JP3927928B2 - Information playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information reproducing apparatus, and in particular, information reproducing for realizing a system for simultaneously reproducing other information of a plurality of channels for one information, for example, a multilingual system for simultaneously reproducing audio of a plurality of channels for video Relates to the device.
[0002]
[Prior art]
In recent years, the spread of DVDs has been remarkable, and video / audio playback devices using DVDs have been introduced in airplanes and museums where many audiences can enjoy a single video. Yes. In such situations, the reality is that the audience is not limited to those who speak the same language.
[0003]
On the other hand, in DVD, in accordance with the DVD-Video standard, one video stream, up to eight corresponding audio streams, and up to 32 sub-picture streams are multiplexed into one set of programs. It is possible to introduce a DVD as a multilingual system that can supply audio that matches the language understood by each person even in the situation described above. It is.
[0004]
In addition, for in-flight applications, movies before the release are usually shown on the ground, and the content of such movies before the release does not leak to the outside, and even if it leaks, There is a strong demand for the construction of a system that introduces the concept of copyright protection that can track where the content that has been leaked from.
[0005]
The basic concept of copyright protection is to encrypt the content in order to prevent the content from leaking to the outside, and the digital video data that is played back includes the date and time of playback, the media of the played media The ID, the device ID of the device to be played back, and the content ID that shows the copyright information such as the title of the work and the name of the creator, etc. are embedded by digital watermarking technology, etc. It is common.
[0006]
2. Description of the Related Art Conventionally, as a video / audio reproduction device that realizes a multilingual system using a DVD, those described in Patent Documents 1 and 2 are known. For example, in the method described in Patent Document 1, the audio data of each language is extracted from the audio data in the presentation data also reproduced from the DVD with reference to the navigation data reproduced from the DVD, A multilingual system is disclosed which is realized by arranging a plurality of audio decoders for decoding individually in parallel. Patent Document 2 discloses a configuration in which audio data is distributed based on the stream ID of the audio stream, decoded by each decoding unit, and output to a predetermined signal channel.
[0007]
In general, an audio / video reproduction apparatus using a current DVD is configured to output one audio selected from a plurality of audios for one video. In general, an AV decoder in which a plurality of audio decoders are built in one chip so that a plurality of sounds can be output simultaneously for one video is not widely used. For this reason, when a multilingual system such as that described above is configured, a method is realized in which a plurality of inexpensive commercial AV decoders that are distributed in large quantities, each including one video decoder and one audio decoder, are arranged in parallel. Is taken.
[0008]
FIG. 6 is a configuration diagram of a conventional video / audio reproduction device that realizes the copyright protection function in such a multilingual system.
[0009]
The stream data reproducing unit 100 multiplexes information-compressed video information and information-compressed audio information of a plurality of channels (first to n-th channels (n is a natural number)) from a recording medium 1 such as a DVD. Play the multiplexed stream.
[0010]
Since the multiplexed stream reproduced by the stream data reproduction unit 100 is encrypted for copyright protection (for example, encryption such as Triple-DES), the decryption unit 101 includes a stream data reproduction unit. The encryption of the multiplexed stream reproduced by 100 is decrypted.
[0011]
The first stream decoder (AV decoder) 102 decompresses information on the multiplexed stream whose cipher has been decrypted.
[0012]
The video management information embedding unit 103 embeds video management information such as playback date, disk ID, device ID, and content ID in the video data that has been decompressed by the first stream decoder 102.
[0013]
The video output unit 104 generates a playback video signal from video data in which video management information is embedded. The reproduced video signal is output from the video output terminal 105 to the outside.
[0014]
The first audio output unit 106 generates a reproduced audio signal based on the first audio data expanded by the first stream decoder 102. The reproduced audio signal is output to the outside via the audio output terminal 107.
[0015]
The second to n-th stream decoders 108 to 110 decompress the multiplexed stream input to the first stream decoder 102 in the same manner as the first stream decoder 102. The second to n-th audio output units 111 to 113 generate reproduction audio signals based on the second to n-th audio data expanded by the second to n-th stream decoders 108 to 110, respectively. Each reproduced audio signal is output to the outside via each of the audio output terminals 114 to 116.
[0016]
The audio output is supplied to each person's headphones or the like by selecting a language understood by each user when the user selects any of the first to nth audio output terminals 107 and 114 to 116.
[0017]
[Patent Document 1]
JP-A-11-164257
[Patent Document 2]
Japanese Patent Laid-Open No. 8-31096
[0018]
[Problems to be solved by the invention]
In the conventional video / audio reproduction device having the above-described configuration, the multiplexed streams in which the video and audio decoded by the decryption unit 101 are multiplexed at the time of video / audio reproduction are the first to nth stream decoders. 102 and 108 to 110 are equally input. That is, the unprotected multiplexed stream after decryption flows on all data bus lines connected to the second to nth stream decoders 108 to 110. In FIG. 6, the flow of data indicated by the thick arrows is a multiplexed stream in a state where protection after decryption is not performed. In this way, the multiplexed streams in an unprotected state flow on all the data bus lines connected to the second to nth stream decoders 108 to 110, so that the multiplexed streams are transmitted from these data bus lines. The risk of extracting and illegal copying increases. For this reason, it has been necessary to protect all data bus lines by molding them with resin or the like on the circuit board of the reproducing apparatus.
[0019]
As described above, regarding the distribution of multiplexed streams after decryption, there is a strong demand for improvement in the degree of security for copyright protection so that the copyright is more strongly protected.
[0020]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an information reproducing apparatus that improves the degree of security against copyright protection in the information reproducing apparatus.
[0021]
[Means for Solving the Problems]
The first information reproducing apparatus according to the present invention includes first information that has been compressed and encrypted, and second information of a plurality of channels that is compressed and encrypted and reproduced in synchronization with the first information. Reproducing means for reproducing multiplexed data in which data is multiplexed, decrypting means for decrypting the cipher of the data reproduced by the reproducing means, and first decoding for decompressing the data decrypted by the decrypting means Means for analyzing the data decrypted by the decryption means and detecting the first information, and based on the analysis result of the analysis means, the first information contained in the data decrypted by the decryption means 2nd to n-th decoding (n is a natural number of n> 1) that receives at least a part of the conversion means and the modified data received from the conversion means and decompresses the second information of each predetermined channel. Means.
[0022]
A second information reproducing apparatus according to the present invention comprises a reproducing means for reproducing a multiplexed stream obtained by multiplexing information-compressed and encrypted video information and information-compressed and encrypted audio information of a plurality of channels. A decryption means for decrypting the cipher of the multiplexed stream reproduced by the reproduction means, and a first information for decompressing video information and audio information of one channel included in the multiplexed stream decrypted by the decryption means. Decoding means, management information embedding means for embedding video management information in the video data decompressed by the first decoding means, and generating a playback video signal from the video data in which the video management information is embedded by the management information embedding means Video output means, first audio output means for generating a reproduced audio signal from the audio data decompressed by the first decoding means, and decryption by the decryption means Analyzing the multiplexed stream and detecting video information, and modifying at least a part of the video information contained in the multiplexed stream decrypted by the decryption means based on the analysis result from the analysis means Stream converting means, second to n-th (n is a natural number where n> 1) decoding means for receiving the multiplexed stream modified from the converting means and decompressing the audio information of a predetermined channel, respectively. Second to nth audio output means for generating a reproduction audio signal from the audio data decompressed by each of the nth audio decoding means.
[0023]
above First and second The information reproducing apparatus further has means for switching between two data paths. Prepare . The first switching means, when a predetermined control signal is input, the reproduction data from the reproduction means bypasses the decryption means and inputs it to the first decryption means, and otherwise the reproduction from the reproduction means The data path is switched so that the data is input to the decryption means. The second switching means inputs reproduction data from the reproduction means to each of the second to n-th decoding means when the control signal is inputted, and from the conversion means (stream conversion means) otherwise. The data path is switched so that data is input to each of the second to nth decoding means.
[0024]
Further, the decryption unit, the analysis unit, the conversion unit, the first switching unit, and the second switching unit may be integrated so that they cannot be separated.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an information reproducing apparatus according to the present invention will be described with reference to the accompanying drawings. In the following, a video / audio reproduction device that realizes a multilingual system capable of simultaneously reproducing audio information of a plurality of channels for one video information will be described as an example.
[0026]
(Embodiment 1)
FIG. 1 is a diagram showing the configuration of a video / audio reproduction apparatus according to the present invention. In the figure, the arrow indicated by a thick line indicates a data bus line through which unencrypted and weakly protected data can flow.
[0027]
The video / audio reproduction device includes a stream data reproduction unit 100 that reproduces a stream in which video / audio information is multiplexed from a recording medium 1 such as a DVD, a decryption unit 101 that decrypts a cipher of the reproduced stream, and a decryption A stream analysis unit 10 that analyzes a stream, a stream conversion unit 11 that modifies video information according to the analysis result, first to n-th stream decoders 102 and 108 to 110 that decode a reproduced stream, and a reproduction stream Video management information embedding unit 103 that embeds management information for right protection, video output unit 104 that generates an analog playback video signal from the playback stream, and a first that generates analog playback audio signals of the first to n-th channels from the playback stream To n-th audio output units 106 and 111 to 113.
[0028]
Furthermore, the video / audio reproduction device includes a video output terminal 105 that outputs a reproduction video signal and audio output terminals 107 and 114 to 116 that output analog audio reproduction signals of the first to n-th channels, respectively.
[0029]
The operation of the video / audio reproduction device configured as described above will be described below. In the following, an operation during reproduction when a DVD is used as an example of a recording medium will be described.
[0030]
First, video / audio information recorded on a DVD to be reproduced will be described. A DVD is a stream in which video information and audio information of first to nth channels (n is a natural number, and a maximum of eight channels in the case of a DVD) reproduced in synchronization therewith are compressed and multiplexed. (Hereinafter referred to as “multiplexed stream”) is recorded. The multiplexed stream is encrypted for copyright protection, for example, encryption by Triple-DES.
[0031]
As shown in FIG. 2, in a DVD, one unit of content such as a movie work is recorded as a video object set (hereinafter referred to as “VOBS”) 50.
[0032]
The VOBS 50 includes a plurality of video objects (hereinafter referred to as “VOBs”) 51, and an ID number (IDNi (i is an integer)) assigned to each VOB 51 is an i-th VOB. Is an ID that means
[0033]
The DVD is configured to have different story development for each VOB, for example, corresponding to a multi-story function in which one movie can be viewed with a plurality of story developments.
[0034]
The VOB 51 includes a plurality of cells 52, and an ID number (IDNj (j is an integer)) assigned to each cell 52 is an ID indicating the jth cell.
[0035]
The cell 52 is a unit of one scene in a movie, for example. That is, the combination for each scene becomes VOB 51, and the above-described multi-story function is realized by the difference in the combination. The cell 52 includes a plurality of video object units (hereinafter referred to as “VOBU”) 53.
[0036]
One VOBU 53 always starts with one navigation pack (NV_PCK) 54, and includes a plurality of audio packs (A_PCK) 55, a plurality of video packs (V_PCK) 56, and a plurality of sub-picture packs (SP_PCK) 57.
[0037]
The navigation pack 54 is mainly used as control data for performing reproduction display control of data in the VOBU 53 to which the navigation pack 54 belongs and control data for performing data search of the VOBU 53.
[0038]
The video pack 56 is main video information and is compressed according to a standard such as MPEG. The sub-picture pack 57 is sub-picture information having auxiliary contents such as a caption super for the main picture. The audio pack 55 is audio information.
[0039]
In this way, the video, sub-picture, and audio streams are multiplexed with each pack as a unit.
[0040]
Next, the pack structure will be described. The main video information is recorded in the data area of the DVD as a pack row.
[0041]
All packs have a pack length of 2048 bytes regardless of the type. Video packs, sub-picture packs, and audio packs that make up presentation data are each composed of a 14-byte pack header and one or more packets that fill the remaining 2034 bytes. The pack length is adjusted by inserting stuffing bytes (FFh) into the packet header in the packet until the number of adjustment data is 7 bytes so that the pack length is always 2048 bytes. Padding packet as final packet (heading start code: 000001h, padding stream ID: BEh consisting of BEh, 4 bytes), packet length (2 bytes), and number necessary to adjust pack length This is adjusted by inserting a padding byte of FFh.
[0042]
The pack header is a 4-byte pack start code (000001BAh), a basic synchronization signal in the AV decoder, and an SCR (System Clock Reference) that sets and calibrates the system time clock (STC) as a time reference. It is a value, and in 6 bytes, an identification code represented by 2 bits of MPEG1: 00b and MPEG2: 01b is included at the beginning.) Multiplex expressed in units of 50 bytes / second The stream multiplexing rate (6 bytes) and the stuffing byte length (1 byte: since there is no stuffing byte in DVD, its value is fixed to F8h).
[0043]
FIG. 3 shows the structure of the video pack 56. The video pack 56 includes a pack header 61 and a video packet (V_PKT) of 2034 bytes or less. When the pack length is less than 2048 bytes, the video pack 56 is adjusted by the above method.
[0044]
The video packet has a packet header 62 and video data 63 fields. The packet header 62 includes the following fields.
Packet start code (4 bytes) 72: It is composed of a head start code (3 bytes: 000001h) and a video stream ID (1 byte: E0h).
Packet length (2 bytes) 73: This is the data length of the packet following this field, and the packet start code and the packet length of 6 bytes in total are not included in the packet length. -Flag and control (2 bytes) 74: Indicates the identification code represented by 2 bits of MPEG1 (other than 10b) and MPEG2 (10b), the presence or absence of conditional coding, and the like.
-PES header length (1 byte) 75: Data length of the packet header following this field. Represents the number of conditional coding data.
Conditional coding (0 to 20 bytes) 76: Reproduction output time management information PTS (Presentation Time Stamp) 78 and information decompression time management information DTS (Decoding Time) that are specified to be added to the packet in accordance with the packet generation rule (Stamp) 79 and other packet conditions are described. variable length.
[0045]
Video data (1 to 2025 bytes) 63 is an elementary stream divided for each packet.
[0046]
The video / audio reproduction device performs the reproduction operation as follows.
[0047]
The stream data reproducing unit 100 is a DVD drive, and reproduces a multiplexed stream in which information-compressed video information and n-channel information-compressed audio information are multiplexed from a DVD.
[0048]
The decryption unit 101 decrypts the encrypted encrypted stream reproduced by the stream data reproduction unit 100. That is, the decryption unit 101 decrypts the encryption for copyright protection applied to the payload in the packet (for example, video data in the case of a video packet).
[0049]
The first stream decoder 102 decompresses information on the multiplexed stream decrypted by the decryption unit 101. Specifically, the first stream decoder 102 refers to the navigation data in the multiplexed stream, searches for presentation data (video / audio / subpicture) according to the instruction, and MPEG-compressed video data And the audio information (first audio data) of one predetermined channel are decompressed. The first stream decoder 102 is realized by, for example, a commercially available low-priced AV decoder that is distributed in large quantities, each including a video decoder and an audio decoder (the same applies to the other stream decoders 108 to 110).
[0050]
The video management information embedding unit 103 embeds video management information such as playback date / time, disc ID, device ID, and content ID in the video information expanded by the first stream decoder 102.
[0051]
The video output unit 104 performs video encoding and DA conversion on the video information in which the video management information is embedded, and outputs the video information to the outside through the video output terminal 105 as a playback video signal such as NTSC / PAL. A video display device such as a monitor is connected to the video output terminal 105.
[0052]
The first audio output unit 106 outputs the reproduced audio signal obtained by DA-converting the first audio data whose information is decompressed by the first stream decoder 102 to the outside via the audio output terminal 107. Headphones or the like are connected to the audio output terminal 107 (the same applies to the other audio output terminals 114 to 116).
[0053]
The stream analysis unit 10 performs stream analysis on the multiplexed stream input to the first stream decoder 102 and detects video information. The stream conversion unit 11 modifies the video information in the multiplexed stream input to the first stream decoder 102 based on the analysis result of the stream analysis unit 10. Details of these operations will be described later.
[0054]
The second to n-th stream decoders 108 to 110 decompress the multiplexed stream in which the video information is modified by the stream converter 11. In particular, the 2nd to nth stream decoders 108 to 110 decompress the audio information (2nd to nth audio data) of predetermined channels in the multiplexed stream, respectively. The 2nd to nth audio output units 111 to 113 DA-convert the 2nd to nth audio data whose information has been decompressed by each of the 2nd to nth stream decoders 108 to 110 to generate a reproduced audio signal. And output to the outside via the audio output terminals 114 to 116.
[0055]
A plurality of audio outputs corresponding to one video output are supplied to headphones of each user by selecting the language understood by each user by switching the first to nth audio output terminals 107 and 114 to 116. The
[0056]
Operations related to the stream analysis unit 10 and the stream conversion unit 11 will be described in detail.
[0057]
The stream analysis unit 10 analyzes the output from the decryption unit 101 and outputs the analysis result to the stream conversion unit 11. The stream conversion unit 11 modifies the video information of the multiplexed stream output from the decryption unit 101 based on the analysis result of the stream analysis unit 10.
[0058]
More specifically, the stream analysis unit 10 first detects the pack start code 70 described in the pack header 62 included at the head of the pack, and counts the number of byte data in the pack from that point. By identifying the position of the packet start code 72 in the packet header and referring to the packet start code 72, the stream ID 77 written therein is obtained. Based on the stream ID 77, the pack currently viewed is It is detected whether or not the video pack stores video information to be modified.
[0059]
When the video pack storing the video information to be modified is detected, the stream conversion unit 11 refers to the PES header length 75 described in the packet header 62 and corresponds to the data length of the conditional coding 76. The beginning of the changing video data 63 is calculated. When the head of the video data 63 is calculated, it can be determined that video data is stored thereafter. That is, the stream converter 11 can recognize the data length of the video data to be modified by referring to the PES header length 75. The stream converter 11 uses all data from the beginning of the video data 63 to the end of the video pack as data uncorrelated with the original data, for example, stuffing bytes or padding bytes discarded by the stream decoders 108 to 110. Replace with “FFh”.
[0060]
The video data contains supplementary information and video information necessary for decompressing the compressed video information, so the content can be invalidated by replacing the content with data that is uncorrelated with the original data. Information cannot be correctly decompressed, and correct playback video cannot be obtained. That is, since all of the video data in the video pack is replaced, the original video data cannot be reproduced as one. As a result, the copyright can be strongly protected.
[0061]
Here, the incidental information in the video data is a quantum that is a weight that gives different sensitivity to each location of the DCT coefficient so that the roughness of quantization can be changed for each frequency of DCT (discrete cosine transform). Data such as motion vector information indicating the amount of movement with the comparison block in the reference screen. The video information itself in the video data is a DC coefficient, a DC difference value, an AC coefficient, etc. in a DCT block which is a basic unit of compression for performing DCT calculation. DCT is one of orthogonal transforms that transform image data into frequency components.
[0062]
As described above, according to the present embodiment, the video information in the stream input to the second to nth stream decoders 108 to 110 for the multilingual function is modified by the stream converter 11. For this reason, since the stream in which the video information is modified flows on the data bus line between the stream conversion unit 11 and the second to n-th stream decoders 108 to 110, even on these data bus lines. Even if the stream is extracted, video information cannot be reproduced, so that sufficient protection is realized. That is, in this embodiment, a multiplexed stream with weak protection after decryption flows only on the data bus lines indicated by thick solid lines in FIG. 1, and the number of data bus lines through which the multiplexed stream with weak protection after decryption flows. It is sufficient to protect at least this part with a resin mold or the like, and the degree of security can be further improved as compared with the conventional one.
[0063]
The second to n-th stream decoders 108 to 110 cannot decode and output a correct reproduced video signal, but time information (time stamp (time stamp)) included in the incidental information of both the video information stream and the audio information stream. Since PTS, DTS) and time base reference value (SCR) are not modified, video and audio can be correctly synchronized based on such information. Therefore, the reproduced video from the video output terminal 105 and the reproduced audio from the first to nth audio output terminals 107 and 114 to 116 can be always synchronized correctly.
[0064]
In this embodiment, the video data is replaced with “FFh”. However, any data may be used as long as the data is uncorrelated with the video data. For example, it may be replaced with random data. Further, it may be replaced with video management information such as reproduction date / time, disc ID, device ID, content ID, etc. embedded in the video management information embedding unit 103, and in this case, it is particularly effective for tracking out the destination of unauthorized copy. Further, if the reproduced video information becomes substantially unusable, only a part of the data may be replaced instead of replacing the entire video data 63.
[0065]
In this embodiment, the video data in the video pack is modified. However, not only the video pack but also the sub-picture data in the sub-picture pack and the audio data in the audio pack are modified in the same manner. Can be modified.
[0066]
Each of the first to nth stream decoders 102 and 108 to 110 may decode audio information of different channels, or all or part of the stream decoders 102 and 108 to 110 may have the same channel. The signal may be reproduced. At least a part of the stream decoders 102 and 108 to 110 decodes and outputs the audio information of the same channel, so that the user can select the one having the best reproduction state from among a plurality of audio signals for the channel. It becomes.
[0067]
In the present embodiment (the same applies to the following embodiments), a DVD is taken as an example and described as a constant bit rate multiplexed stream. However, the present invention is not limited to a constant bit rate multiplexed stream. The multiplexed data in which information is multiplexed can be configured similarly regardless of the bit rate.
[0068]
In the present embodiment (the same applies to the following embodiments), a multilingual system that simultaneously reproduces a plurality of sounds for one image has been described. However, for example, a plurality of images can be displayed for one sound. The idea of the present invention can also be applied to a system that plays back simultaneously. In this case, the video information and audio information may be replaced in the above description. Needless to say, the present invention can be similarly extended and applied even when there are a plurality of video and audio.
[0069]
Further, in this embodiment (the same applies to the following embodiments), the description has been made using the data stream transmitted in the processing order, but the idea of the present invention is not limited to the data stream. It can be widely applied to general data regardless of the concept of time flow.
[0070]
In the present embodiment (the same applies to the following embodiments), the case where video information and audio information are multiplexed has been described. However, the present invention is not limited to such information. Needless to say, the idea of the present invention can be applied to such information as long as one of the two information is reproduced in synchronization with the other and the other information is not required to have a higher security level than the other information. Yes. Examples of such combinations of information are as follows.
-High-resolution video information (for example, high-definition) and multi-channel low-resolution video information (for example, low-bit-rate MPEG video information).
-Video information and text information that conveys information in multiple different languages.
[0071]
(Embodiment 2)
FIG. 4 shows another configuration of the video / audio reproduction device according to the present invention. In the present embodiment, in addition to the configuration of the first embodiment, there are two stream switching units 20 and 21 for switching the stream path. In FIG. 4, arrows indicated by bold lines indicate data bus lines through which unencrypted data with weak protection can flow.
[0072]
The first stream switching unit 20 provides a stream path so that the multiplexed stream output from the stream data reproducing unit 100 is input to the decryption unit 101 or the first stream decoder 102 and the second stream switching unit 21. Is switched. That is, the first stream switching unit 20 switches the stream path so that the multiplexed stream from the stream data reproduction unit 100 bypasses or passes through the decryption unit 101.
[0073]
The second stream switching unit 21 is configured such that the multiplexed stream output from the first stream switching unit 20 or the decryption unit 101 is the second to nth stream decoders 108 to 110, or the stream analysis unit 10 and the stream conversion The stream path is switched so as to be input to the unit 11. The second stream switching unit 21 works in conjunction with the first stream switching unit 20, and when the multiplexed stream from the stream data reproduction unit 100 bypasses the decryption unit 101, the bypassed multiplexed stream is The stream path is switched so as to directly input to the 2nd to nth stream decoders 108 to 110.
[0074]
The operations of the first and second stream switching units 20 and 21 are controlled by a control signal input from the control signal input terminal 22.
[0075]
The operation of the video / audio reproduction device of the present embodiment configured as described above will be described.
[0076]
First, an operation when a control signal instructing to bypass the decryption unit 101 (that is, decryption by the decryption unit 101 is not required) is input to the control signal input terminal 22 will be described. As such a case, there are cases where the multiplexed stream reproduced from the DVD is not encrypted, or the reproduced multiplexed stream is encrypted other than the cipher that can be processed by the decryption unit 101. . At this time, the first stream switching unit 20 switches the stream path to the contact Q0 side, and the second stream switching unit 21 switches the stream path to the contact Q1 side.
[0077]
The first stream decoder 102 decompresses information on the multiplexed stream bypassing the decryption unit 101. At this time, if the multiplexed stream reproduced from the stream data reproducing unit 100 is CSS scrambled and the first stream decoder 102 needs to unscramble, the first stream decoder 102 receives the input The information is decompressed after the CSS scramble of the multiplexed stream is solved. However, in this case, the first stream decoder 102 needs to include a CSS descrambler.
[0078]
The second stream switching unit 21 is configured so that the multiplexed stream that bypasses the decryption unit 101 bypasses the stream analysis unit 10 and the stream conversion unit 11 according to the control signal input from the control signal input terminal 22. Switch the stream path.
[0079]
The second to n-th stream decoders 108 to 110 decompress information on the multiplexed stream that bypasses the stream analysis unit 10 and the stream conversion unit 11.
[0080]
Next, an operation when a control signal instructing not to bypass the decryption unit 101 is input to the control signal input terminal 22 will be described. At this time, the first stream switching unit 20 switches the stream path to the contact P0 side, and the second stream switching unit 21 switches the stream path to the contact P1 side. The operation of the video / audio reproduction device in this case is the same as the operation described in the first embodiment.
[0081]
As described above, according to the present embodiment, the two stream switching units 20 and 21 control the detour / pass with respect to the decryption unit 101 in conjunction with each other according to the necessity of decryption. As a result, playback of unencrypted commercial DVDs that are already widely distributed in the market that does not require decryption during playback, and playback of commercial DVDs that are scrambled such as CSS well known as DVD copy protection Can be realized flexibly.
[0082]
(Embodiment 3)
FIG. 5 shows still another configuration of the video / audio reproduction device according to the present invention. In the present embodiment, in addition to the configuration of the first embodiment, first and second stream switching units 23 and 24 for switching the stream path are further provided. In the present embodiment, the first stream switching unit 23 is provided more on the stream decoder side than in the second embodiment. In FIG. 5, an arrow indicated by a thick line indicates a data bus line through which unencrypted unprotected data can flow.
[0083]
The first stream switching unit 23 inputs either the multiplexed stream reproduced from the stream data reproducing unit 100 or the multiplexed stream decrypted by the decryption unit 101 to the first stream decoder 102. Select a stream path. That is, the first stream switching unit 23 switches the path so that the multiplexed stream from the stream data reproducing unit 100 bypasses or passes through the decryption unit 101.
[0084]
The second stream switching unit 24 receives either the multiplexed stream from the stream data reproducing unit 100 or the multiplexed stream whose video information has been modified by the stream converting unit 11 from the second to n-th stream decoders 108. Select the stream path to be input to .about.110. The second stream switching unit 24 works in conjunction with the first stream switching unit 23, and when the multiplexed stream from the stream data reproduction unit 100 bypasses the decryption unit 101, the second stream switching unit 24 performs multiplexing from the stream data reproduction unit 100. The stream path is switched so that the stream is directly input to the second to nth stream decoders 108 to 110.
[0085]
The first and second stream switching units 23 and 24 are controlled by a control signal input via the control signal input terminal 22.
[0086]
Further, as shown by a double line in FIG. 5, the decryption unit 101, the stream analysis unit 10, and the stream conversion unit 11 are integrated with the first and second stream switching units 23 and 24 so that they cannot be separated. (30). For example, the integration is realized by packaging as a device that cannot be disassembled such as a gate array or an ASIC, and the integrated elements do not operate independently, and a data bus line and a control signal line between the elements. Can not be accessed from the outside.
[0087]
The operation of the video / audio reproduction device configured as described above will be described.
[0088]
When a multiplexed stream that is not encrypted is reproduced from a DVD, a control signal that does not instruct decryption is input from the terminal 22. Based on this control signal, the first stream switching unit 23 switches the contact point to R0, and the second stream switching unit 24 switches the contact point to R1. As a result, the output from the stream data reproduction unit 100 is directly input to the first to nth stream decoders 102 and 108 to 110.
[0089]
The first stream decoder 102 decompresses the multiplexed stream selected by the first stream switching unit 23. When the CSS scramble is applied to the multiplexed stream reproduced from the stream data reproducing unit 100, the first stream decoder 102 decompresses the information after decomposing the CSS scramble of the inputted multiplexed stream. However, the first stream decoder 102 needs to include a CSS descrambler.
[0090]
On the other hand, when a multiplexed stream to which encryption is applied is reproduced from a DVD, a control signal instructing decryption is input via the terminal 22. Based on this control signal, the first stream switching unit 23 selects the output from the decryption unit 101 with the contact point set to the S0 side. The second stream switching unit 24 selects the output from the stream conversion unit 11 with the contact point on the S1 side.
[0091]
The multiplexed stream decrypted by the decryption unit 101 is automatically input to the stream analysis unit 10 and the stream conversion unit 11, and the video information is modified. The subsequent operation is as described in the first embodiment.
[0092]
As described above, in the present embodiment, the decryption unit 101, the stream analysis unit 10, and the stream conversion unit 11 are integrated, and further configured so as not to be separated together with the stream switching units 23 and 24. Therefore, it is possible to reduce the number of data bus lines (bus lines indicated by thick solid lines in FIG. 4) through which a stream is transmitted, and to configure a video / audio reproduction device with high security and easy board design.
[0093]
【The invention's effect】
According to the information reproducing apparatus of the present invention, the decrypted multiplexed stream distributed for the multilingual function is distributed to each decryption means after the video information included in the stream is modified. Since the number of bus lines through which weakly protected data flows later can be reduced, illegal copying due to extraction of data during the distribution can be prevented, and an information reproducing apparatus with high security in copyright protection can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a video / audio reproduction device according to the present invention (Embodiment 1);
FIG. 2 is a data structure diagram of a video object set (VOBS).
FIG. 3 is a data structure diagram of a video pack (V_PCK).
FIG. 4 is a diagram showing another configuration of the video / audio reproduction device according to the present invention (Embodiment 2);
FIG. 5 is a diagram showing still another configuration of the video / audio reproduction device according to the present invention (Embodiment 3);
FIG. 6 is a configuration diagram of a conventional video / audio reproduction device.
[Explanation of symbols]
1 Recording medium (DVD)
10 Stream analyzer
11 Stream converter
20, 23 First stream switching unit
21, 24 Second stream switching unit
22 Control signal input terminal
100 Stream data playback unit
101 Decryption part
102, 108-110 Stream decoder
103 Video management information embedding unit
104 Video output unit
105 Video signal output terminal
106, 111, 112, 113 Audio output unit
107, 114-116 Audio signal output terminal

Claims (12)

Reproduces multiplexed data in which the first information compressed and encrypted and the second information of a plurality of channels that are compressed and encrypted and reproduced in synchronization with the first information are multiplexed. Reproduction means,
Decryption means for decrypting the encryption of the data reproduced by the reproduction means;
First decryption means for decompressing data decrypted by the decryption means;
Analyzing the data decrypted by the decryption means, and detecting the first information;
Conversion means for modifying at least a part of the first information included in the data decrypted by the decryption means based on the analysis result of the analysis means;
Second to nth (n is a natural number where n> 1) decoding means for receiving the modified data from the conversion means and decompressing the second information of each predetermined channel;
When a predetermined control signal is input, the playback data from the playback means bypasses the cryptanalysis means and is input to the first decryption means. Otherwise, the playback data from the playback means is the encrypted data. First switching means for switching the data path for input to the decoding means;
When the control signal is inputted, the reproduction data from the reproduction means is inputted to each of the second to n-th decoding means, and otherwise, the data from the conversion means is inputted to the second to n-th decoding means. An information reproducing apparatus comprising: second switching means for switching a data path so as to be input to each of the decoding means . Said decryption means, said analyzing means, said converting means, said first switching means and integrated with the second switching means, the information reproducing apparatus according to claim 1, characterized in that the separation can not configure .   2. The information reproducing apparatus according to claim 1, wherein the converting means does not modify time information necessary for synchronous reproduction of the first information and the second information.   2. The information reproducing apparatus according to claim 1, wherein the converting means changes a data area to be modified based on predetermined data length information in a multiplexing unit.   2. The information reproducing apparatus according to claim 1, wherein the converting unit replaces the data to be modified with data uncorrelated with the data to be modified. The multiplexed data information reproducing apparatus according to any one of claims 1 to 5, characterized in that a data stream. Wherein one of the first and second information is video information, the information reproducing apparatus according to claim 1, wherein the other is audio information. Playback means for playing back a multiplexed stream in which information-compressed and encrypted video information and information-compressed and encrypted audio information of a plurality of channels are multiplexed;
Decryption means for decrypting the encryption of the multiplexed stream reproduced by the reproduction means;
First decoding means for decompressing video information and audio information of one channel included in the multiplexed stream decrypted by the decryption means;
Management information embedding means for embedding video management information in the video data decompressed by the first decoding means;
Video output means for generating a video signal for reproduction from video data in which video management information is embedded by the management information embedding means;
First audio output means for generating a reproduced audio signal from the audio data decompressed by the first decoding means;
A stream analyzing means for analyzing the multiplexed stream decrypted by the decryption means and detecting video information;
Based on the analysis result from the analysis means, a stream conversion means for modifying at least a part of the video information included in the multiplexed stream decrypted by the decryption means;
Second to n-th (n is a natural number where n> 1) decoding means for receiving the modified multiplexed stream from the conversion means and decompressing audio information of a predetermined channel, respectively;
Second to nth audio output means for generating a reproduced audio signal from the audio data decompressed by each of the second to nth audio decoding means;
When a predetermined control signal is input, the playback data from the playback means bypasses the cryptanalysis means and is input to the first decryption means. Otherwise, the playback data from the playback means is the encrypted data. First switching means for switching the data path for input to the decoding means;
When the control signal is inputted, the reproduction data from the reproduction means is inputted to each of the second to n-th decoding means, and otherwise, the data from the stream conversion means is inputted to the second to n-th decoding means. An information reproducing apparatus comprising: second switching means for switching a data path so as to be input to each of the decoding means . 9. The information reproducing apparatus according to claim 8 , wherein the decryption unit, the analysis unit, the conversion unit, the first switching unit, and the second switching unit are integrated and cannot be separated. . 9. The information reproducing apparatus according to claim 8 , wherein the stream converting means does not alter time information necessary for synchronous reproduction of video information and audio information. 9. The information reproducing apparatus according to claim 8 , wherein the stream converting means changes a data area to be modified based on predetermined data length information in a multiplexing unit. 9. The information reproducing apparatus according to claim 8 , wherein the stream conversion unit replaces the data to be modified with data uncorrelated with the modified data.

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