JP4679160B2 - Transmission device, content reproduction device, and content and license distribution system - Google Patents

Description

  The present invention relates to a content and a license distribution system that distributes content in which license data for enabling content playback is multiplexed from a transmission device, and plays back the content in the content playback device. The present invention also relates to a transmission device and a content reproduction device.

  As a conventional content and license distribution method in a content distribution system, there is a method in which a content reproduction device acquires a content and a license describing a use condition for enabling use of the content as integrated data from a content distribution server. . For example, a method for downloading content data and a license for the content from a content server as one data is disclosed (for example, see Patent Document 1).

In future content distribution, it is assumed that a certain content and another content are linked, and the content reproduction device sequentially reproduces the content according to the link. For example, it is assumed that the link source content is organized distribution real-time streaming content that is distributed at a predetermined distribution time, and the link destination content is storage-type content that has been downloaded to a content reproduction device in advance. Furthermore, it is assumed that the license of the link destination content is changed in time series as the playback time of the link source content elapses. For example, if only the first half of the link source streaming content is played back, the link destination content can be played back only once, but if the link source streaming content is played back for another 10 minutes, the link destination content is played back three times. It is assumed that there will be a demand for control that can be performed.
JP 2000-155734 A

  However, if it is assumed that the license of the storage-type content is changed according to the playback time of the real-time streaming content of the organized distribution as described above, if the conventional method is used, it depends on the playback time of the link source content. It is necessary to acquire the content with the license superimposed from the content server, and it is expected that the content acquisition requests to the content server will increase. Also, since the link source content is organized real-time streaming content, it is expected that content acquisition requests to the content server will be concentrated at a specific time. As represented by the above example, if it is assumed that the license of the link destination content is changed by the link source content regardless of whether the linked content is streaming content / accumulated content, the content acquisition requests to the content server increase. Is expected to. Accordingly, an object of the present invention is to provide a method for solving these problems.

To solve the above problems, the transmission device of the present invention, the second license acquiring means for acquiring the second license data for permitting reproduction of the second content linked to the first content, the transmission of the first content It passed the second license data for changing the use condition of the second content by time, a second license multiplexing rule acquisition for acquiring second license multiplexing rule indicating that multiplexing in the first content after the start Means, multiplexed data generating means for multiplexing the acquired second license data with the first content to generate multiplexed data, and second license multiplexing acquired by the second license multiplexing rule acquiring means Multiplexed data generation control means for controlling the multiplexed data generation means in accordance with a multiplexing rule; The serial multiplexed data, a predetermined time period, by providing a transmitting means for transmitting the streaming to a content playback device, the elapsed time from the start of transmitting the first content, to change the use conditions of the second content.

The second license multiplexing rule, the longer the elapsed time from the start of the transmission first content, a rule to allow longer playing of the second content, the multiplexed data generation control unit Controls the multiplexed data generating means so that the longer the elapsed time from the start of transmission of the first content, the second license data having a longer usage period of the second content is multiplexed with the first content. it may be used to.

Furthermore, the content playback apparatus of the present invention switches the playback to the storage type content linked to the streaming content during the playback of the streaming content, and changes the usage conditions of the storage type content according to the elapsed time after the playback of the streaming content starts. a content reproducing apparatus capable to Rukoto, the first content stream distribution type, storage type and the second by the time elapsed after the start of transmission of the first content as well as permits the reproduction of the second content Receiving means for receiving multiplexed data in which second license data for changing content usage conditions is multiplexed for a predetermined period; the second license data and the first content from the received multiplexed data Extracting means for extracting the second license data Reproduces the extracted first content, and when the second content is acquired, the reproduction is switched to obtain the acquired second content. Playback means for playing back based on the second license data.

  The content reproduction apparatus further includes a content storage unit that stores storage type content in advance, and the content acquisition unit stores the second content if the second content is stored in the content storage unit. If the second content is acquired and not stored, it may be acquired from the server via the communication network.

  Note that the present invention can be realized not only as such a content and license distribution system, but also as a single unit such as a transmission device and a content reproduction device constituting these content and license distribution systems, or these contents In addition, it can be realized as a content and license distribution method having a characteristic operation in the license distribution system as a step, or as a program that causes a general-purpose computer such as a personal computer to execute the characteristic operation and function. Needless to say, the program can be distributed via a computer-readable recording medium such as a CD-ROM or a transmission medium such as the Internet.

  As described above, according to the present invention, when the broadcast content and another storage type content are linked and the playback is switched from the link source broadcast content to the link destination storage type content, the link source broadcast content is switched to the link destination storage type. Even when content switching occurs all at the same time, a license acquisition request is sent to the license server by superimposing the link storage content license on the link source broadcast content and delivering it to the client Can be eliminated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a content and license distribution system according to the present embodiment. According to the content and license distribution system of the present invention, another storage-type content linked to the content being reproduced (corresponding to “first content” in the claims) as the broadcast content is reproduced. (This corresponds to “second content” in the scope of claims.) This is a system that can switch playback and change the development of content. Note that the content in the embodiment refers to data obtained by digitally compressing video and audio by a compression method such as MPEG-2 (Moving Picture Experts Group) or MPEG-4, and encrypting by AES, Triple DES, or the like as necessary. Point to. The digital broadcast sending apparatus 101 multiplexes the contents and licenses necessary for reproducing the contents, and sends them to the broadcasting satellite 103. In this case, generally, content and license data for enabling the reproduction of the content are multiplexed. In this embodiment, license data of another content linked to the content is also time-divisionally divided. Multiplexed. The content reproduction apparatus 102 receives the data stream from the broadcast satellite 103, separates the multiplexed data, and reproduces the content according to the license. Content is stored in the content server 105, and the content reproduction apparatus 102 acquires content data from the content server 105 through a communication network 104 such as the Internet.

  The content distribution service using this system is a service that provides an environment in which a user who has made a viewing contract in advance can play back content using the content playback device 102. All the content in this service is encrypted, and the content reproduction apparatus 102 reproduces the content after obtaining a license including the content usage conditions and the content decryption key. In this service, contents and licenses are distributed by two methods: a method using a communication network 104 such as the Internet and a method using a broadcast satellite 103. In this service, a relation between a certain content and another content is given to the content as link information, and the content reproduction apparatus 102 can specify the content to be reproduced next using the link information.

  Hereinafter, configurations of the transmission apparatus 101 and the content reproduction apparatus 102 according to the present embodiment will be described.

  FIG. 2 is a block diagram showing the configuration of the sending apparatus 101 shown in FIG. As shown in FIG. 2, the sending apparatus 101 includes a content data input unit 201, a license data input unit 202, a license multiplexing rule input unit 203, a multiplexer 204, a multiplexing control unit 205, and an output unit 206. The sending device 101 is a device that generates a data stream distributed using the broadcast satellite 103. The content data input unit 201 is a functional unit that receives input of content data encrypted in advance and a content ID for uniquely specifying the content. The license data input unit 202 is a functional unit that accepts input of license data including link information that specifies content linked from the content. The license multiplexing rule input unit 203 is a functional unit that receives an input of a rule when multiplexing content data and license data. The multiplexer 204 is a functional unit that multiplexes content data and license data to generate a data stream. The multiplexing control unit 205 is a functional unit that controls data multiplexing in the multiplexer 204. The output unit 206 is a functional unit that sends the generated data stream to the broadcast satellite 103. In addition, when a license packet is multiplexed into a content packet in time series, a timer for measuring the current time and elapsed time is necessary, but a digital broadcast transmission device is naturally provided. Therefore, illustration and description are omitted.

  Next, FIG. 3 is a block diagram illustrating an example of the configuration of the content reproduction apparatus 102. As shown in FIG. 3, the content playback apparatus 102 is a content playback apparatus that accepts input from a user and can switch playback from the content being played back to the linked content, and includes a receiving unit 301, a demultiplexer 302, a content packet processing unit 303, a content recording unit 304, a license packet processing unit 305, a license recording unit 306, a content reproduction unit 307, a work key management unit 308, a reproduction control unit 309, a communication unit 310, and a user operation input unit 311. Have. The receiving unit 301 is a functional unit that receives a data stream transmitted from the broadcast satellite 103. The demultiplexer 302 is a functional unit that separates the received data stream into content packets and license packets. The content packet processing unit 303 is a functional unit that performs data processing on the received content packet. The content recording unit 304 is a functional unit having a storage area in which content type content data is recorded. The license packet processing unit 305 is a functional unit that performs data processing on the received license packet. The license recording unit 306 is a functional unit having a storage area for recording license data. The content reproduction unit 307 is a functional unit that decodes and decodes content data and reproduces the content. The work key management unit 308 is a functional unit that holds and manages a work key for decrypting license data. The reproduction control unit 309 is a functional unit that performs reproduction control such as determination of whether or not content can be reproduced using license data. The communication unit 310 is a functional unit that communicates with the content server 105 and the like through the communication network 104. The user operation input unit 311 is a functional unit that receives operations such as content switching from the user of the content reproduction apparatus 102.

  Hereinafter, processing in the transmission apparatus 101 and the content reproduction apparatus 102 in the content distribution service using this system will be described in order.

  First, the processing up to generation and transmission of a data stream in the transmission apparatus 101 will be described using the flowchart of FIG. FIG. 4 is a flowchart showing the operation of the sending apparatus 101 shown in FIG.

  S401: Content data and content ID encrypted in advance are input to the content data input unit 201. The content ID is identification information for uniquely specifying the content.

  S402: Data including link information and license data for designating content to be linked from the content is input to the license data input unit 202. FIG. 5 is a diagram illustrating an example of data input to the license data input unit 202. Data input to the license data input unit 202 includes a license ID for uniquely specifying license data, a link destination content ID for uniquely specifying linked content, and content acquisition that is information necessary for acquiring content data. It consists of information, a content key for decrypting the content, and usage conditions for the content. The license data input unit 202 is given a plurality of data as inputs.

  In FIG. 5, two data identified by license IDs “0x1001” and “0x1002” are described as data input to the license data input unit 202. The data identified by the license ID “0x1001” includes license data for using the content with the content ID “0xAAAA”. Also, the content ID “0xAAAA” is designated as the linked content. The content data can be acquired by “ftp://xxxx.xxx.xxx/content/0xAAAAA.mpg”, the content key is “0xFF..FF (128 bits)”, and the usage condition is December 1, 2003 From December 31, 2003 to December 31, 2003, a valid period of availability is set.

  S403 in FIG. 4: A rule for multiplexing contents and licenses is input to the license multiplexing rule input unit 203. FIG. 6 is a diagram illustrating an example of a license multiplexing rule. Specifically, an example of a multiplexing rule that multiplexes two license data with the same content while shifting the time is shown. In the license multiplexing rule, the license ID of the license to which the rule is applied, the license erasure flag indicating the limit of license accumulation in the content reproduction apparatus 102 that has received the license, and the distribution start indicating the time when the license can be multiplexed and distributed Consists of time and delivery end time. The multiplexing rules for all licenses given in S402 of FIG. 4 are described and input to the license multiplexing rule input unit 203. The input license multiplexing rule is transmitted to the multiplexing control unit 205.

  FIG. 6 describes license multiplexing rules for licenses with license IDs “0x1001” and “0x1002”. This means that the license data with the license ID “0x1001” is multiplexed into a data stream transmitted between 9:00 on December 2, 2003 and 9:29:59 on December 2, 2003. Yes. The license ID “0x1001” indicates that the license erase flag of the license packet is set to “TRUE” when multiplexing. The license erasure flag is “TRUE” because, in the content reproduction apparatus 102 that has received the license data, if a content license having the same link source content exists in the content reproduction apparatus 102, the license is deleted. Otherwise, it means that the license with the license ID “0x1001” cannot be saved.

  S404 in FIG. 4: The multiplexing control unit 205 multiplexes the content and the license data using the multiplexer 204 according to the license multiplexing rule, and generates a data stream. When the license data is multiplexed, the license data is encrypted after being encrypted with a work key shared with the content reproduction apparatus 102 to be received.

S405 in FIG. 4: The generated data stream is sent from the output unit 206.
This is the end of the description of the processing in the sending apparatus 101.

  FIG. 7 is a diagram showing an example of the relationship between license data multiplexed in accordance with the multiplexing rule shown in FIG. 6 and content reproduced correspondingly. However, the content A is assumed to be streaming content by satellite broadcasting. Further, it is assumed that the contents B, C, and D are stored in the content recording unit 304 in advance. In this figure, during streaming delivery of content A, license data of content D linked to content A is multiplexed and delivered to content A for a certain period of time (between t0 and t1). It has been shown that. At this time, in the content A being played back by the content playback device 102, for example, an event that prompts the user whether to switch the content to be played back subsequently occurs, and the user plays the content A as it is. The user selects whether to continue or to switch the playback to the content D. For example, when the content A is a drama or the like, the “event that prompts the user” is an event that predicts or clearly indicates that the development of the subsequent story will change according to the user's selection.

  Here, when the user selects to switch the playback to the content D, the user operates the user operation input unit 311 to instruct the content playback device 102 to switch the playback to the content D. Thereby, the license D is extracted from the multiplexed data. However, until this time point, the content reproduction apparatus 102 has reproduced the content A according to the license A acquired in advance, and thus holds the license A in the license recording unit 306. Here, for example, when the license deletion flag “TRUE” is described in the license packet of the license D, the license recording unit 306 must delete the license A from the license recording unit 306. By erasing the license A from the license recording unit 306, the content reproduction device 102 can store the license D in the license recording unit 306 and reproduce the content D according to the license D.

  On the other hand, when the user selects to continue playback of the content A in the previous selection event, the user operates the user operation input unit 311 to instruct the content playback apparatus 102 to continue playback of the content A. Accordingly, the license recording unit 306 deletes the license D extracted from the multiplexed data, and holds the license A that was originally held. Thereby, the user can continue to view the content A according to the license A. After that, when the license C and the license B are sequentially multiplexed and distributed to the content A, the user can continue the content from the content A to another content C or B as described above. Switching can be selected.

  As described above, if an unnecessary one of the license extracted from the multiplexed data and the license held from the original is deleted each time, a series of reproduced multiple Therefore, the license recording unit 306 only needs to use a memory area for one license data, and the memory area can be used effectively.

  In the above example, it has been described that an event for inquiring the user to switch content occurs each time a new license is multiplexed. However, the present invention is not limited to this method. For example, when different licenses are multiplexed in time series during content reproduction, if a user does nothing, a new license is taken into the license recording unit 306 each time a new license is multiplexed. It is good. In this case, if the license deletion flag is “TRUE”, the already held license may be deleted and a new license may be stored in the license recording unit 306.

  Next, a description will be given of processing for switching from data stream reception to content playback and playback to linked content in the content playback apparatus 102.

  The processing from the reproduction start request from the user to the content reproduction start in the content reproduction apparatus 102 will be described using the flowchart of FIG. FIG. 8 is a flowchart showing the operation of the content reproduction apparatus 102 shown in FIG.

  A content reproduction process is started when a content reproduction start request is input from the user to the user operation input unit 311. At the start of content reproduction, the user designates the channel identifier of the channel to which the content to be reproduced is distributed, and inputs a content reproduction start request.

  S701: A content reproduction start request is transmitted from the user operation input unit 311 together with a channel identifier. The playback control unit 309 requests the receiving unit 301 to receive a data stream corresponding to the designated channel identifier. The receiving unit 301 receives a data stream corresponding to the designated channel identifier.

  S702: The received data stream is sent from the receiving unit 301 to the demultiplexer 302 and separated into a content packet and a license packet. The data stream received by this service includes a content packet and a license packet. The structure of the content packet and the license packet will be described with reference to FIGS. 9 and 10, respectively.

  FIG. 9 is a diagram illustrating an example of the data structure of the content packet. The content packet includes a packet identifier, a channel identifier, a content ID, and content data. The packet identifier indicates the type of the packet, and an identifier indicating a content packet is described here. The channel identifier indicates which channel the content is. The content ID indicates an identifier for specifying the encrypted content included in the packet. The content data contains encrypted content data. This completes the description of the structure of the content packet.

  Next, FIG. 10 is a diagram illustrating an example of the data structure of the license packet. The license packet includes a packet identifier, a channel identifier, a work key identifier, a link source content ID, a link destination content ID, link destination content acquisition information, a license deletion flag, and license data. The packet identifier indicates the type of the packet, and here, an identifier indicating a license packet is described. The channel identifier indicates the identifier of the channel to which the license is distributed. The work key identifier is information indicating with which work key the license is encrypted. The work key is a key that is distributed to all users who have contracted to receive content distribution in the system in advance, and is distributed in a broadcast wave for distributing personal information or the like by satellite digital broadcasting, for example. The link source content ID and the link destination content ID are identifiers for uniquely specifying the content of the link source and the link destination, respectively. In this case, the content ID of the content included in the content packet multiplexed as the data stream of the same channel is described in the link source content ID. The two pieces of information indicate a link relationship between contents, and indicate that a link is established from the content specified by the link destination content ID to the content specified by the link source content ID. The link destination content acquisition information indicates the acquisition destination of the content data specified by the link destination content ID. The license erasure flag is information indicating restrictions on license accumulation in the content reproduction apparatus 102. When the license erasure flag is “TRUE”, if a license for content having the same link source content exists in the content reproduction device 102, the license must be deleted after the license accumulated in the content reproduction device 102 is deleted. This flag means that it cannot be saved. When the license deletion flag is “FALSE”, it indicates that there is no restriction on the recording of the license. The license data is composed of usage conditions of the content and a content key, and is encrypted with a work key. This completes the description of the structure of the license packet.

  S703 in FIG. 8: The content packet separated from the data stream is transmitted to the content packet processing unit 303. The content packet processing unit 303 extracts the content ID from the acquired content data and transmits it to the reproduction control unit 309. Further, the content data extracted from the content packet is transmitted to the content reproduction unit 307.

  The process of transmitting the content packet from the reception of the data stream to the content reproduction unit 307 in S701 to S703 in FIG. 8 continues until the reproduction of the content is completed.

  S704 in FIG. 8: The reproduction control unit 309 acquires the usage condition and the content key of the content from the license recording unit 306 using the acquired content ID. It is assumed that content reproduction apparatus 102 has acquired a license for reproducing real-time streaming content of organized distribution in advance and records it in license recording unit 304. An example of data managed by the license recording unit 304 is shown in FIG. The content recording management unit 304 manages the available content ID, link source content ID, license ID, content acquisition information, usage conditions, and content key information for each license. The above information is collectively called license information. The usable content ID is an identifier for uniquely identifying content that can be reproduced with the license. The link source content ID is an identifier for uniquely identifying the link source content when the content is linked. The content acquisition information indicates the acquisition destination of the content data of the content. The use condition indicates a condition that must be satisfied when the content is reproduced. The content key indicates a decryption key for the content.

  FIG. 11 shows that licenses for using the content IDs “0xAAAA” and “0xBBBB” are recorded. The license with content ID “0xBBBB” will be described. The content ID “0xBBBB” is linked from the content ID “0x2222”. The license with the content ID “0xBBBB” is the license ID “0x2002”, no usage condition is set, and the content key is “0xAA ... AA (128 bits)”. In addition, the content ID “0xBBBB” is broadcast as organized streaming content on the channel identifier “0x01” from 13:00 on December 24, 2003 to 15:00 on the same day. In the example shown in FIG. 7, the content with the usable content ID “0xBBBB” is the content D, and the content with the link source content ID “0x2222” is the content A. The license with the license ID “0x2002” is the license D shown in FIG. 7, and the content with the link source content ID “0x2222” between t0 (2003/12/01) and t1 (2003/12/31). Multiplexed to A and distributed. Then, after the license A for reproducing the content A is erased from the license recording unit 306, it is the same as that stored in the license recording unit 306 as a new license A.

  S705 in FIG. 8: The playback control unit 309 evaluates the usage conditions of the acquired content and determines whether the content can be played back. If it is determined that reproduction is possible, the content key is transmitted to the content reproduction unit 307, and if necessary, the content use condition is updated, and the process proceeds to S706 in FIG. For example, when the number of reproductions is set in the use condition, the license update means updating to a value obtained by subtracting 1 from the value described in the current license information. When it is determined that reproduction is impossible, the user is notified that the content cannot be reproduced, and the process ends.

  S706 in FIG. 8: The content reproduction unit 307 decrypts the content data using the content key and reproduces the content.

  The processing from the reproduction start request from the user to the content reproduction start in the content reproduction apparatus 102 has been described above.

Next, processing during playback in the content playback apparatus 102 will be described.
With reference to the flowchart in FIG. 12, processing during content reproduction in the content reproduction apparatus 102 will be described. FIG. 12 is a flowchart showing an operation during content reproduction in the content reproduction apparatus shown in FIG.

  S1101: The receiving unit receives the data stream of the channel and transmits it to the demultiplexer 302.

  S1102: The demultiplexer 302 separates the data stream into content packets and license packets.

  S1103: Depending on the type of the separated packet, the content packet is transmitted to the content packet processing unit 303, and the license packet is transmitted to the license packet processing unit 305. The content reproduction (S1109) and the license decryption (S1104) are performed. I do.

  S1104: Having acquired the license packet, the license packet processing unit 305 acquires a work key from the work key management unit 308 using the work key identifier in the license packet. Data managed by the work key management unit 308 will be described later. The license packet processing unit 305 decrypts the license in the license data using the work key acquired from the work key management unit 308, and transmits it to the license recording unit 306. The content reproduction apparatus 102 obtains in advance a work key necessary for the license by a secure communication method that is not wiretapped / falsified by a third party through broadcasting or the Internet.

  Data managed by the work key management unit 308 will be described. An example of data managed by the work key management unit 308 is shown in FIG. The work key management unit manages a work key identifier, which is an identifier for uniquely specifying a work key, and actual data of the work key. FIG. 13 shows that two work keys are managed. The data of the work key identifier “0x1234” will be described. The actual data of the work key identifier “0x1234” is “0x1111 ... 1111 (128 bits)”. This is the end of the description of the data managed by the work key management unit.

  S1105 in FIG. 12: The license packet processing unit 305 confirms the license deletion flag in the license packet. If the license deletion flag is TURE, the process of S1106 in FIG. 12 is performed. If the license deletion flag is FALSE, the process of S1107 in FIG. 12 is performed.

  S1106 in FIG. 12: When a license with the same link source content ID as the link source content ID in the license packet acquired in S1104 in FIG. 12 exists in the license recording unit 306, the license in the license recording unit 306 is deleted.

  S1107 in FIG. 12: The license decrypted in S1104 in FIG. 12 is recorded in the license recording unit 306.

  S1108 in FIG. 12: The user is notified that the link destination of the content has been updated, and the process ends.

  S1109 in FIG. 12: The content packet processing unit 303 extracts content data from the acquired content packet and transmits the content data to the content reproduction unit 307. The content playback unit 307 decodes the received content data and continues playback.

This is the end of the description of the processing in the content reproduction apparatus 102 during content reproduction.
Next, processing for switching to playback of linked content using link information from the content being played back will be described. In the following example, the license is when the license deletion flag is FALSE, and the license for reproducing the link destination content multiplexed on the content is stored in the license recording unit 306 at the time of distribution.

  Processing in the content reproduction apparatus 102 when switching to reproduction of linked content will be described using the flowchart of FIG. FIG. 14 is a flowchart showing an operation at the time of switching the content reproduction of the content reproduction apparatus shown in FIG.

  In the content reproduction apparatus 102, a reproduction request for the link destination content is input from the user to the user operation input unit 311 during reproduction of the link source content.

  A reproduction content switching process is started when a reproduction request for content linked from the content being reproduced is input to the user operation input unit 311. The user designates the content ID of the content to be reproduced when starting the reproduction of the linked content.

  S1301: The user operation input unit 311 transmits a content reproduction request to the reproduction control unit 309 together with the content ID designated by the user. The playback control unit 309 transmits the received content ID to the license recording unit 306, and acquires license information regarding the designated content from the license recording unit 306.

  S1302: The playback control unit 309 evaluates the usage conditions of the license acquired from the license recording unit 306, and determines whether playback is possible. If it is determined that playback is possible, the content key is transmitted to the content playback unit 307, and the process of S1303 is performed. When it is determined that the reproduction is impossible, the user is notified that the use condition is not satisfied, and the process is terminated.

  S1303: If the linked content is a storage type content, the playback control unit 307 checks whether the content data is in the content recording unit 304. An example of data managed by the content recording unit 304 is shown in FIG. The content recording unit 304 manages content IDs and content data. FIG. 15 shows that two pieces of content data are managed, and the content IDs are “0xAAAA” and “0xZZZZ”. If the content data exists in the content recording unit 304, the processing of S1305 is performed. If the content data does not exist in the content recording unit 304, and if the linked content is organized streaming content, the process of S1304 is performed.

  S1304: The reproduction control unit 309 acquires content data with reference to “content acquisition information” in the license information acquired from the license recording unit 306.

  When the linked content is storage-type content, content data is acquired from the content server 105 through the communication unit 310 and recorded in the content recording unit 304.

  When the link destination content is organized streaming content, the reception unit 301 is requested to specify the channel identifier and receive the data stream. After receiving the data stream, the content data is transmitted to the content reproduction unit 307 via the demultiplexer 302 and the content packet processing unit 303.

  S1305: When the linked content is a storage-type content, the playback control unit 309 causes the content recording unit 304 to transmit the content data to the content playback unit 307.

  When the linked content is organized streaming content, the reception unit 301 transmits the content data to the content reproduction unit 307 via the demultiplexer 302 and the content packet processing unit 303 after receiving the data stream.

  The content reproduction unit 307 decrypts the content data using the content key and reproduces the content.

  This is the end of the description of the process of switching to playback of linked content using link information from the content being played back.

  In addition, although the example in which another content is sequentially linked to one multi-story content has been described above, another multi-story content is linked to each linked content as another example below. The case will be described with reference to FIG. 16, FIG. 17, and FIG. FIG. 16 is a diagram showing another example of the relationship between license data multiplexed in accordance with a multiplexing rule and content reproduced correspondingly. FIG. 17A is a diagram illustrating an example of a video reproduced at time T0 to T1 of the content A. For example, when a woman goes hiking, a large dragonfly is approaching. However, as shown in FIG. 16, at time T1 to T2, a license (LT) B that enables playback of content B is multiplexed and distributed. FIG. 17B is a diagram illustrating an example of a display prompting input of what to do if the woman who appears in the content A is a user. Thus, at time T1 to T2, in conjunction with the delivery of LT B, a screen asking the user whether to select switching to content B is displayed. For the user: 1. Do you catch a dragonfly? It is expressed to select one of the two. Further, this display does not need to display a screen of only characters as shown in FIG. 17B, and may be guided by voice or displayed in telop as the screen progresses. Here, for example, if “2. I will give you” in FIG. 17B is selected to switch to the content B, the LT A in the license recording unit 306 is deleted, LT B is acquired, and playback is switched to content B. When the user selects switching to the content B, if the license deletion flag is TRUE, the license A in the license recording unit 306 for reproducing the content A is deleted, so that the user who has selected switching to the content B is The content A cannot be reproduced again.

  FIG. 17C is a diagram illustrating an example of a video when content B is played back until time T2 after LT B is acquired. For example, the image is a dragonfly trying to fly. Furthermore, to the content B, the LTC that enables the reproduction of the content C is multiplexed and distributed from time T2 to T3. FIG. 17D is a diagram illustrating an example of a display prompting the user to input. For the user: 1. Stop following the dragonfly or It is expressed to choose one to follow. Here, for example, if “2. Follow” in FIG. 17D is selected to select switching to the content C, LT B in the license recording unit 306 is deleted and the LTC is changed. Acquired and playback is switched to content C.

  FIG. 18A is a diagram illustrating an example of a video when content C is reproduced until time T3 after acquiring LTC. For example, when you talk about dragonflies, you can see that you met a classmate at university. The contents C are distributed with the LTD that enables the reproduction of the contents D from time T3 to time T4. FIG. 18B is a diagram showing still another example of a display prompting the user to input. For the user: Stop drinking tea with him, or 2. It is expressed to choose between going to drink tea together. Here, for example, if “2. Go to drinking tea” in FIG. 18B is selected to switch to the content D, the LTC in the license recording unit 306 is deleted. LTD is acquired and playback is switched to content D.

  FIG. 18C is a diagram illustrating an example of a video when the content D is reproduced to the end after acquiring the LTD. For example, if you go to a cup of tea with a classmate at the university, you will get to know each other, get married, and then your child will be born and have fun with the child in the park. FIG. 18D is a diagram illustrating an example of a video when content B is reproduced to the end after acquiring LT B. That is, in this example, the user selects “1. Stop following the registration marks” on the screen of FIG. FIG. 18D shows, for example, an image of a woman going home from hiking and having fun playing with a dog.

  In the above description, the case where there is some relationship between linked contents has been described by taking multi-story contents with different developments and endings as an example. However, the contents of the present invention are multi-story contents. There is no limitation, and the contents may not be related to each other. For example, for a user who has played content that the company wants to commercial for 10 minutes or more, another popular content that is linked can be played back 30 minutes more than a user with a playback time of less than 10 minutes. Alternatively, it may be multiplexed with the link source content according to the playback time of the link source content.

  Note that the content usage conditions in FIG. 5 describe the valid period during which the content can be played and the number of times the content is played. In addition to this, the maximum playable time, the region code of the playback device, etc. You may describe the restrictions regarding the reproduction | regeneration of a content.

  In S1304 of FIG. 14, when acquiring storage-type content, the data acquired from the content server 105 may be composed of a content packet and a license packet of content different from the content distribution data. . When the license packet is attached to the data acquired from the content server 105, the communication unit 310 transmits the received data to the demultiplexer 302 in S1304 of FIG. The demultiplexer 302 separates the received data and transmits the content packet to the content packet processing unit 303 and the license packet to the license packet processing unit 305, respectively. Processing subsequent to transmission to the license packet processing unit 305 performs the same processing as S1104 in FIG. The content packet processing unit 303 extracts content data and records it in the content recording unit 304. After the processing for the content packet and the license packet is completed, the processing after S1305 in FIG. 14 is continued.

  The content distribution method of the present invention is useful as a digital content distribution method and the like. The content reproduction apparatus of the present invention is useful as a personal computer having a digital broadcast receiving function and a communication function, a PDA (Personal Digital Assistant), a mobile phone, an STB (Set Top Box), and the like. The transmission device of the present invention is useful as a transmission device or server of a broadcast station that distributes content and licenses to a content reproduction device via a communication network such as a satellite broadcast network or the Internet.

It is a figure which shows schematic structure of the content and license delivery system which concerns on this Embodiment. It is a block diagram which shows the structure of the sending apparatus shown in FIG. It is a block diagram which shows an example of a structure of a content reproduction apparatus. It is a flowchart which shows operation | movement of the sending apparatus shown in FIG. It is a figure which shows an example of the data input into a license data input part. It is a figure which shows an example of a license multiplexing rule. It is a figure which shows an example of the relationship between the license data multiplexed according to the multiplexing rule shown in FIG. 6, and the content reproduced | regenerated corresponding to it. It is a flowchart which shows operation | movement of the content reproduction apparatus shown in FIG. It is a figure which shows an example of the data structure of a content packet. It is a figure which shows an example of the data structure of a license packet. It is a figure which shows an example of the license data which the license recording part shown in FIG. 3 manages. 4 is a flowchart illustrating an operation during content reproduction in the content reproduction apparatus illustrated in FIG. 3. It is a figure which shows an example of the work key data managed by the work key management part shown in FIG. FIG. 4 is a flowchart showing an operation at the time of switching content reproduction of the content reproduction device shown in FIG. 3. FIG. It is a figure which shows an example of the content data which the content recording part shown in FIG. 3 manages. It is a figure which shows the other example of the relationship between the license data multiplexed according to the multiplexing rule, and the content reproduced | regenerated corresponding to it. (A) is a figure which shows an example of the image | video reproduced | regenerated by the time T0-T1 of the content A. FIG. (B) is a figure which shows an example of the display which prompts the input of what to do if the woman who appeared in the content A is a user. (C) is a figure which shows an example of the image | video in case content B is reproduced | regenerated until time T2 after acquisition of LT B. FIG. (D) is a figure which shows an example of the display which prompts a user's input. (A) is a figure showing an example of a picture in case contents C are reproduced until time T3 after acquiring LTC. (B) is a figure showing other examples of a display which prompts a user's input. (C) is a figure which shows an example of the image | video when the content D is reproduced | regenerated to the last after acquisition of LTD. (D) is a figure which shows an example of the image | video when the content B is reproduced | regenerated to the end after acquisition of LT B. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Transmission apparatus 102 Content reproduction apparatus 103 Broadcasting satellite 104 Communication network 105 Content server 201 Content data input part 202 License data input part 203 License multiplexing rule input part 204 Multiplexer 205 Multiplexing control part 206 Output part 301 Receiving part 302 Demultiplexer 303 Content packet processing unit 304 Content recording unit 305 License packet processing unit 306 License recording unit 307 Content playback unit 308 Work key management unit 309 Playback control unit 311 User operation input unit

Claims (11)

Second license acquisition means for acquiring second license data permitting reproduction of the second content linked to the first content;
The acquiring the second license data, a second license multiplexing rule indicating that multiplexing in the first content to change the use conditions of the second content with the passage time from the start of transmitting the first content Two license multiplexing rule acquisition means;
Multiplexed data generating means for multiplexing the acquired second license data with the first content to generate multiplexed data;
Multiplexed data generation control means for controlling the multiplexed data generation means in accordance with a second license multiplexing rule acquired by the second license multiplexing rule acquisition means;
Transmission means for transmitting the generated multiplexed data to the content reproduction apparatus by streaming for a predetermined period of time, so that the use condition of the second content can be set according to the elapsed time from the start of transmission of the first content. Change the sending device. The second license multiplexing rule multiplexes the second license data permitting the reproduction of the second content for a longer time as the elapsed time from the start of transmission of the first content is longer . A rule to
The multiplexed data generation control means is configured to multiplex the second license data having a longer usage period of the second content with the first content as the elapsed time from the start of transmission of the first content is longer. The transmission apparatus according to claim 1, wherein the multiplexed data generation means is controlled. This is a content playback device that can switch playback to storage-type content linked to streaming content during playback of streaming content and change the usage conditions of storage-type content according to the elapsed time from the start of playback of streaming content. And
Second license data for permitting the reproduction of the storage-type second content to the stream distribution-type first content and changing the usage condition of the second content according to the elapsed time from the start of transmission of the first content, Receiving means for receiving multiplexed data multiplexed for a predetermined period;
Extraction means for extracting the second license data and the first content from the received multiplexed data;
Content acquisition means for acquiring the second content whose reproduction is permitted by the extracted second license data;
Content comprising: playback means for playing back the extracted first content and switching the playback when the second content is acquired, and playing back the acquired second content based on the second license data Playback device. The content playback device further includes:
It has content storage means for storing storable content in advance,
The content acquisition unit acquires the stored second content if the second content is stored in the content storage unit, and acquires the second content from a server via a communication network if the second content is not stored. Item 4. The content playback device according to Item 3. A content and license distribution system comprising a transmission device and a content reproduction device,
The transmitter is
Second license acquisition means for acquiring second license data permitting reproduction of the second content linked to the first content;
Second license multiplexing rule acquisition means for acquiring a second license multiplexing rule for multiplexing the second license data with the first content;
Multiplexed data generating means for multiplexing the acquired second license data with the first content to generate multiplexed data;
Multiplexed data generation control means for controlling the multiplexed data generation means in accordance with a second license multiplexing rule acquired by the second license multiplexing rule acquisition means;
Transmission means for transmitting the generated multiplexed data to the content reproduction device by streaming for a predetermined period,
The content playback device
The transmission device permits the storage-type second content to be reproduced within the predetermined period, and changes the use condition of the second content according to an elapsed time from the start of transmission of the first content. Receiving means for receiving multiplexed data in which two license data are multiplexed;
Extracting means for extracting the second license data and the first content from the received multiplexed data;
Content acquisition means for acquiring second content for which reproduction is permitted by the extracted second license data;
Content is provided with reproduction means for reproducing the extracted first content and switching the reproduction when the second content is acquired, and reproducing the acquired second content based on the second license data And license distribution system. A second license acquisition step of acquiring second license data permitting reproduction of the second content linked to the first content;
The acquiring the second license data, a second license multiplexing rule indicating that multiplexing in the first content to change the use conditions of the second content with the passage time from the start of transmitting the first content 2 license multiplexing rule acquisition step;
A multiplexed data generation step of multiplexing the acquired second license data with the first content to generate multiplexed data;
A multiplexed data generation control step of controlling the multiplexed data generation means according to the second license multiplexing rule acquired by the second license multiplexing rule acquisition means;
A transmission step of transmitting the generated multiplexed data to the content reproduction device by streaming for a predetermined period of time, so that a use condition of the second content is set according to an elapsed time after the transmission of the first content is started. Change the sending method. This is a content playback method that can switch playback to storage-type content linked to streaming content during playback of streaming content and change the usage conditions of storage-type content according to the elapsed time from the start of playback of streaming content. And
Second license data for permitting the reproduction of the storage-type second content to the stream distribution-type first content and changing the usage condition of the second content according to the elapsed time from the start of transmission of the first content, A receiving step of receiving multiplexed data multiplexed for a predetermined period;
An extraction step of extracting the second license data and the first content from the received multiplexed data;
A content acquisition step of acquiring second content for which the extracted second license data permits reproduction;
Playing back the extracted first content and switching the playback when the second content is acquired, and playing back the acquired second content based on the second license data Playback method. A program for a transmission device,
A second license acquisition step of acquiring second license data permitting reproduction of the second content linked to the first content; and a second license multiplexing rule for multiplexing the second license data into the first content A second license multiplexing rule acquisition step of acquiring, a multiplexed data generation step of multiplexing the acquired second license data with the first content to generate multiplexed data, and the second license multiplexing In accordance with the second license multiplexing rule acquired by the rule acquisition means, a multiplexed data generation control step for controlling the multiplexed data generation means, and the generated multiplexed data is streamed to the content reproduction apparatus by streaming for a predetermined period. A program that causes a computer to execute a transmission step Beam. A content playback apparatus capable of switching playback to storage-type content linked to streaming content during playback of the streaming content and changing usage conditions of the storage-type content according to the elapsed time from the start of playback of the streaming content The program of
Second license data for permitting the reproduction of the storage-type second content to the stream distribution-type first content and changing the usage condition of the second content according to the elapsed time from the start of transmission of the first content, A reception step of receiving multiplexed data multiplexed for a predetermined period, an extraction step of extracting the second license data and the first content from the received multiplexed data, and the extracted first A content acquisition step of acquiring second content permitted to be reproduced by two license data; and reproducing the extracted first content. When the second content is acquired, the reproduction is switched to obtain the first content A reproduction step of reproducing two contents based on the second license data. Grams.   A second license acquisition step of acquiring second license data permitting reproduction of the second content linked to the first content; and a second license multiplexing rule for multiplexing the second license data into the first content A second license multiplexing rule acquisition step of acquiring, a multiplexed data generation step of multiplexing the acquired second license data with the first content to generate multiplexed data, and the second license multiplexing In accordance with the second license multiplexing rule acquired by the rule acquisition means, a multiplexed data generation control step for controlling the multiplexed data generation means, and the generated multiplexed data is streamed to the content reproduction apparatus by streaming for a predetermined period. A program that causes a computer to execute a transmission step A computer-readable recording medium beam.   Second license data for permitting the reproduction of the storage-type second content to the stream distribution-type first content and changing the usage condition of the second content according to the elapsed time from the start of transmission of the first content, A reception step of receiving multiplexed data multiplexed for a predetermined period, an extraction step of extracting the second license data and the first content from the received multiplexed data, and the extracted first A content acquisition step of acquiring second content permitted to be reproduced by two license data; and reproducing the extracted first content. When the second content is acquired, the reproduction is switched to obtain the first content A reproduction step of reproducing two contents based on the second license data. Computer readable recording medium recording a gram.

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