JP2006277830A - Reproducing device, reproducing method, reproducing program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrict the use of contents in the case of reproducing them. <P>SOLUTION: The device for reproducing obtains digital contents for reproduction and a manifest from a medium in which the encrypted reproduction digital contents and data with respect to the manifest defining the reproducing conditions of the reproduction digital contents are stored to be made correspond to each other (step S202), obtains key data to be used for decoding the reproduction digital contents on the basis of the obtained data with respect to the manifest (step S210), decodes the reproduction digital contents on the basis of the key data (step S212), and reproduces the decoded reproduction digital contents (step S214). Thus, the reproduction digital contents are reproduced only when the conditions of the manifest and the key data are matched with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a playback device, a playback method, a playback program, and a recording medium.

  In recent years, opportunities for playing back digital content such as music and video have increased. For example, a medium in which such digital content is stored may also store commercial digital content representing the content of the digital content. Each of these digital contents is stored in a data system that can be played back by a general method (hereinafter referred to as a general data system), and dedicated software is required for playback. In some cases, the data is stored in a data format. In the latter case, dedicated software for playing back digital content is provided together with the digital content, for example. With regard to digital content management, there are various technologies aimed at preventing unauthorized use and improving management efficiency (see, for example, Patent Documents 1 and 2 below).

  In recent years, the MPV (Music Photo Video) standard, which is a standard for index data that summarizes information about digital content recorded on media or the like, has been developed. By using this MPV standard, for example, it is expected to improve the efficiency of content management.

JP 2002-190159 A JP 2004-87063 A

  By the way, when digital contents of a general data system are provided, for example, these digital contents can be copied to another medium and reused. That is, there is an inconvenience that it is difficult to limit the use of digital contents of a general data system.

  In addition, when digital contents stored in a data format that requires dedicated software are provided, dedicated software must be prepared in order to reproduce these digital contents, and the reproduction work is complicated. There is an inconvenience. In addition, even digital content stored on media in a data format that requires dedicated software can be reused by copying the digital content and the dedicated software together. There is an inconvenience that it is difficult to provide.

  However, for example, it is complicated for users of digital contents that have been acquired normally by making purchases or the like to place excessive restrictions on the use of digital contents, such as requiring input of a personal identification number every time it is used. There is a disadvantage of requiring work.

  The playback apparatus according to the present invention provides the playback digital content and the manifest from a medium in which encrypted digital content for playback and data relating to a manifest that defines playback conditions for the playback digital content are stored in association with each other. Data acquisition means for acquiring data related to the data, and key data for acquiring key data used for decrypting the digital content for reproduction acquired by the data acquisition means based on data related to the manifest acquired by the data acquisition means Obtaining means; decrypting means for decrypting the digital content for reproduction obtained by the data obtaining means based on the key data obtained by the key data obtaining means; and digital data for reproduction decrypted by the decrypting means Replay content Characterized in that it comprises a means.

  Therefore, a manifest is associated, and only the digital content for reproduction that can be decrypted using the key data acquired based on the manifest is reproduced. That is, the digital content for reproduction can be reproduced only when the conditions of the manifest and key data are met.

  In addition, the playback device of the present invention includes a communication unit that communicates with an external device that stores key data used for decrypting the digital content for playback, and the key data acquisition unit communicates with the communication unit. To obtain the key data stored in the external device.

  Therefore, key data can be acquired only when communication is performed with an external device in addition to the playback device. That is, it is possible to provide more restrictions when reproducing digital content for reproduction.

  Furthermore, the playback apparatus of the present invention further includes a determination unit that determines the presence or absence of data related to the manifest stored in a medium that is a target of data acquisition by the data acquisition unit, and the playback unit uses the manifest to determine the manifest. When it is determined that there is no data relating to the digital content, the digital content for simple reproduction different from the digital content for reproduction is reproduced.

  Therefore, when data related to the manifest is not stored in the media from which data is acquired, the digital data for simple reproduction different from the digital content for reproduction is associated with the data related to the manifest. It is possible to differentiate between a user who owns digital content for reproduction and other users.

  At this time, as digital content for simple playback, digital content with lower quality (image quality and sound quality) than digital content for playback, digital content constituting a part of digital content for playback, and digital content for playback By using the digital content for commercials that introduces the contents of the digital content, it is possible to play back digital content related to the digital content for playback.

  The reproduction method of the present invention includes the digital content for reproduction and the manifest from a medium in which encrypted digital content for reproduction and data relating to a manifest defining the reproduction condition of the digital content for reproduction are stored in association with each other. A data acquisition step for acquiring data related to the data, a key data acquisition step for acquiring key data used for decrypting the digital content for reproduction based on data related to the manifest acquired in the data acquisition step, and the data acquisition step A decryption step for decrypting the digital content for reproduction acquired by the key data acquired by the key data acquisition step, and a reproduction step for reproducing the digital content for reproduction decrypted by the decryption step; It is characterized by including.

  Therefore, a manifest is associated, and only the digital content for reproduction that can be decrypted using the key data acquired based on the manifest is reproduced. That is, the digital content for reproduction can be reproduced only when the conditions of the manifest and key data are met.

  The reproduction program of the present invention causes a computer to execute the reproduction method described above.

  Therefore, by executing the playback program of the present invention, the operation obtained by the playback method described above is realized by a computer.

  The recording medium of the present invention is characterized in that the above-described reproduction program is recorded so as to be readable by a computer.

  Therefore, various operations obtained by executing the above-described reproduction program are realized by causing the computer to read and execute the recorded reproduction program.

  Exemplary embodiments of a playback device, a playback method, a playback program, and a storage medium according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Schematic configuration of media player)
FIG. 1 is a block diagram showing a schematic configuration of a media player in the present embodiment. The media player 100 includes a control unit 101, a user operation input unit 102, a reading unit 103, an MPV manifest analysis unit 104, an encrypted content decryption key acquisition unit 105, an encrypted content decryption unit 106, and a playback unit. 107. In the present embodiment, a playback device is realized by the media player 100.

  The control unit 101 controls driving of each unit included in the media player 100. The control unit 101 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores various control programs, and a RAM (Random Access Memory) that functions as a work area of the CPU. It is realizable with the microcomputer etc. which are comprised by.

  In the ROM, a reproduction program for realizing the present invention is recorded. Thus, in the present embodiment, the recording medium of the present invention is realized by the ROM. In the ROM or RAM, for example, a memory area for temporarily storing media data read by the reading unit 103 may be secured. Note that the reproduction program is not limited to one recorded in the ROM.

  The user operation input unit 102 outputs information input by the user such as characters, numerical values, and various instructions to the control unit 101. As the configuration of the user operation input unit 102, various known forms such as a push button switch for detecting physical pressing / non-pressing, a touch panel, a keyboard, and a joystick can be employed. The user operation input unit 102 may be configured to perform an input operation by sound using a microphone that inputs sound from the outside.

  The user operation input unit 102 may be provided integrally with the media player 100, or may be configured to be operated separately from the media player 100 like a remote controller. The user operation input unit 102 may be configured in any one of the various forms described above, or may be configured in a plurality of forms.

  The user inputs information by appropriately performing an input operation according to the form of the user operation input unit 102. Examples of information input by an operation of the user operation input unit 102 include designation information for playback digital content and information regarding operation instructions such as playback and stop playback of the digital content.

  The reading unit 103 reads data recorded on the medium 110. In the present embodiment, a data acquisition unit is realized by the reading unit 103. The reading unit 103 according to the present embodiment reads, as a medium 110, for example, a medium 110 that uses light when reproducing data, such as a CD (including a CD-ROM, a CD-RW, etc.) and a DVD. To do.

  Media 110 in the present embodiment stores encrypted digital content for reproduction and data related to a manifest that defines the reproduction conditions for the digital content for reproduction. The digital content for reproduction according to the present embodiment is video data composed of moving image data, audio data, and the like. Note that digital content for reproduction is not limited to video data. The digital content for reproduction may be video only or audio only data. Further, it is not limited to moving image data, and may be still image data.

  The digital content for reproduction uses public key encryption that uses key data that is paired with the key data used at the time of encryption when decrypting the digital content for reproduction, and the same key data for encryption and decryption. Encryption is performed using a known encryption technique such as secret key encryption. Data related to the manifest is described according to an XML (extensible Markup Language) format.

  The manifest defines the playback conditions and the conditions that allow playback to be performed. Specifically, the manifest specifies a storage location of key data used when decrypting encrypted digital content for reproduction. Depending on the encryption method of the digital content for playback, the key data is the same for encryption and decryption as for private key encryption, even if encryption and decryption are different as in public key encryption. There may be.

  In addition, the media of the present embodiment stores digital content for simple reproduction different from the digital content for reproduction. Digital content for simple playback includes, for example, digital content with lower quality (image quality and sound quality) than digital content for playback, digital content that constitutes part of digital content for playback, and digital content for playback. This is digital content for commercials that introduces the content.

  Specifically, the reading unit 103 can be configured by, for example, an optical pickup, a spindle motor, a coarse motor, and various control circuits that control these. The optical pickup includes a light source that irradiates a target medium 110 with laser light and a light detector such as a photo detector that receives reflected light from the medium 110 when recording or reproducing information. In the optical pickup, the laser light emitted from the light source is adjusted so that the spot is minimized on the recording surface of the medium 110. The laser beam reflected on the recording surface is received in a state of being collected by the light receiving unit. The received optical signal is photoelectrically converted into an electrical signal.

  The control circuit that controls the optical pickup includes a signal processing circuit that performs various signal processing on the information signal from the medium 110 that has been photoelectrically converted by the optical pickup. Light is emitted with read power, and media data is reproduced based on the reflected light. The control circuit for controlling the optical pickup causes the light source to emit light with light power when recording information.

  The spindle motor rotationally drives the target medium 110. The control circuit that controls the rotation of the spindle motor controls the rotation of the spindle motor so that the target medium 110 rotates at a constant rotation speed. The coarse motion motor moves the optical pickup in the radial direction of the medium 110.

  Note that the medium 110 is not limited to reproduction using light. The reading unit 103 has a configuration suitable for each medium 110 that is a data reading target when using the medium 110 that uses a means other than light when reproducing data. In this embodiment, the portable medium 110 has been described, but the present invention is not limited to this.

  The MPV manifest analysis unit 104 analyzes data related to the manifest based on the media data read by the reading unit 103. By this analysis, the MPV manifest analysis unit 104 determines the presence / absence of data related to the manifest, and acquires data related to the storage location of the key data used for decryption of the digital content for reproduction when it is determined that there is data related to the manifest. In the present embodiment, a determination means is realized by the MPV manifest analysis unit 104. Further, through the analysis, the MPV manifest analysis unit 104 acquires the playback condition of the playback digital content.

  The encrypted content decryption key acquisition unit 105 acquires key data used for decryption of the digital content for reproduction based on the data related to the storage location of the key data acquired by the analysis by the MPV manifest analysis unit 104. In this embodiment, the encrypted content decryption key acquisition unit 105 realizes a key data acquisition unit.

  Specifically, the encrypted content decryption key acquisition unit 105 includes an I / F or the like as a communication unit that performs communication with the external device 120 provided separately from the media player 100. The key data is acquired by communicating with the external device 120 via the. The external device 120 can be realized by, for example, a server provided on a network connected via a public network or the like.

  When the external device 120 is realized by a server provided on the network, the external device 120 communicates with a control unit (not shown) that drives and controls each unit of the external device 120 and a communication (not shown) that performs communication with the media player 100. In addition to the means, a key data storage unit 121 that stores key data is provided. The key data storage unit 121 stores key data in association with information specifying digital content for reproduction.

  The external device 120 is not limited to a server or the like provided on the network. The external device 120 may be realized by a specific computer connected by a LAN connection or the like. The external device 120 may be realized by a storage medium that does not require a special drive device. Specifically, for example, the external device 120 may be realized by a flash memory such as a memory card.

  The key data is not limited to that associated with information for specifying digital content for reproduction. The key data may be associated with, for example, information (media ID) that identifies the medium 110 that stores the digital content for reproduction.

  Note that the key data is not limited to that stored in the external device 120. The key data may be stored in, for example, the medium 110 that stores data related to a manifest that specifies the storage location of the key data.

  The encrypted content decryption unit 106 decrypts the digital content for reproduction read by the reading unit 103 based on the key data acquired by the encrypted content decryption key acquisition unit 105. In the present embodiment, the encrypted content decrypting unit 106 implements decryption means.

  The playback unit 107 plays back the digital content for playback decrypted by the encrypted content decryption unit 106. When the playback digital content is not encrypted, the playback unit 107 plays back the playback digital content acquired from the reading unit 103. In the present embodiment, a reproducing unit is realized by the reproducing unit 107. Specifically, the reproduction unit 107 can be realized by, for example, an audio output speaker, an audio I / F connected to the speaker, a video I / F, and a display. More specifically, the audio I / F includes, for example, a D / A converter that performs D / A conversion of audio digital information, an amplifier that amplifies an audio analog signal output from the D / A converter, and audio analog information. And an A / D converter that performs A / D conversion.

  Specifically, the video I / F includes, for example, a graphic controller that controls the entire display device, a buffer memory such as a VRAM (Video RAM) that temporarily stores image information that can be displayed immediately, and a graphic controller. Based on the output image information, the display device is configured by a control IC or the like. The display includes, for example, a CRT (Cathode Ray Tube), a TFT liquid crystal display, an organic EL display, a plasma display, and the like.

  As a form of the user operation input unit 102, for example, when a touch panel is adopted, the touch panel can be used by being stacked on a display. In this case, the input information is recognized by managing the display timing on the display, the operation timing on the touch panel (user operation input unit 102), and the position coordinates thereof. As the touch panel, various known touch panels such as a resistive film type and a pressure sensitive type can be used.

(Processing procedure of the media player 100)
FIG. 2 is a flowchart showing the processing procedure of the media player 100. The process shown in FIG. 2 first determines whether or not there is a request for reading media data (step S201). If it is determined that there is no request for reading media data (step S201: No), the process stands by.

  If it is determined that there is a request for reading media data (step S201: Yes), the media data is read (step S202), and a content menu is displayed based on the read media data (step S203). It is determined whether or not digital content to be played back is designated with the content menu displayed (step S204). In FIG. 2, “has content to be reproduced been specified?” Is described as the process of step S204.

  When it is determined that the content to be played back is not specified (step S204: No), it is determined whether a predetermined time has elapsed with the content menu displayed (step S205). If it is determined that the predetermined time has not elapsed (step S205: No), the process proceeds to step S204. When it is determined that the fixed time has elapsed (step S205: Yes), the process proceeds to step S216.

  If it is determined that the content to be played is specified (step S204: Yes), it is determined whether there is data related to the manifest based on the read media data (step S206). In FIG. 2, “is there a manifest?” Is described as the process of step S206. If it is determined that there is no data related to the manifest (step S206: No), the process proceeds to step S215.

  If it is determined that there is data related to the manifest (step S206: Yes), it is determined whether there is digital content for reproduction based on the read media data (step S207). In FIG. 2, “is there content for reproduction?” Is described as the processing in step S207. If it is determined that there is no digital content for reproduction (step S207: No), the process proceeds to step S215.

  If it is determined that there is digital content for reproduction (step S207: Yes), digital content for reproduction is acquired (step S208). In FIG. 2, “acquisition of content for reproduction” is described as the process of step S208. Then, it is determined whether or not the acquired digital content for reproduction is encrypted (step S209). If it is determined that the digital content for reproduction is not encrypted (step S209: No), the process proceeds to step S214.

  If it is determined that the digital content for playback is encrypted (step S209: Yes), the key data used for decrypting the digital content for playback is based on the data related to the manifest in the read media data. Obtain (step S210). When acquiring the key data, data related to the storage location of the key data is acquired based on the data related to the manifest, and the storage location of the key data is accessed based on this data. In the present embodiment, communication with the external device 120 is performed, and key data stored in the key data storage unit 121 is acquired.

  When communicating with the external device 120, the external device 120 may request the media player 100 to input a media ID for identifying the media 110. In this case, the external device 120 stores the media ID in advance, and when there is a key data acquisition request from the media player 100, the stored media ID is searched, and the corresponding media ID is found. Allow key data acquisition only if it exists.

  Then, it is determined whether or not acquisition of key data has been performed normally (step S211). In FIG. 2, “Has key data been acquired?” Is described as the process of step S211. If it is determined that acquisition of key data has not been performed normally (step S211: No), the process proceeds to step S215.

  When the key data is stored in the external device 120, communication with the external device 120 is performed when acquiring the key data. In this communication, the key data may not be acquired normally if a communication error occurs.

  If it is determined that the key data has been acquired normally (step S211: Yes), the read digital content for reproduction is decrypted based on the acquired key data (step S212). Then, it is determined whether or not the read digital content for reproduction has been normally decrypted (step S213). In FIG. 2, “Has decoding been successful?” Is described as the process of step S213.

  When it is determined that the read digital content for reproduction has been normally decoded (step S213: Yes), the read digital content for reproduction is reproduced (step S214). When it is determined that the read digital content for reproduction has not been normally decrypted (step S213: No), the digital content for simple reproduction is acquired (step S215). In FIG. 2, “acquisition of content for simple reproduction” is described as the process of step S215.

  The digital content for simple reproduction acquired in step S215 is different from the digital content for reproduction. The digital content for simple reproduction is, for example, digital content with lower quality (image quality and sound quality) than the digital content for reproduction. The digital content for simple reproduction may be, for example, digital content that constitutes a part of the digital content for reproduction. The digital content for simple reproduction may be, for example, commercial digital content that introduces the content of the digital content for reproduction.

  In the case of passing through step S215, in step S214, the digital content for simple reproduction is reproduced. The digital content for simple playback reproduced here is lower in quality (image quality or sound quality) than the digital content for playback, is part of the digital content for playback, or is digital content for commercial use. This is not the original digital content for playback.

  After the reproduction of the designated digital content for reproduction, it is determined whether or not to end the process (step S216). In step S216, for example, when the user operation input unit 102 is operated by the user and information for ending the process is input, it is determined that the process is to be ended (step S216: Yes).

  On the other hand, in step S216, for example, when the user operation input unit 102 is operated by the user and another digital content for reproduction is designated as the digital content to be reproduced, it is determined not to end the process (step S216). (S216: No), the process proceeds to step S203.

  As described above, according to the present embodiment, data related to the manifest is associated, and only the digital content for reproduction that can be decrypted using the key data acquired based on the data related to the manifest is included. Played. In other words, the digital content for reproduction can be reproduced only when the conditions regarding the manifest and the key data are met.

  On the other hand, if the conditions for decryption using the data related to the manifest and the key data are met, the user can perform the same operation as the normal playback operation, and the designated playback digital content can be obtained. Can be played. As a result, the use of the digital content for reproduction can be restricted, and the designated digital content for reproduction can be reproduced without causing a special user to perform special consciousness and operation.

  Further, according to the present embodiment, when decrypting the digital content for reproduction, the key data is acquired by communicating with the external device 120 so that the digital content for reproduction can be reproduced. It is possible to limit the media player 100 to be able to communicate with 120. This can also limit the use of digital content for reproduction. At this time, for example, the use of the digital content for reproduction can be further restricted by requiring the media ID when acquiring the key data.

  For example, when the external device 120 is realized by a flash memory such as a memory card, the external device 120 must be mounted in a state that can be read by the media player 100 when playing back digital content for playback. Don't be. In other words, by distributing the media 110 and the external device 120 together, only the user who has been properly acquired does not have the external device 120. Can be restricted from. The distribution may be free distribution or paid distribution.

  Furthermore, according to the present embodiment, when there is no data related to the manifest stored in the medium 110, the digital content for simple reproduction is reproduced, whereby the digital content for reproduction associated with the data related to the manifest is reproduced. Differentiation between the owned user and other users can be achieved.

  At this time, as digital content for simple playback, digital content with lower quality (image quality and sound quality) than digital content for playback, digital content constituting a part of digital content for playback, and digital content for playback Although it is not digital content for playback, such as digital content for commercials that introduces the content of the content, it is expected to have the effect of inducing regular acquisition of digital content for playback by playing related digital content The Thereby, the sales promotion effect of the media 110 can be expected.

  Then, according to the recording medium in which the reproduction program of the present embodiment is recorded so as to be readable by the computer, various effects as described above can be obtained by causing the computer in the control unit 101 to execute the stored reproduction program. Can do.

  Therefore, various operations obtained by executing the above-described reproduction program are realized by causing the computer to read and execute the recorded reproduction program. As a result, various effects obtained by executing the above-described reproduction program can be obtained.

  By the way, in the present embodiment, for example, a media player 100 that reads a medium 110 that uses light when reproducing data, such as a CD (including CD-ROM, CD-RW, etc.) and a DVD. Although described, the embodiment to which the present invention is applicable is not limited to this. The playback device of the present invention can be realized by various devices capable of playing back moving image layer data and audio data, such as a video deck having the same configuration as the media player 100, for example.

  The playback method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. Further, this program may be a transmission medium that can be distributed via a network such as the Internet.

The block diagram which shows schematic structure of the media player in this Embodiment. The flowchart which shows the processing procedure of a media player.

Explanation of symbols

  100 media player, 103 reading unit, 104 MPV manifest analysis unit, 105 encrypted content decryption key acquisition unit, 106 encrypted content decryption unit, 107 playback unit, 110 media

Claims (6)

Data acquisition for acquiring the digital content for reproduction and the data related to the manifest from a medium in which the encrypted digital content for reproduction and the data related to the manifest defining the reproduction conditions of the digital content for reproduction are stored in association with each other Means,
Key data obtaining means for obtaining key data used for decrypting the digital content for reproduction obtained by the data obtaining means based on data on the manifest obtained by the data obtaining means;
Decryption means for decrypting the digital content for reproduction acquired by the data acquisition means based on the key data acquired by the key data acquisition means;
Playback means for playing back digital content for playback decrypted by the decryption means;
A playback apparatus comprising: Comprising communication means for communicating with an external device for storing key data used for decrypting the digital content for reproduction;
The playback device according to claim 1, wherein the key data acquisition unit acquires key data stored in the external device by performing communication using the communication unit. Determination means for determining the presence or absence of data relating to the manifest stored in a medium that is a target of data acquisition by the data acquisition means;
3. The reproduction means reproduces digital contents for simple reproduction different from the digital contents for reproduction when the determination means determines that there is no data related to the manifest. The playback device described in 1. Data acquisition for acquiring the digital content for reproduction and the data related to the manifest from a medium in which the encrypted digital content for reproduction and the data related to the manifest defining the reproduction conditions of the digital content for reproduction are stored in association with each other Process,
A key data obtaining step for obtaining key data used for decrypting the digital content for reproduction based on data on the manifest obtained by the data obtaining step;
A decryption step of decrypting the digital content for reproduction acquired by the data acquisition step based on the key data acquired by the key data acquisition step;
A reproduction step of reproducing the digital content for reproduction decoded by the decoding step;
A playback method comprising:   A reproduction program for causing a computer to execute the reproduction method according to claim 4. A recording medium on which the reproduction program according to claim 5 is recorded so as to be readable by a computer.

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