JP5338774B2 - Distribution system, information processing apparatus, information processing program, and content input method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distribution system capable of efficiently operating contents distributed from a distribution device which does not belong to an overlay network, while storing the contents in a distributed manner over the overlay network, an information processing apparatus, an information processing program and a content loading method. <P>SOLUTION: An information processing apparatus includes a first information processing apparatus which is participated in an overlay network in a steady manner, and a second information processing apparatus which is different from the first information processing apparatus, and the second information processing apparatus acquires second contents from a distribution device storing the second contents different from first contents which are distributed by a distribution system in a steady manner. In the case where the acquired second contents meet a loading condition for loading the second contents to the overlay network, the second information processing apparatus then loads the second contents to the overlay network as contents which can be acquired on the overlay network. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a technical field of a Peer to Peer (P2P) type distribution system including a plurality of node devices that can communicate with each other via a network.

  In recent years, a peer-to-peer distribution system has been known. In a peer-to-peer distribution system, a plurality of content data are distributed and stored in a plurality of node devices participating in an overlay network composed of a plurality of node devices. In the overlay network, the node device can acquire content data from other node devices. The content data is hereinafter referred to as “content”. Further, the node device is hereinafter referred to as “node”. In such a peer-to-peer distribution system, it is possible to reduce the load concentration on the server as in the client-server distribution system. Further, the location of the content distributed and stored in the overlay network can be efficiently searched using a distributed hash table as disclosed in, for example, Patent Document 1.

JP 2006-197400 A

  By the way, for example, content distributed by a client / server type distribution system or the like may be newly input to an overlay network in a peer-to-peer type distribution system. Here, “content input” means that new content is stored in the node as content that can be acquired by the overlay network. Further, the content to be input is determined by a request from a provider or a viewer of this content, for example. However, when all the contents to be input are input to the overlay network, they cannot be stored in the storage of the node that stores these contents. Therefore, there is a possibility that it may hinder the storage and distribution of content such as karaoke data that is regularly used in the distribution system.

  In addition, for example, in the case of a peer-to-peer distribution system in which nodes frequently participate in or leave the overlay network, the number of nodes that store content in the overlay network may be reduced. In this case, the total storage capacity that is the sum of the storage capacities of all nodes is reduced. For this reason, it may be difficult to efficiently operate a peer-to-peer distribution system by distributing and storing all contents.

  Accordingly, the present invention has been made in view of the above points and the like, and a distribution system and an information processing apparatus that can efficiently operate by distributing and storing content distributed from a distribution device in an overlay network It is an object to provide an information processing program and a content input method.

  In order to solve the above-described problem, the invention according to claim 1 is an overlay network composed of a plurality of information processing devices that can communicate with each other via a network, and the information processing device acquires content from other information processing devices. In the distribution system configured to, the information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus. And the content includes first content that is regularly distributed by the distribution system and second content that is different from the first content, and the second information processing device includes the first content Acquisition means for acquiring the second content from the distribution device storing the second content, and the second acquired by the acquisition means A determination unit that determines whether or not the content satisfies the input condition to be input to the overlay network, and the determination unit determines that the input condition is satisfied, the second content is converted to the overlay content. And control means for executing control for putting the content into the overlay network as content obtainable on the network.

  According to a second aspect of the present invention, in the distribution system according to the first aspect, the distribution system includes an input server that inputs the first content into the overlay network, and the input server includes the first server. A transmission unit configured to transmit content to the first information processing apparatus, wherein the first information processing apparatus includes a reception unit configured to receive the first content transmitted from the input server; Storage means for storing the first content as content obtainable by the overlay network.

  According to a third aspect of the present invention, in the distribution system according to the first or second aspect, the second information processing device searches for the location of the second content stored in the information processing device in the overlay network. Search means for acquiring the second content from the distribution apparatus when the search means cannot find the second content.

  According to a fourth aspect of the present invention, in the distribution system according to any one of the first to third aspects, the second information processing apparatus obtains information indicating a degree of popularity of the second content. 2 acquisition means, wherein the determination means determines that the input condition is satisfied when the popularity of the second content is equal to or higher than a predetermined popularity.

  According to a fifth aspect of the present invention, in the distribution system according to any one of the first to fourth aspects, the distribution device is an information processing device that participates in the overlay network or other information that does not participate in the overlay network. A second receiving unit configured to receive the second content transmitted from the processing device; and the second content when the received second content satisfies a censorship criterion for distribution from the distribution device. Is stored as content that can be distributed from the distribution device.

  According to a sixth aspect of the present invention, in the distribution system according to any one of the first to fifth aspects, the information processing apparatus that stores the first content and the second content is the first content. It further comprises a deletion means for deleting the second content with priority.

  According to a seventh aspect of the present invention, in the distribution system according to any one of the first to sixth aspects, the distribution system includes a management server that manages input of the content, and the second information processing apparatus. Is a receiving means for receiving, from a Web browser, a location information extracted from a Web page transmitted from a Web server and including a location information indicating the location of the second content stored in the distribution device And the control means transmits the location information included in the received request to the management server, and the management server receives the location information transmitted from the information processing apparatus. A third acquisition unit configured to acquire the second content from the distribution device based on the information; and Characterized in that it comprises a dosing means put into the lay network.

  The invention according to claim 8 is the distribution system according to any one of claims 1 to 7, wherein the second content is an information processing apparatus that participates in the overlay network or another that does not participate in the overlay network. The content is input from an information processing device or posted.

  The invention according to claim 9 is a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses capable of communicating with each other via a network. The information processing apparatus includes: a first information processing apparatus that regularly participates in the overlay network; and a second information processing apparatus that is different from the first information processing apparatus. The content includes a first content that is regularly distributed by the distribution system and a second content that is different from the first content, and the second information processing apparatus includes: An acquisition unit that acquires the second content from a distribution device that stores the second content, and a second acquired by the acquisition unit A determination unit that determines whether or not the content satisfies the input condition to be input to the overlay network, and the determination unit determines that the input condition is satisfied, the second content is converted to the overlay content. And control means for executing control for putting the content into the overlay network as content obtainable on the network.

  The invention according to claim 10 is a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses that can communicate with each other via a network. The information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus. There is first content that is regularly distributed by a distribution system, and second content that is different from the first content, and the second content is transferred to a computer included in the second information processing apparatus. The step of acquiring the second content from a stored distribution device, and the acquired second content are: A step of determining whether or not an input condition to be input to the overlay network is satisfied; and when the input condition is determined to satisfy the input condition, the second content is set as content that can be acquired by the overlay network. And an information processing program for executing a step of executing control for entering the network.

  The invention according to claim 11 is a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses capable of communicating with each other via a network. The information input device includes: a first information processing device that regularly participates in the overlay network; and a second information processing device different from the first information processing device, The content includes first content that is regularly distributed by the distribution system and second content that is different from the first content, and the content input method stores the second content. Acquiring the second content from the distribution device, and the acquired second content Determining whether or not an input condition to be input to the overlay network is satisfied, and if it is determined that the input condition is satisfied, the second content is set as content that can be acquired by the overlay network. And executing a control for inputting to the overlay network.

  According to the invention described in claims 1, 8 to 11, when the second content distributed from the distribution device is input to the overlay network, the second content is input to the overlay network only when the second content satisfies the input condition. Is done. Therefore, the distribution system can be efficiently operated by distributing and storing the second content in the overlay network in which the first content is regularly distributed.

  According to the second aspect of the present invention, it is possible to efficiently input the first content separately from the second content to the overlay network.

  According to the third aspect of the present invention, the second content that is not stored in the information processing apparatus in the overlay network can be efficiently input to the overlay network.

  According to the fourth aspect of the present invention, since the second content with high popularity that can be distributed from the distribution device is distributed over the overlay network, the processing load on the distribution device can be reduced.

  According to the invention described in claim 5, it is possible to prevent inappropriate second content from being input to the overlay network.

  According to the sixth aspect of the present invention, it is possible to prevent the use of the first content from being hindered by the overlay network due to the presence of the second content.

  According to the seventh aspect of the present invention, the management server can reduce the processing load of the second information processing apparatus by inputting the second content.

It is a figure showing an example of outline composition of a contents distribution system concerning this embodiment. (A) is a block diagram showing a schematic configuration example of a Web server WS. (B) is a block diagram showing a schematic configuration example of the management server MS. (C) is a diagram illustrating a schematic configuration example of a router Rm. (D) is a block diagram showing a schematic configuration example of a user terminal UT. It is a sequence diagram which shows the process etc. of each apparatus in the content delivery system S when a sub content is thrown in.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a content distribution system.

[ 1. Content distribution system configuration and operation overview ]
First, with reference to FIG. 1, the structure and operation | movement outline | summary of the content delivery system concerning this embodiment are demonstrated. FIG. 1 is a diagram illustrating a schematic configuration example of a content distribution system according to the present embodiment. As shown in FIG. 1, the content distribution system S according to the present embodiment includes a Web server WS, a management server MS, an input server DS, a user terminal UT, and a router Rm (m = 1, 2, 3,... J). Etc. The Web server WS, management server MS, input server DS, user terminal UT, and router Rm are connected to the network NW. The network NW is composed of the Internet or the like. The Web server WS is a server for configuring a moving image distribution site that publishes a moving image file posted by a contributor on the network NW. The Web server WS is an example of a distribution device according to the present invention. The management server MS is a server for monitoring the access status to the video file registered in the video distribution site and the load status of the Web server WS. The input server DS is a server that inputs karaoke data to an overlay network ON to be described later. The user terminal UT is, for example, a personal computer or a mobile device used by the user. For example, the user terminal UT can be connected to the network NW using an IP address assigned by a server (not shown) of an Internet service provider. In the example of FIG. 1, one user terminal UT is shown, but actually there exists for each of a plurality of users.

  In addition, as shown in FIG. 1, in the content distribution system S, a base network NLm is constructed for each of a plurality of bases Pm. An example of this base is a karaoke store, for example. The base network NLm is a private network such as a LAN (Local Area Network). Also, a router Rm and a plurality of base terminals Tm-l (l = 1, 2, 3) are connected to each base network NLm. The router Rm is a relay device that relays IP (Internet Protocol) packets between the network NW and the base network NLm. The base terminal Tm-l is installed in a karaoke store, for example, and can reproduce karaoke data.

  Note that the viewing terminal Tm-l at each site Pm is not limited to communicating with only the router Rm connected to the same site network NLm. For example, the viewing terminal T1-1 at the site P1 can communicate not only with the router R1 connected to the same site network NL1, but also with the router R2 and the like at other sites P2 and the Web server WS.

  As shown in FIG. 1, in the content distribution system S, an overlay network ON is configured by participation of a plurality of nodes Nn (n = 1, 2, 3,... K) that can communicate with each other via the network NW. Has been. The overlay network ON is a logical network that forms a virtual link. The overlay network ON is realized by a specific algorithm, for example, an algorithm using a distributed hash table. The distributed hash table is hereinafter referred to as “DHT (Distributed Hash Table)”. Here, participating in the overlay network ON means operating in a state where various messages can be transmitted / received to / from other nodes Nn via the overlay network ON based on a routing table using DHT. Note that a routing table using DHT is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  In this embodiment, the router Rm and the user terminal UT can participate in the overlay network ON as the node Nn. The router Rm is a node Nn that regularly participates in the overlay network ON. The node Nn that regularly participates in the overlay network ON is hereinafter referred to as a “resident node”. The resident node is an example of the first information processing apparatus in the present invention. Here, “steady participation” means, for example, that the node Nn participates without leaving the overlay network ON at the time of failure or other than maintenance. In the present embodiment, a program for executing control processing as the node Nn is installed in the router Rm. In addition to each base Pm, a program that executes control processing as the node Nn may be installed in a device that is always connected to the network in each home. On the other hand, the user terminal UT is a node Nn that does not necessarily regularly participate in the overlay network ON. The node Nn that does not always participate in the overlay network ON is hereinafter referred to as a “general node”. The general node is an example of the “second information processing apparatus different from the first information processing apparatus” in the present invention. Here, the user terminal UT participates in the overlay network ON for a predetermined time, for example, when the user uses the user terminal UT.

  A node ID is assigned to each node Nn participating in the overlay network ON. This node ID is unique identification information for identifying the node Nn from among the nodes Nn participating in the overlay network ON. In addition, various contents with different contents are distributed and stored in the plurality of nodes Nn participating in the overlay network ON. The content includes first content that is regularly distributed by the content distribution system S and second content that is different from the first content. The second content is content that is input or posted from a node Nn that participates in the overlay network ON or another information processing device that does not participate in the overlay network ON. In the following description, “first content” is referred to as main content. The “second content” is referred to as sub-content. An example of main content is karaoke data. Karaoke data is used at the base terminal Tm-l of each base Pm. An example of sub-content is a moving image file registered in a moving image distribution site. This moving image file is mainly distributed from the Web server WS. In the present embodiment, the Web server WS does not belong to the overlay network ON. Note that belonging indicates that the Web server WS participates in the overlay network ON. However, for example, a popular video file is distributed from a resident node using the overlay network ON. This is to reduce the processing load on the Web server WS. In this case, the resident node functions as an edge server. Note that another example of the sub-content includes a predetermined data file uploaded by the user terminal UT or the like, for example.

  A content ID is assigned to each content stored in each node Nn when the overlay network is ON. The content ID is unique identification information for identifying the content from the content stored in the node Nn when the overlay network is ON. Note that the node ID and the content ID are generated by, for example, a hash function common to the overlay network ON.

  Here, the node Nn that stores the content is hereinafter referred to as a “content holding node”. Information indicating the location of the content is stored as index information in the node Nn that manages the location of the content. The node Nn that manages the location of the content is hereinafter referred to as a “root node”. The index information includes a set of the node information of the content holding node storing the content and the content ID of the content. The node information includes, for example, the IP address, port number, and node ID of the content holding node. For example, the root node is determined to be the node Nn to which the node ID closest to the content ID is assigned. The node ID closest to the content ID is, for example, the node ID with the highest number of upper digits that match.

  A certain node Nn may acquire predetermined content from the content holding node via the overlay network ON. As an example of this case, there is a case where the node N1 that has received a request for a predetermined main content from the base terminal T1-1 has not stored the main content. In the example of FIG. 1, the node N1 is the router R1. In this case, the node N1 first performs a search process for searching for the location of a predetermined main content stored in the content holding node in the overlay network ON. Here, the predetermined main content is, for example, karaoke data selected as an acquisition target by the user of the base terminal T1-1. The predetermined main content is hereinafter referred to as “acquisition main content”. The node N1 that performs the search process is hereinafter referred to as a “user node”. The search process is performed based on the content ID of the main content to be acquired. Specifically, the user node generates a content location inquiry message in the search process. The content location inquiry message is a message for inquiring the location of the main content to be acquired to the root node. Further, the content location inquiry message includes the IP address and port number of the user node that transmits this message, and the content ID of the main content to be acquired. Then, the user node transmits the generated content location inquiry message to the root node by DHT routing. The DHT routing is known in, for example, Japanese Patent Application Laid-Open No. 2007-053662, and detailed description thereof is omitted. The root node that has received the content location inquiry message acquires index information corresponding to the content ID included in the content location inquiry message. Then, the root node returns the acquired index information to the user node. The index information returned in this way includes the IP addresses of one or more content holding nodes that store the main content to be acquired. Thus, the user node receives the index information from the root node. With this index information, the user node can find the main content to be acquired. Then, the user node accesses the content holding node based on the IP address of the content holding node included in the received index information. Then, the user node requests the main content to be acquired from the content holding node, and acquires the main content from the content holding node. Then, the user node transmits the acquired main content to the base terminal T1-1.

  Another example of the case where the user node acquires the predetermined content is a case where the node Nn that has received a request for the predetermined sub-content from the user terminal UT has not stored the sub-content. In this case, the node Nn first performs a search process for searching for the location of a predetermined sub-content stored in the content holding node in the overlay network ON. Here, the predetermined sub-content is, for example, a moving image file selected as an acquisition target by the user of the user terminal UT. Hereinafter, the predetermined sub-content is referred to as “sub-content to be acquired”. Also in this case, the user node performs search processing for searching for the location of the sub-content to be acquired from the overlay network ON, as in the case of the main content described above. Then, the user node acquires the sub content found by acquiring the index information from the root node from the content holding node. The user node transmits the sub content acquired from the content holding node to the user terminal UT.

  By the way, the user node may not be able to find the sub-content to be acquired from the overlay network ON by the search process. As an example in this case, there is a case where the sub-content to be acquired is not put into the overlay network ON. In this case, the node information of the content holding node of the sub-content to be acquired is not stored in the root node that has received the content location inquiry message. Therefore, the root node returns a content no message to the user node. This content non-message is a message indicating that there is no content holding node storing the sub-content to be acquired. This content no message is transmitted from the user node to the user terminal UT. If the sub-content to be acquired cannot be found from the overlay network ON, the user terminal UT acquires the sub-content from the Web server WS that stores the sub-content. In this way, when the sub-content acquired from the Web server WS satisfies the input condition for input to the overlay network ON, this sub-content is input to the overlay network ON. Thereby, the sub-content acquired from the Web server WS becomes content that can be acquired by overlay network ON. The charging conditions will be described later.

[ 2. Configuration and function of Web server WS ]
Next, the configuration and functions of the Web server WS will be described with reference to FIG. FIG. 2A is a block diagram illustrating a schematic configuration example of the Web server WS. As shown in FIG. 2A, the Web server WS includes a control unit 1, a storage unit 2, a communication unit 3, and the like. The control unit 1, the storage unit 2, and the communication unit 3 are connected to each other via a bus 4. An IP address is assigned to the web server WS. The Web server WS may be composed of a plurality of servers such as an application server and a database server.

  The storage unit 2 is composed of, for example, a hard disk drive. The storage unit 2 stores an operating system, a server program, and the like. In the content storage area provided in the storage unit 2, a moving image file registered in the moving image distribution site is stored in a predetermined file format. The moving image file may include not only moving image data but also audio data, for example. Examples of moving image files include wma files, wmv files, asf files, and the like.

  The storage unit 2 stores Web pages that can be provided to the user terminal UT and the like. The Web page is composed of a structured document file described in HTML (Hyper Text Markup Language), XML, or the like. In the Web page, an identifier of a player that is software for reproducing a moving image file is described. Furthermore, location information indicating the location of a moving image file that can be provided to the user terminal UT or the like is described in the Web page. An example of the location information is a URL (Uniform Resource Locator) of a moving image file. This URL includes the file path of the moving image file. The file path of the moving image file is information for specifying the position of the content storage area. The Web page may be configured such that the URL of the metafile of the moving image file is described as location information. The metafile of the moving image file is a text file for the Web browser to access the moving image file from the Web page. Therefore, the URL of the moving image file is described in the meta file of the moving image file. Examples of a metafile of a moving image file include a wax file, a wvx file, an asx file, and the like. By using such a metafile of a moving image file, the Web browser starts the player indicated on the Web page, and the moving image file can be streamed.

  The communication unit 3 performs communication control with the router Rm, the user terminal UT, the management server MS, or the like through the network NW.

  The control unit 1 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 1 is an example of a second receiving unit and a second storage unit in the present invention. The control unit 1 performs processing as the Web server WS when the CPU reads and executes a program stored in the storage unit 2 or the like.

  The moving image file posted by the contributor is made public on the moving image distribution site after being censored by the control unit 1. Specifically, the control unit 1 receives a moving image file transmitted from the user terminal UT that has accessed the moving image distribution site via the network NW, for example. That is, the moving image file is uploaded from the user terminal UT to the Web server WS. Then, the control unit 1 registers the received moving image file as the content to be released on the moving image distribution site when it satisfies the release standard necessary for being released on the moving image distribution site. The public standard is an example of a censorship standard for distribution from the Web server WS. Here, it is assumed that a moving image file including contents inappropriate to be released does not satisfy the release standard. The censorship of whether or not the public standard is satisfied is performed by the control unit 1 referring to the public standard data set in advance. Note that this censorship may be configured to be performed visually by an administrator.

[ 3. Configuration and function of management server MS ]
Next, the configuration and function of the management server MS will be described with reference to FIG. FIG. 2B is a block diagram illustrating a schematic configuration example of the management server MS. As shown in FIG. 2B, the management server MS includes a control unit 11, a storage unit 12, a communication unit 13, and the like. The control unit 11, the storage unit 12, and the communication unit 13 are connected to each other via a bus 14. An IP address is assigned to the management server MS.

  The storage unit 12 is composed of, for example, a hard disk drive. The storage unit 12 stores an operating system, a server program, and the like. In addition, the storage unit 12 stores the IP address and port number of the Web server WS and node information of a predetermined number of resident nodes participating in the overlay network ON. The node information of the resident node is provided to the user terminal UT in response to a request from the user terminal UT.

  The communication unit 13 performs communication control with the user terminal UT or the web server WS through the network NW.

  The control unit 11 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 11 is an example of third acquisition means and input means in the present invention. The control unit 11 performs processing as the management server MS when the CPU reads and executes a program stored in the storage unit 12 or the like.

[ 4. Configuration and function of router Rm ]
Next, the configuration and function of the router Rm will be described with reference to FIG. FIG. 2C is a diagram illustrating a schematic configuration example of the router Rm. As shown in FIG. 2C, the router Rm includes a control unit 21, a storage unit 22, a communication unit 23a, a communication unit 23b, and the like. The control unit 21, the storage unit 22, the communication unit 23 a, and the communication unit 23 b are connected to each other via a bus 24. Each router Rm is assigned an IP address.

  The storage unit 22 is composed of, for example, a hard disk drive. The storage unit 22 stores an operating system, an IP packet relay processing program, a node processing program, and the like. The node processing program or the like may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the node processing program or the like may be recorded on a recording medium and read via a drive of the recording medium, for example.

  In addition, the storage unit 22 stores a routing table using DHT used for overlay network ON. In the content storage area provided in the storage unit 22, karaoke data is stored as main content. The karaoke data is stored as a file with a file name corresponding to a song number, for example. The karaoke data includes audio data, caption data, and video data. Furthermore, a moving image file distributed from the Web server WS may be stored as a sub-content in the content storage area provided in the storage unit 22. The contents stored in the storage unit 22 are given date information indicating the stored date. The date may include time.

  The communication unit 23a performs communication control with another router Rm, the user terminal UT, the management server MS, or the like through the network NW. The communication unit 23b performs communication control with the base terminal Tm-l through the base network NLm.

  The control unit 21 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 21 is an example of a receiving unit, a storing unit, and a deleting unit in the present invention. The control unit 21 operates as the IP packet relay processing unit 21a when the CPU executes the IP packet relay processing program stored in the storage unit 22 or the like. The IP packet relay processing unit 21a performs processing for relaying IP packets from other routers or hosts in the network layer, which is the third layer of the OSI (Open Systems Interconnection) reference model. Since the function of the IP packet relay processing unit 21a is the same as that of a known router or L3 switching hub, detailed description is omitted. Further, the control unit 21 operates as the node processing unit 21b by the execution of the node processing program stored in the storage unit 22 or the like by the CPU. The processing of the IP packet relay processing unit 21a and the node processing unit 21b is executed by a single CPU by multitasking or multicore. Alternatively, the processing of the IP packet relay processing unit 21a and the node processing unit 21b may be configured to be executed by two CPUs using two CPUs.

[ 5. Configuration and function of user terminal UT ]
Next, the configuration and function of the user terminal UT will be described with reference to FIG. FIG. 2D is a block diagram illustrating a schematic configuration example of the user terminal UT. 2D, the user terminal UT includes a control unit 31, a storage unit 32, a buffer memory 33, a decoder unit 34, a video processing unit 35, a display unit 36, an audio processing unit 37, a speaker 38, and a communication unit. 39, an input unit 39a, and the like. The control unit 31, the storage unit 32, the buffer memory 33, the decoder unit 34, the video processing unit 35, the display unit 36, the audio processing unit 37, the communication unit 39, and the input unit 39a are connected to each other via a bus 39b. Yes.

  The storage unit 32 is composed of, for example, a hard disk drive. The storage unit 32 stores an operating system, a web browser program, a player program, a node processing program, and the like. The node processing program or the like may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the node processing program or the like may be recorded on a recording medium and read via a drive of the recording medium, for example.

  In addition, the storage unit 32 stores the IP address and port number of the Web server WS and the IP address and port number of the management server MS. Further, the storage unit 32 of the user terminals UT participating in the overlay network ON stores a routing table using DHT.

  The buffer memory 33 buffers the received content. The decoder unit 34 performs decoding processing such as data expansion and decoding of video data and audio data included in the content. The video processing unit 35 performs a predetermined drawing process on the video data decoded by the decoder unit 34 and reproduces and outputs it as a video signal. The display unit 36 displays video or the like on the display based on the video signal reproduced and output from the video processing unit 35. The display unit 36 displays the image decoded by the decoder unit 34. The audio processing unit 37 performs D (Digital) / A (Analog) conversion of the audio data decoded by the decoder unit 34 into an analog audio signal, and then amplifies this by an amplifier to reproduce and output. The speaker 38 outputs the audio signal reproduced and output from the audio processing unit 37 as a sound wave.

  The communication unit 39 performs communication control with the Web server WS, the management server MS, or the router Rm through the network NW.

  The control unit 31 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 31 is an example of a search unit, an acquisition unit, a second acquisition unit, a reception unit, a determination unit, a deletion unit, and a control unit in the present invention. The control unit 31 has a clock function and a timer function. In addition, the control unit 31 operates as the Web browser 31a when the CPU executes a Web browser program stored in the storage unit 32 or the like. The web page acquired from the web server WS by the web browser 31a is displayed on the display. In addition, the control unit 31 operates as the player 31b when the CPU executes the player program stored in the storage unit 32 or the like. The player 31b controls the decoder unit 34 and the like to reproduce the content. In addition, the control unit 31 operates as the node processing unit 31c when the CPU executes a node processing program stored in the storage unit 32 or the like. Further, the node processing unit 31c has a relay function for relaying between the Web browser 31a and the Web server WS. With this relay function, a request from the Web browser 31a is transferred to the Web server WS via the node processing unit 31c. Also, with this relay function, the response from the Web server WS is transferred to the Web browser 31a via the node processing unit 31c.

  Note that the processing of the web browser 31a and the node processing unit 31c is executed by one CPU by multitasking or multicore. Alternatively, the processing of the web browser 31a and the node processing unit 31c may be configured to be executed by two CPUs using two CPUs.

[6. Operation of Content Distribution System S]
Next, the operation of the content distribution system S according to the present embodiment will be described.

(6.1 Karaoke data input operation)
First, the operation of the content distribution system S when karaoke data is input as main content to the overlay network ON will be described.

  For example, when new karaoke data is uploaded from the system operator's terminal to the input server DS, the input server DS acquires the node information of the resident node from the management server MS. Then, the input server DS accesses the resident node based on the IP address and port number included in the acquired node information, and transmits a content storage request message. This content storage request message is a message for requesting storage of karaoke data. The input server DS may acquire node information of a plurality of resident nodes from the management server MS. In this case, the input server DS transmits a content storage request message to each resident node.

  Then, the node processing unit 21b of the resident node that has received the content storage request message returns a content storage permission message, for example, when there is a free space for storing karaoke data in the storage unit 22 of the resident node. This content storage permission message is a message permitting storage of karaoke data. On the other hand, there may be no free space for storing karaoke data in the storage unit 22 of the resident node that has received the content storage request message. In this case, the node processing unit 21b of the resident node deletes the content selected from the plurality of contents stored in the storage unit 22. For example, the oldest content is selected and deleted. The oldest content means content with the oldest stored date. Here, when the main content and the sub content are included in the plurality of contents, the node processing unit 21b of the resident node deletes the sub content with priority over the main content. Thereby, it can be avoided that the use of the main content is hindered by the overlay network ON due to the presence of the sub-content. It should be noted that the content deletion when there is no free space is performed in the same manner when the resident node acquires new content from another node Nn via the overlay network ON. Thus, when an empty area for storing karaoke data is secured by deleting the content, the node processing unit 21b of the resident node returns a content storage permission message to the input server DS. When receiving the content storage permission message from the resident node, the input server DS transmits karaoke data to the resident node.

  Thus, the resident node that has received the karaoke data stores this karaoke data as the main content and becomes a content holding node. The resident node that stores the main content performs publishing processing of the main content. This publishing process is a process for disclosing that this content is stored to other nodes Nn. In this publishing process, the node processing unit 21b of the resident node generates a publish message. The publish message includes the content ID of the main content and the node information of the resident node that stores the main content. Then, the resident node transmits the generated publish message to the root node of the main content by DHT routing. The root node that has received the publish message stores a set of the content ID of the main content and the IP address of the resident node as index information.

  As described above, karaoke data is input to the overlay network ON as main content that can be acquired by the overlay network ON.

(6.2 Movie file input operation)
Next, with reference to FIG. 3, the operation of the content distribution system S when a moving image file is input to the overlay network ON as sub-content will be described. FIG. 3 is a sequence diagram showing processing of each device in the content distribution system S when sub-content is input.

  It is assumed that the node processing unit 31c of the user terminal UT has acquired the node information of the resident node from the management server MS as a premise of the moving image file input operation. In addition, it is assumed that the Web page received from the Web server WS by the Web browser 31a is displayed on the display unit 36 of the user terminal UT. This Web page is a page for viewing a video file published on a video distribution site. In addition, this Web page includes, for example, a URL of a moving image file or a URL of a meta file of the moving image file.

  In the state where the Web page is displayed, for example, when a user of the user terminal UT gives an instruction to play a moving image file via the input unit 19a, the Web browser 31a of the user terminal UT requests the moving image file to be acquired. Is transmitted to the node processing unit 31c (step S1). Alternatively, a request for a moving image file to be acquired may be transmitted to the node processing unit 31c on condition that the Web browser 31a has received a Web page. This request is, for example, an HTTP (HyperText Transfer Protocol) request. The request for the moving image file includes the URL of the moving image file extracted from the Web page. In some cases, the URL of the metafile of the moving image file is included in the Web page. In this case, the Web browser 31a first acquires the metafile of the moving image file and extracts the URL of the moving image file from the metafile. Then, the Web browser 31a transmits a request including the URL of the extracted moving image file to the node processing unit 31c.

  Next, when receiving the request from the Web browser 31a, the node processing unit 31c of the user terminal UT generates a content ID of the sub content based on the URL of the moving image file included in the request (Step S2). Here, the content ID is generated, for example, by hashing the URL of the moving image file with the same hash function as that for generating the node ID. In this case, the hash value of the URL of the moving image file is the content ID. The content ID may be generated such that a combination of the URL of the moving image file and information such as a keyword of the moving image file is hashed by the hash function. As described above, since the content ID is generated based on the URL of the moving image file, it is not necessary to change the description of the Web page in order to describe the content ID of the sub-content input to the overlay network ON. That is, a contributor or the like of a moving image file only needs to create a Web page on the assumption that the moving image file is distributed by a client-server type distribution system. Therefore, it does not require specialized knowledge for publishing a moving image file with the overlay network ON.

  The node processing unit 31c of the user terminal UT may be configured to acquire a content ID corresponding to the URL of the moving image file from a predetermined server such as the management server MS. In this case, the node processing unit 31c of the user terminal UT transmits the URL of the moving image file to the management server MS, for example. Then, the management server MS generates a content ID based on the URL received from the user terminal UT and returns it to the user terminal UT. Alternatively, the management server MS acquires the content ID stored in association with the URL received from the user terminal UT, and sends it back to the user terminal UT. In addition, the node processing unit 31c of the user terminal UT may include the URL of the metafile of the moving image file in the received request. In this case, the content ID of the sub content may be generated based on the URL of the metafile of the moving image file.

  Next, the node processing unit 31c of the user terminal UT accesses the resident node based on the IP address and the port number included in the node information of the resident node acquired from the management server MS, and transmits a content request message (step S3). . This content request message is a message for requesting sub-contents from the resident node. Further, the content request message includes the content ID generated in step S2.

  The content request message may be configured to include the URL of the moving image file instead of the content ID. In this case, the node processing unit 21b of the resident node generates the content ID of the sub content based on the URL of the moving image file.

  Next, the node processing unit 21b of the resident node receives the content request message from the user terminal UT. Then, the node processing unit 21b of the resident node executes search processing for searching for the location of the sub-content to be acquired based on the content ID included in the received content request message (step S4).

  Next, the node processing unit 21b of the resident node determines whether or not the acquisition target sub-content has been found from the overlay network ON by the search processing in step S4 (step S5). When the node processing unit 21b of the resident node has found the sub-content to be acquired (step S5: YES), the process proceeds to step S6. Note that the sub-content to be acquired may be found from the storage unit 22 of the resident node that has performed the search process in step S4. On the other hand, if the node processing unit 21b of the resident node cannot find the sub-content to be acquired (step S5: NO), the process proceeds to step S9.

  In step S6, the node processing unit 21b of the resident node acquires the sub-content to be acquired from the content holding node indicated by the index information received from the root node by the search process. Alternatively, the node processing unit 21 b of the resident node acquires the sub content to be acquired from the storage unit 22. Then, the node processing unit 21b of the resident node transmits the acquired sub content to the user terminal UT (step S7).

  Next, when receiving the sub-content from the resident node, the node processing unit 31c of the user terminal UT transfers this sub-content to the web browser 31a (step S8). Here, the web browser 31a activates the player 31b corresponding to the player identifier described in the web page. Then, the sub-content transferred from the node processing unit 31c is reproduced by the player 31b.

  On the other hand, in step S9, the node processing unit 21b of the resident node transmits a content no message to the user terminal UT.

  Next, when receiving the no content message from the resident node, the node processing unit 31c of the user terminal UT transfers the request received from the Web browser 31a in Step S2 to the Web server WS (Step S10). Thereby, the node processing unit 31c of the user terminal UT acquires a moving image file from the Web server WS (step S11). Then, the node processing unit 31c transfers the moving image file acquired from the Web server WS to the Web browser 31a (Step S12).

  By the way, as another example of the above steps S10 and S11, the node processing unit 31c of the user terminal UT may be configured to acquire a moving image file from a node constituting another overlay network different from the overlay network ON. . Another overlay network is constituted by, for example, a plurality of user terminals UT. In this case, the node processing unit 31c of the user terminal UT stores in advance the IP address and port number of a node participating in another overlay network. Alternatively, the IP address and port number of any node participating in another overlay network may be acquired from a predetermined server. Then, the node processing unit 31c of the user terminal UT acquires a moving image file from a node participating in another overlay network.

  Next, the node processing unit 31c of the user terminal UT transmits an access status inquiry message to the management server MS (step S13). This access status inquiry message is a message for inquiring the management server MS about the access status to the moving image file. The access status inquiry message includes, for example, the URL of a moving image file. Note that the node processing unit 31c of the user terminal UT may be configured to transmit a load status inquiry message to the management server MS. This load status inquiry message is a message for inquiring the management server MS about the load status of the Web server WS.

  Next, the control unit 11 of the management server MS receives an access status inquiry message from the user terminal UT. And the control part 11 of management server MS acquires the information which shows the access condition to a moving image file from Web server WS (step S14). This moving image file is specified from the URL included in the received access status inquiry message. Here, the information indicating the access status includes information indicating the degree of popularity of the identified moving image file. The popularity of the moving image file is calculated based on, for example, the number of accesses to the moving image file in a predetermined period. For example, the number of accesses to a moving image file in a predetermined period is calculated as the popularity of the moving image file. Alternatively, a value obtained by multiplying the number of accesses to the moving image file in a predetermined period by a predetermined coefficient is calculated as the popularity of the moving image file. The number of accesses to the moving image file in the predetermined period can be obtained, for example, when the Web server WS counts the number of requests for the moving image file from the user terminal UT or the like. Note that the popularity of the moving image file may be calculated based on, for example, the number of distributed moving image files in a predetermined period. The number of moving image files distributed in the predetermined period is obtained, for example, when the Web server WS counts the number of moving image files distributed to the user terminal UT or the like. Further, the degree of popularity of the video file may be calculated based on, for example, the total number of evaluation points given by the viewer to the video file, or the total number of favorite registrations of the video file by the viewer. Good. Information on the evaluation score and favorite registration is stored in the Web server WS.

  Note that the control unit 11 of the management server MS may receive a load status inquiry message from the user terminal UT. In this case, the control unit 11 of the management server MS acquires information indicating the load status of the Web server WS from the Web server WS. Here, the information indicating the load status includes information indicating the load factor of the Web server WS. The load factor of the Web server WS is obtained as, for example, a CPU usage rate during a predetermined period. Further, the information indicating the load status may be configured to include information indicating the occupation ratio of the bandwidth of the communication line to which the Web server WS is connected.

  Next, the control unit 11 of the management server MS transmits an answer message to the user terminal UT (step S15). This answer message is a message indicating an answer to the access status inquiry message. Further, the answer message includes information indicating the access status acquired from the Web server WS or information indicating the load status.

  Next, when the node processing unit 31c of the user terminal UT receives the reply message from the management server MS, the node processing unit 31c determines whether or not the moving image file acquired in step S11 satisfies the input condition for inputting to the overlay network ON. (Step S16). For example, when information indicating the access status is included in the answer message, information indicating the popularity of the moving image file is acquired from the information indicating the access status. In this case, the node processing unit 31c determines that the input condition is satisfied when the popularity of the acquired moving image file is equal to or higher than a predetermined popularity. As a result, a highly popular video file can be input to the overlay network ON as a sub-content. Therefore, for example, the processing load of the Web server WS can be reduced. Here, the “predetermined popularity” is defined in advance by a node processing program, for example. Also, for example, when information indicating the load status is included in the reply message, information indicating the load rate of the Web server WS or the occupation rate of the bandwidth of the communication line is acquired from the information indicating the load status. In this case, the node processing unit 31c determines that the input condition is satisfied when the acquired load factor of the Web server WS is equal to or greater than a predetermined load factor. Alternatively, the node processing unit 31c determines that the input condition is satisfied when the occupation ratio of the communication line band is equal to or greater than a predetermined occupation ratio. Thereby, for example, the processing load of the Web server WS can be reduced. Here, the “predetermined load factor” or the “predetermined occupation rate” is defined in advance by, for example, a node processing program. The node processing unit 31c is configured to determine that the input condition is satisfied when the popularity degree of the moving image file is equal to or higher than a predetermined popularity level and the load factor of the Web server WS is equal to or higher than the predetermined load factor. May be. Alternatively, the node processing unit 31c determines that the input condition is satisfied when the popularity degree of the moving image file is equal to or higher than the predetermined popularity level and the occupation rate of the bandwidth of the communication line is equal to or higher than the predetermined occupation rate. It may be configured. According to these configurations, for example, the processing load of the Web server WS can be further reduced.

  Note that it is determined whether or not the popularity of the moving image file is greater than or equal to a predetermined popularity, whether or not the load factor of the Web server WS is greater than or equal to a predetermined load factor, or the occupation rate of the communication line bandwidth It may be configured such that the control unit 11 of the management server MS determines whether or not it is equal to or greater than a predetermined occupation ratio. In this case, the reply message transmitted from the control unit 11 of the management server MS to the user terminal UT includes information indicating a determination result such as popularity. Then, the node processing unit 31c of the user terminal UT determines whether or not the moving image file acquired in step S11 satisfies the input condition for input to the overlay network ON based on the information indicating the determination result such as popularity. To do. For example, when the reply message includes information indicating that the popularity degree of the moving image file is equal to or higher than a predetermined popularity degree, the node processing unit 31c determines that the input condition is satisfied.

  In addition, you may comprise so that "the file size of a moving image file is more than predetermined file size" may be added to the input conditions mentioned above. In this case, the node processing unit 31c of the user terminal UT acquires information indicating the file size of the moving image file acquired in step S11 from, for example, the operating system. The node processing unit 31c determines that the input condition is satisfied when the file size of the moving image file is equal to or larger than the predetermined file size and the popularity level of the moving image file is equal to or larger than the predetermined popularity level. According to this configuration, a video file having a large file size and high popularity can be input to the overlay network ON. Therefore, for example, the processing load of the Web server WS can be further reduced. Here, the “predetermined file size” is defined in advance by a node processing program, for example. By using this input condition, a moving image file whose file size is a predetermined size or more can be input to the overlay network ON. Therefore, for example, the processing load of the Web server WS can be reduced. Alternatively, the node processing unit 31c is configured to determine that the input condition is satisfied when the file size of the moving image file is equal to or larger than the predetermined file size and the load factor of the Web server WS is equal to or larger than the predetermined load factor. May be. Alternatively, the node processing unit 31c determines that the input condition is satisfied when the file size of the moving image file is equal to or larger than the predetermined file size and the bandwidth occupation ratio of the communication line is equal to or larger than the predetermined occupation ratio. It may be configured. Even with these configurations, for example, the processing load of the Web server WS can be further reduced.

  Furthermore, you may comprise so that "it should be a censored moving image file" to the input conditions mentioned above. In this case, the moving image file acquired in step S11 is a moving image file censored by the control unit 1 of the Web server WS. Therefore, the node processing unit 31c determines that the input condition is satisfied when the moving image file is acquired from the Web server WS and the popularity of the moving image file is equal to or higher than a predetermined popularity. Alternatively, the node processing unit 31c is configured to determine that the input condition is satisfied when the moving image file is acquired from the Web server WS and the load factor of the Web server WS is equal to or greater than a predetermined load factor. May be. Alternatively, the node processing unit 31c determines that the input condition is satisfied when the moving image file is acquired from the Web server WS and the bandwidth occupancy of the communication line is equal to or greater than a predetermined occupancy. It may be configured. According to these configurations, inappropriate moving image content can be prevented from being input to the overlay network ON.

  When the node processing unit 31c of the user terminal UT determines that the input condition is satisfied (step S16: YES), the process proceeds to step S17. On the other hand, when it is determined that the input condition is not satisfied (step S16: NO), the node processing unit 31c does not input the moving image content.

  In step S17, the node processing unit 31c of the user terminal UT transmits a participation message to the resident node. This resident node is the node Nn that has transmitted the content-less message in step S9. The participation message is a message requesting participation in the overlay network ON.

  Next, the node processing unit 21b of the resident node receives the participation message from the user terminal UT. Then, the node processing unit 21b of the resident node acquires a predetermined number of node information from the routing table using the DHT stored in the storage unit 22 (step S18). The node processing unit 21b of the resident node transmits the acquired node information to the user terminal UT (step S19). The node processing unit 21b of the resident node may transfer the received participation message to another resident node. In this case, node information is transmitted from the plurality of resident nodes to the user terminal UT.

  Next, when receiving the node information from the resident node, the node processing unit 31c of the user terminal UT generates a routing table using the DHT in which the received node information is registered (Step S20). The user terminal UT that has generated the DHT routing table in this way participates in the overlay network ON as a general node. Since a method for generating a DHT routing table at the time of participation processing is publicly known, detailed description thereof is omitted.

  Next, the node processing unit 31c of the user terminal UT executes input control for inputting the moving image file acquired in step S11 to the overlay network ON (step S21). In this input control, first, the node processing unit 31c acquires the IP addresses and port numbers of a predetermined number of nodes Nn to which the moving image file is input from the IP addresses and port numbers stored in the storage unit 32. . For example, the IP address and port number of the node Nn that is the input destination of the moving image file are acquired from the IP address and port number registered in the routing table using DHT. Further, history information of message transmission / reception performed by the node processing unit 31c with another node Nn via the overlay network ON may be stored in the storage unit 32. When the history information includes the IP address and port number of another node Nn, the IP address and port number of the node Nn that is the input destination of the moving image file may be acquired from this. . Then, the node processing unit 31c of the user terminal UT accesses the node Nn based on each acquired IP address and port number, and transmits a content storage request message. This content storage request message is a message for requesting storage of a moving image file. The node Nn that has received the content storage request message returns a content storage permission message when, for example, there is a free area for storing the moving image file in the storage unit of the node Nn. This content storage permission message is a message permitting storage of a moving image file. On the other hand, the node Nn that has received the content storage request message returns a content storage rejection message when, for example, there is no free space for storing the moving image file in the storage unit of the node Nn. This content saving rejection message is a message for rejecting saving of the moving image file. When the node processing unit 31c of the user terminal UT receives the content storage permission message, the moving image file is transmitted to the node Nn that has transmitted the content storage permission message.

  Thus, the node Nn that has received the moving image file stores the moving image file as sub-contents and becomes a content holding node. Further, the node Nn that stores the sub-content performs a publishing process of the sub-content. The flow of the publishing process is the same as that of the main content publishing process.

  When the moving image file is input as described above, the node processing unit 31c of the user terminal UT executes a withdrawal process for leaving the overlay network ON (step S22). In this withdrawal process, the node processing unit 31c of the user terminal UT erases the DHT routing table generated in step S20 and ends the execution of the node processing program. That is, the user terminal UT participates in the overlay network ON only when the acquired moving image file is input. Thus, since the time during which the user terminal UT participates in the overlay network ON is short, the user terminal UT can be made difficult to become a content holding node or a root node. Therefore, the overlay network ON can be stably operated.

  Note that the node processing unit 31c of the user terminal UT may be configured not to be a content holding node or a root node while the overlay network is ON. For example, the node processing unit 31c of the user terminal UT can be configured not to function as a content holding node if the publishing process is not performed even when the content is stored. Further, the node processing unit 31c of the user terminal UT can be prevented from functioning as a root node if the reception of the publish message and the content location inquiry message transmitted from another node Nn is rejected.

  As described above, according to the above-described embodiment, when a moving image file distributed from a distribution device that does not belong to the overlay network ON is input to the overlay network ON as a sub-content, the sub-content satisfies the input condition. As long as the overlay network is turned on. For this reason, it is possible to avoid troubles in the storage and distribution of the main content used as the main in the overlay network ON. In addition, it is possible to avoid that the total storage capacity that is the sum of the storage capacities of the resident nodes participating in the overlay network ON is reduced more than necessary for storing the sub-contents. Therefore, the content distribution system S can be efficiently operated by distributing and storing the sub-contents in the overlay network ON where the main content is regularly distributed.

  Further, after the sub-content is input to the overlay network ON, it is possible to reduce the processing load of a distribution device such as the Web server WS that distributes the content. Furthermore, a distribution device such as the Web server WS can be efficiently used as a content pool. Here, the content pool refers to a device that can always respond to a request for acquiring content in the overlay network ON, for example. In the overlay network according to the conventional method, it is necessary to install a dedicated device as a content pool. However, in this embodiment, a distribution device such as the Web server WS can play the role. Therefore, in this embodiment, since it is not necessary to install a dedicated device as in the conventional method, the system can be made more efficient.

  In addition, for example, sub-contents whose popularity is higher than a predetermined value depending on the input conditions are distributed by overlay network ON. Therefore, it is possible to reduce the processing load on the distribution device such as the Web server WS. On the other hand, sub-contents with low popularity are distributed by the Web server WS. Therefore, the overlay network ON can be stably operated.

  Here, as another example of the input control in step S21, a case where the node processing unit 31c of the user terminal UT causes the management server MS to input a moving image file will be described. In this case, in step S10, the node processing unit 31c of the user terminal UT transmits the URL of the moving image file included in the request received in step S2 to the management server MS. Then, when receiving the URL of the moving image file transmitted from the user terminal UT, the control unit 11 of the management server MS acquires the moving image file corresponding to this URL from the Web server WS. Note that the management server MS may be configured to acquire a moving image file from a node constituting another overlay network, in the same manner as the method described in another example of step S11. Then, the control unit 11 of the management server MS inputs the acquired moving image file to the overlay network ON. For example, the control unit 11 of the management server MS acquires the IP addresses and port numbers of a predetermined number of nodes Nn to which the moving image file is input from the IP addresses and port numbers stored in the storage unit 12. Then, the control unit 11 of the management server MS accesses the node Nn based on each acquired IP address and port number, and transmits a content storage request message. The subsequent operation is the same as when the node processing unit 31c of the user terminal UT transmits a content storage request message.

  As described above, the management server MS inputs the moving image file, so that the user terminal UT does not have to participate in the overlay network ON. For this reason, the node processing unit 31c of the user terminal UT does not have to perform the processes in steps S13 to S22. And the management server MS can reduce the processing load on the user terminal UT by inputting the moving image file. Further, when the management server MS inputs a moving image file, the possibility that the power is turned off during the input is lower than that of the user terminal UT. Therefore, the moving image file can be input to the overlay network ON more reliably than when the user terminal UT inputs. In addition, when the management server MS inputs the moving image file, the input moving image file can be collectively managed by the management server MS. For this reason, it is possible to avoid putting duplicate moving image files into the overlay network ON. In addition, when the user terminal UT performs streaming playback while acquiring a moving image file from the Web server WS, special playback such as seek playback or skip playback may be performed according to a user instruction. In this case, the data portion of the moving image file during a period such as seek playback or skip playback is not acquired by the user terminal UT. That is, the user terminal UT may not be able to acquire a complete moving image file from the web server WS. On the other hand, since the management server MS does not perform special playback of the moving image file, a complete moving image file can be acquired from the Web server WS. Therefore, the management server MS can input a complete moving image file to the overlay network ON. Furthermore, the management server MS can control the input amount of the moving image file according to the load status of the network NW and the node Nn when receiving the URL of the moving image file from the plurality of user terminals UT at the same time.

  As yet another example of the input control in step S21, the node processing unit 31c of the user terminal UT may be configured to always input a moving image file to a participating node. In this case, in step S21, the node processing unit 31c of the user terminal UT transmits the moving image file acquired in step S11 to the resident node. This resident node is the node Nn that has transmitted the content-less message in step S9. Then, the node processing unit 21b of the resident node acquires the IP addresses and port numbers of a predetermined number of nodes Nn to which the moving image file is input from the IP addresses and port numbers stored in the storage unit 22. For example, the IP address and port number of the node Nn that is the input destination of the moving image file are acquired from the IP address and port number registered in the routing table using DHT. As in the case of the user terminal UT, the IP address and port number of the node Nn that is the input destination of the moving image file may be acquired from the history information. Then, the node processing unit 21b of the resident node accesses the node Nn based on each acquired IP address and port number, and transmits a content storage request message. The subsequent operation is the same as when the node processing unit 31c of the user terminal UT transmits a content storage request message.

  In this way, the user terminal UT does not have to participate in the overlay network ON when the always participating node inputs the moving image file. For this reason, the node processing unit 31c of the user terminal UT does not have to perform the processes in steps S17 to S22. And the processing load of the user terminal UT can be reduced because a participating node always inputs a moving image file. In addition, when a constantly participating node inputs a moving image file, the possibility that the power is turned off during the input is lower than that of the user terminal UT. Therefore, the moving image file can be input to the overlay network ON more reliably than when the user terminal UT inputs.

  However, the resident node plays a role of transmitting main content in response to a request from the base terminal Tm-l connected to the base network NLm in the same base Pm. Further, the resident node is responsible for transmitting main content or sub-content in response to a request from another resident node. The processing load of the resident node that plays such a role needs to be reduced as much as possible. Therefore, it is desirable that the moving image file is input by the user terminal UT or the management server MS. When the user terminal UT or the management server MS inputs the moving image file, the overlay network ON can be stably operated.

  In the above embodiment, the user terminal UT has been described as an example of the second information processing apparatus of the present invention. However, the base terminal Tm-l may be the second information processing apparatus. In this case, the base terminal Tm-l includes the above-described web browser 31a, player 31b, and node processing unit 31c. Then, a moving image file can be uploaded to the Web server WS via the router Rm to the base terminal Tm-l. Furthermore, the base terminal Tm-l can perform the processes of steps S1 to S3, S8, S10, S12, S13, S16, S17, and S20 to S22 described above.

  In the above embodiment, the router Rm is described as an example of the first information processing apparatus of the present invention. However, the present invention is not limited to this, and the first information processing apparatus is a server connected to the network NW. Etc. Further, the first information processing apparatus may be basically a device such as a gateway that is regularly connected to the network NW.

  Moreover, in the said embodiment, although demonstrated taking the karaoke store as an example as a base, this base may be a school, a company, and other facilities besides this. For example, when the base is a school, an example of main content is data for teaching materials used at a base terminal installed in a classroom. Further, for example, when the base is a company, examples of main content include training data used at a base terminal installed in the room of the company.

  In the above embodiment, the peer-to-peer network using DHT is applied to the overlay network ON. However, the present invention is not limited to this. For example, a system using another overlay network may be applied. As a peer-to-peer system that does not use DHT, for example, there is a hybrid peer-to-peer system.

1,11,21,31 control unit 2,12,22,32 storage unit 3,13,23a, 23b, 39 communication unit 33 buffer memory WS Web server MS management server DS input server Nn node NW network ON overlay network S content Distribution system

Claims (11)

In a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses capable of communicating with each other via a network.
The information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus,
The content includes first content that is regularly distributed by the distribution system and second content that is different from the first content,
The second information processing apparatus
Obtaining means for obtaining the second content from a distribution device storing the second content;
Determination means for determining whether or not the second content acquired by the acquisition means satisfies an input condition for input to the overlay network;
If the determination means determines that the input condition is satisfied, a control means for executing control for inputting the second content to the overlay network as content that can be acquired by the overlay network;
A distribution system comprising: The distribution system includes an input server that inputs the first content into the overlay network,
The input server includes transmission means for transmitting the first content to the first information processing apparatus,
The first information processing apparatus includes a receiving unit that receives the first content transmitted from the input server;
Storage means for storing the received first content as content obtainable by the overlay network;
The distribution system according to claim 1, further comprising: The second information processing apparatus further includes search means for searching for the location of the second content in the overlay network,
3. The distribution system according to claim 1, wherein the acquisition unit acquires the second content from the distribution device when the second unit cannot be found by the search unit. The second information processing apparatus further includes second acquisition means for acquiring information indicating the popularity of the second content,
4. The determination unit according to claim 1, wherein when the popularity degree of the second content is equal to or higher than a predetermined popularity degree, the determination unit determines that the input condition is satisfied. 5. Distribution system. The distribution device includes:
Second receiving means for receiving the second content transmitted from an information processing apparatus participating in the overlay network or another information processing apparatus not participating in the overlay network;
Second storage means for storing the second content as content that can be distributed from the distribution device when the received second content satisfies a censorship standard for distribution from the distribution device;
The distribution system according to any one of claims 1 to 4, further comprising:   6. The information processing apparatus that stores the first content and the second content includes a deletion unit that deletes the second content in preference to the first content. The distribution system according to any one of the above. The distribution system includes a management server that manages the input of the content,
The second information processing apparatus
Receiving means for receiving, from a web browser, a request including location information extracted from a web page transmitted from a web server and indicating the location of the second content stored in the distribution device; Prepared,
The control means transmits location information included in the received request to the management server,
The management server
Third acquisition means for acquiring the second content from the distribution device based on the location information when the location information transmitted from the information processing device is received;
Input means for inputting the acquired second content to the overlay network;
The distribution system according to any one of claims 1 to 6, further comprising:   8. The content according to claim 1, wherein the second content is content that is input from or posted to an information processing device that participates in the overlay network or another information processing device that does not participate in the overlay network. The distribution system according to claim 1. The information processing apparatus included in a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses that can communicate with each other via a network. And
The information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus,
The content includes first content that is regularly distributed by the distribution system and second content that is different from the first content,
The second information processing apparatus
Obtaining means for obtaining the second content from a distribution device storing the second content;
Determination means for determining whether or not the second content acquired by the acquisition means satisfies an input condition for input to the overlay network;
If the determination means determines that the input condition is satisfied, a control means for executing control for inputting the second content to the overlay network as content that can be acquired by the overlay network;
An information processing apparatus comprising: In a distribution system configured such that an information processing apparatus acquires content from another information processing apparatus in an overlay network including a plurality of information processing apparatuses capable of communicating with each other via a network.
The information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus,
The content includes first content that is regularly distributed by the distribution system and second content that is different from the first content,
In the computer included in the second information processing apparatus,
Obtaining the second content from a distribution device storing the second content;
Determining whether the acquired second content satisfies an input condition for input to the overlay network;
If it is determined that the input condition is satisfied, executing a control for inputting the second content into the overlay network as content that can be acquired by the overlay network;
Information processing program to execute. A content input method in a distribution system configured such that an information processing device acquires content from another information processing device in an overlay network composed of a plurality of information processing devices capable of communicating with each other via a network,
The information processing apparatus includes a first information processing apparatus that regularly participates in the overlay network, and a second information processing apparatus that is different from the first information processing apparatus,
The content includes first content that is regularly distributed by the distribution system and second content that is different from the first content,
The content input method is:
Obtaining the second content from a distribution device storing the second content;
Determining whether the acquired second content satisfies an input condition for input to the overlay network;
If it is determined that the input condition is satisfied, executing a control for inputting the second content into the overlay network as content that can be acquired by the overlay network;
A content input method comprising:

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