVD-R, or DVD-RAM, of which DVD-RAM / R has wobbling grooves. Therefore, the push-pull signal for tracking is modulated by wobble. This wobble is necessary for tracking at the time of recording, and does not exist on a read-only disk.
[0031]
This embodiment is the same as the first embodiment except for the following three points. 1) The wobble detection means 116 is provided. 2) A push-pull signal terminal is provided in the preamplifier 103 and connected to the wobble detection means 116. 3) The disc playback stop signal stop unit 109 determines that the wobble detection unit 116 determines that there is no wobble, or the disc identification code detection unit 107 determines that the disc is a reproduction-only disc. The disc playback stop signal is activated when it is determined.
[0032]
In the present embodiment, the wobble is detected by the wobble detection means 116 simultaneously with the reproduction of data as in the first embodiment. The disc playback stop signal stop unit 109 is determined as a playback-only disc by either the wobble detection unit 116 or the disc identification code detection unit 107, and at the same time, when the copy permission information detection unit 108 determines that one-generation copy is permitted, Activate the disc playback stop signal. Therefore, even if the disc identification code is rewritten, reproduction is surely prohibited.
[0033]
As described above, according to the present embodiment, a video signal or audio signal for which only one generation from broadcasting is permitted is recorded on a DVD-RAM or DVD-R, and then recorded on a DVD-ROM based on the DVD-R or DVD-RAM. Playback of duplicate pirated discs can be prohibited. In this embodiment, the condition that the disc is a read-only disc is set so that either the wobble is not present or the identification code is a read-only disc, so that the pirated version is surely detected. Even if the disc is excluded from the determination conditions, the same effect as in the first embodiment can be obtained.
[0034]
Further, as in the first embodiment, the RAM 105 can be shared by the processing of each means for reproduction, and the circuit scale can be reduced. If the signal processing 120 has a configuration in which it is difficult to modify the inside as one LSI, tampering can be made difficult.
[0035]
Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a block diagram of a DVD reproducing apparatus according to the third embodiment.
[0036]
This embodiment is the same as the first embodiment except for the following three points. 1) A reflectance identification circuit 117 is provided. 2) A point that outputs information on the reflectance of the preamplifier 103 is provided and connected to the reflectance identification circuit 117. 3) The disc reproduction stop signal stop unit 109 is determined to be a reproduction-only disc by any one of the reflectance identification unit 117, the wobble detection unit 116, and the disc identification code detection unit 107, and at the same time, the copy permission information detection unit 108 performs one generation duplication. The disc playback stop signal is activated when it is determined to be permitted.
[0037]
In the present embodiment, as in the second embodiment, data is reproduced, and at the same time, reflectance information is sent from the preamplifier 103 to the reflectance detection means 117, and the reflectance identification means sets a threshold value for the magnitude of the reflectance. Discs above the threshold are identified as read-only discs. The disc reproduction stop signal stop unit 109 is determined as a reproduction-only disc by any one of the reflectance identification unit 117, the wobble detection unit 116, and the disc identification code detection unit 107, and at the same time, the first generation duplication is permitted by the duplication permission information detection unit 108. When it is determined that the disc playback stop signal is active.
[0038]
Therefore, even if the disc identification code is rewritten, reproduction is surely prohibited. In this embodiment, the condition of being a read-only disk is set to reflectivity, presence / absence of wobble, and identification code is a read-only disk, so that pirated versions are reliably detected. The condition for determining a disk is any one of the three conditions as a determination condition, and the two conditions are satisfied at the same time. If any one of the three conditions is a determination condition, or any one is satisfied, or one condition The same effect as in the first embodiment can be obtained even when the above is used as the determination condition.
[0039]
Further, as in the first embodiment, the RAM 105 can be shared by the processing of each means for reproduction, and the circuit scale can be reduced. If the signal processing 120 has a configuration in which it is difficult to modify the inside as one LSI, tampering can be made difficult.
[0040]
Next, a fourth embodiment of the present invention will be described with reference to the drawings.
FIG. 4 is a block diagram of a DVD reproducing apparatus according to the fourth embodiment.
[0041]
In this embodiment, instead of outputting the output of the message information generation means 110 to the selection circuit 111 and inputting the output of the selection circuit 111 to the output control means 112, the output of the message information generation means 110 is sent to the RAM 105 through the RAM write controller 119. Except for the point of writing to, this is common with the third embodiment. In this embodiment, when the disc reproduction stop signal 114 becomes active, the video data or audio data to be output is overwritten on the original, so that the output of the message information generating means 110 is output as in the second embodiment. The same effect can be obtained by outputting to the selection circuit 111 and inputting the output of the selection circuit 111 to the output control means 112.
[0042]
Further, as in the first embodiment, the RAM 105 can be shared by the processing of each means for reproduction, and the circuit scale can be reduced. If the signal processing 120 has a configuration in which it is difficult to modify the inside as one LSI, tampering can be made difficult.
[0043]
In the first to fourth embodiments, message information to the user is generated in the playback device, but a terminal for outputting the disc playback stop information 114 is provided, and the disc playback stop information 114 is displayed as video data. The same effect can be obtained even if the message information is generated by the device on the sending side and sent to the device, the audio output device, the compressed video data or audio data decompression device, and the like.
[0044]
【The invention's effect】
As described above, according to the present invention, the detection by the copy permission information detection means is performed between the demodulation means and error correction means that are the processing means of the reproduction signal and the output control means, that is, the copy permission control information is detected. The reproduction permission information detecting means receives and detects the reproduction signal suitable for the recording, and the output control means performs the output control according to the result of the detection processing, so that each means for performing the reproduction signal processing temporarily stores the reproduction signal. The circuit scale can be reduced.
[0045]
Further, it is possible to make tampering difficult by configuring the signal processing LSI as one LSI that is difficult to modify the inside. The signal processing LSI outputs data after performing demodulation and error correction, and when the recorded data is image data compressed by MPEG, outputs the data after decompression processing. However, in any case, it is possible to prevent the system from being tampered with by using one LSI.
[Brief description of the drawings]
FIG. 1 is a block diagram of a DVD playback apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram of a DVD playback apparatus according to a second embodiment of the present invention.
FIG. 3 is a block diagram of a DVD playback apparatus according to a third embodiment of the present invention.
FIG. 4 is a block diagram of a DVD playback apparatus according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 ... Storage medium, 102 ... Pickup, 103 ... Preamplifier, 104 ... Demodulation means, 105 ... RAM, 106 ... Error correction means, 107 ... Disc identification code detection means, 108 ... Duplication permission information detection means, 109 ... Disc reproduction stop signal Generating means, 110... Message information generating means, 116... Wobble detecting means, 117.

Claims (7)

An error correction code for error correction is added to video data or audio data generated by superimposing a digital watermark on digital copy information or audio signal as a digital watermark, and is suitable for recording media A playback device that plays back video data or audio data from a read-only medium or a recordable medium that is modulated and recorded according to a modulation rule,
Means for determining whether the medium to be reproduced is a reproduction-only medium, demodulation means for demodulating the modulated data in accordance with the modulation rule, and temporary storage means for holding the demodulated data demodulated by the demodulation means And error correction means for performing error correction processing on the demodulated data stored in the temporary storage means by the error correction code , and superimposing as an electronic watermark from the error correction processed data stored in the temporary storage means Means for reproducing the information relating to copying permission, and the information relating to copying permission is reproduced when it is determined that the information relating to copying permission is one-time copying and the medium to be reproduced is a reproduction-only medium. the data is processed, and an output control means for outputting stop processing, video data or audio data reproducing apparatus comprising a.   2. A video data or audio data reproducing apparatus according to claim 1, wherein said temporary storage means is a RAM.   3. The video data or audio data reproducing apparatus according to claim 2, wherein the demodulating means, the error correcting means, and the copy permission information reproducing means are each connected to the RAM. Audio data playback device.   4. The video data or audio data reproducing apparatus according to claim 3, wherein the RAM is a single RAM.   3. The video data or audio data reproducing apparatus according to claim 2, wherein the copy permission information reproducing means, the demodulating means, the error correcting means, and the RAM are integrated into a single semiconductor device. . An error correction code for error correction is added to video data or audio data generated by superimposing a digital watermark on digital copy information or audio signal as a digital watermark, and is suitable for recording media A playback device that plays back video data or audio data from a read-only medium or a recordable medium that is modulated and recorded according to a modulation rule,
Means for determining whether the medium to be reproduced is a reproduction-only medium;
Demodulation means according to the modulation rule;
Temporary storage means for holding demodulated data demodulated by the demodulation means; error correction means for performing error correction processing according to the error correction code on the demodulated data stored in the temporary storage means;
Means for reproducing information relating to copying permission superimposed as a digital watermark from the video data or audio data subjected to error correction stored in the temporary storage means;
When it is determined that the copy permission information from the copy permission information reproducing means is one-time copying and the medium to be reproduced is a reproduction-only medium, a means for stopping reproduction of video data or audio data is a single An apparatus for reproducing video data or audio data, wherein the apparatus is integrated with a semiconductor device. An error correction code for error correction is added to video data or audio data generated by superimposing a digital watermark on digital copy information or audio signal as a digital watermark, and is suitable for recording media A reproduction method for reproducing video data or audio data from a read-only medium or a recordable medium that has been modulated and recorded according to a modulation rule,
Medium to be reproduced, it is determined whether the reproduction-only medium, and demodulated by the demodulating means,蓄example, for the data of the demodulated stored in the temporary storage means into the temporary storage means the demodulated data, There row error correction, to reflect the error correction result to the data of the temporary storage means, playback processing information on permission of the superimposed copy as a digital watermark from correcting the processed data stored in said temporary memory means and management information about the permission of the copy is the copying once permitted, when the medium to be reproduced is determined to be a read-only medium, reproducing method characterized by stopping reproduction of the video data or audio data.

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