JP4935734B2 - Content distributed storage system, node device, node processing program, and node processing method - Google Patents

Description

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

  In this type of peer-to-peer communication system, there is known a content distributed storage system in which content data is distributed and distributed (distributed storage) to a plurality of node devices. This improves fault tolerance and access dispersibility. It has been. The location of the content data distributed and stored in this way can be efficiently searched using a distributed hash table (hereinafter referred to as DHT (Distributed Hash Table)) as disclosed in Patent Document 1, for example.

  When a node device participating in the distributed content storage system desires to acquire desired content, the node device (root node) that manages the location of the content data is inquired using the DHT (query). ), The content data can be acquired and played back by connecting to another node device that stores the content data.

By the way, in the content distribution service, there are various methods for improving the utilization rate. One of them is to attract the user's interest by inserting additional information when reproducing content data. For example, additional information such as a review of a content viewer can be used as a judgment material when a user searches for content that suits his taste. In addition, by displaying additional information such as content viewers' comments during playback of content data, it is possible to give the content a new appeal, and it is also attractive to be able to freely add comments etc. to the content data. Can be. In the case of content distribution to which such additional information is added, a method of collecting additional information created by a content viewer on a server and reflecting them in content data from the server side can be considered.
JP 2006-197400 A

  However, in the above-described peer-to-peer content distributed storage system, it is one of the great advantages to reduce the number of servers as compared with the conventional client-server system. It is desirable to be able to realize a system that can efficiently use content together with content without installing a server.

The present invention has been made in consideration of the above points, etc., to have additional information on the content data, the efficiency the additional information along with the content may be available and the content distributed storage system, node device and node processing It is an object to provide a program and a node processing method .

In order to solve the above-described problem, according to the first aspect of the present invention, a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, and a plurality of locations of the plurality of content data are provided. The location of content data to be acquired from a plurality of node devices for managing the location of each content data in the distributed content storage system managed in a distributed manner by the node devices Content data that retrieves the content data from the retrieved other node device by retrieving the other node device that stores the content data by inquiring the root node device that is the node device that manages the content an acquiring unit, a reproduction control means for pre-Symbol to produce the acquired content data re During playback of the acquired content data, the additional information input means for inputting additional information for the content data in response to an input instruction from a user, the the obtained content data, and the input side information, Information stored in association with each other, and registration information for registering node information of the node device storing the content data as the node device storing the content data in the additional information storage unit. Registration information sending means for sending to the root node device managing the location of data, and when there is a request for the stored content data from another node device, the requested content data, Provide additional information for the requested content data to the other node device of the request source Comprising a pressurized information providing unit, and the additional information provided by the additional information providing means of another node device, the content data, and an additional information acquiring unit that acquires from the node device storing the content data, and The reproduction control means reproduces the acquired content data and the acquired additional information in synchronization .

According to the first aspect of the present invention, there is provided a distributed content storage system in which a plurality of content data are distributed and stored in a plurality of node devices, and the locations of the plurality of content data are distributed and managed by the plurality of node devices . Utilizing the advantage, the additional information added by the user can be distributed and stored in association with the content data, and the additional information can be efficiently used with the content data.
Further, it is possible to efficiently provide the additional information input in each node device to the other node device that requested the request together with the content data.

In order to solve the above-described problem, the invention according to claim 2 is configured such that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is present. The node device in the distributed content storage system that is distributed and managed by a plurality of node devices, wherein the content data to be acquired is selected from the plurality of node devices that manage the location of each content data. Content that searches for another node device that stores the content data by querying a root node device that is a node device that manages the location, and acquires the content data from the searched other node device Data acquisition means and reproduction control means for reproducing the acquired content data , During playback of the acquired content data, the additional information input means for inputting additional information for the content data in response to an input instruction from a user, a content storage means for storing the obtained content data, before If the serial acquired content data is stored as a node device that stores the stored content data, registration information and the inputted additional information for registering node information of the node device saved content data and a registration information sending means for sending to the root node device addressed that manages the location of stored content data, the additional information for the content data to be the acquisition target, the additional information acquisition for acquiring from said root node device And the reproduction control means is connected to the additional information acquisition means. And additional information acquired Ri, and the content data acquired by the content data acquisition means, characterized in that it reproduced in synchronization.

According to the second aspect of the present invention, there is provided a distributed content storage system in which a plurality of content data are distributed and stored in a plurality of node devices, and the locations of the plurality of content data are distributed and managed by the plurality of node devices. Utilizing the advantage, the additional information added by the user can be distributed and stored in association with the content data, and the additional information can be efficiently used with the content data.
Further, since the additional information is acquired from the root node device that manages the location of the content data corresponding to the additional information, the additional information can be distributed and stored in the entire system and efficiently shared.

In order to solve the above problem, the invention according to claim 3 is the node device that receives the registration information and the additional information transmitted from the node device according to claim 2 , wherein the node device receives the registration information. When there is an inquiry about the location of the content data to be acquired from the registration means for registering the node information of the node device that stores the content data and the additional information, and another node device based on the registered information. Comprises additional information transmitting means for transmitting node information of the node device storing the content data and additional information for the content data to the inquiring node device .

According to the third aspect of the present invention, the additional information can be distributed and stored in the entire system and efficiently shared.

In order to solve the above problems, the invention according to claim 4 is the above node device receives the registration information transmitted from the node device according to claim 1, based on the received registration information Te, the node information of the node device storing the content data registration means to register for each node device that stores the content data to be managed in location, from the node device storing the content data characterized in that it comprises an additional information transfer means for transferring the received additional information.

According to the invention of the fourth aspect , the additional information can be distributed and stored in the entire system and efficiently shared.

In order to solve the above problems, the invention according to claim 5, wherein a node device for receiving the additional information that has been transferred from the node device, the received additional information according to claim 4 If there is a request for the stored content data from another node device and the additional information storage means for storing the content data in association with the corresponding content data, the content data and the additional information corresponding thereto And additional information providing means for providing the information to the other node device .

According to the invention described in claim 5 , the additional information can be distributed and stored in the entire system and efficiently shared.

In order to solve the above-described problem, the invention of the node processing program according to claim 6 is characterized in that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, and the plurality of contents Acquired from a plurality of node devices that manage the location of each content data in a computer included in the node device in a distributed content storage system in which the location of data is managed by a plurality of node devices. By inquiring the root node device that is the node device that manages the location of the target content data, the other node device that stores the content data is searched, and the other node device that has been searched Acquiring content data; and acquiring the acquired content data A step of inputting additional information for the content data in response to an input instruction from a user during reproduction of the acquired content data, the acquired content data, and the input additional information And registering the node information of the node device that stores the content data as the node device that stores the content data in the additional information storage unit. Sending to the root node device managing the location of the stored content data, and when there is a request for the stored content data from another node device, the requested content data; , Additional information for the requested content data, and other nodes of the request source And a step of acquiring additional information and content data provided by another node device from a node device that stores the content data, and reproducing the acquired content data. In the step, the acquired content data and the acquired additional information are executed so as to be reproduced in synchronization with each other.

In order to solve the above-described problem, the invention of the node processing program according to claim 7, wherein a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the plurality of contents Acquired from a plurality of node devices that manage the location of each content data in a computer included in the node device in a distributed content storage system in which the location of data is managed by a plurality of node devices. By inquiring the root node device that is the node device that manages the location of the target content data, the other node device that stores the content data is searched, and the other node device that has been searched Acquiring content data; and acquiring the acquired content data A step of inputting additional information for the content data in response to an input instruction from a user during the reproduction of the acquired content data, and a step of storing the acquired content data in a content storage unit And when the acquired content data is stored, as the node device for storing the stored content data, the registration information for registering the node information of the node device storing the content data and the input Sending additional information to the root node device managing the location of stored content data; and acquiring additional information for the content data to be acquired from the root node device. Execute the content data again In the step of, it has been the additional information obtained from the root node apparatus, the content data acquired from the retrieved another node device, and is characterized in that to perform so as to reproduce in synchronism.

In order to solve the above-described problem, the invention of the node processing method according to claim 8 is that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, and the plurality of contents A node processing method executed in the node device in a distributed content storage system in which the location of data is managed by a plurality of node devices, the plurality of node devices managing the location for each content data The other node device that stores the content data is searched by inquiring of the root node device that is the node device that manages the location of the content data to be acquired from A content data acquisition step for acquiring the content data from the node device; A reproduction control step for reproducing the acquired content data; an additional information input step for inputting additional information for the content data in response to an input instruction from a user during the reproduction of the acquired content data; Content data and the input additional information associated with each other are stored in the additional information storage unit, and the content data is stored as a node device that stores the content data in the additional information storage unit A registration information sending step for sending registration information for registering the node information of the node device to the root node device managing the location of the saved content data, and the saved information from another node device; When requested for content data, the requested content data And additional information providing step for providing the additional information for the requested content data to the other node device of the request source, and the additional information and content data provided by the other node device. An additional information acquisition step acquired from the node device to be stored, wherein in the reproduction control step, the acquired content data and the acquired additional information are reproduced in synchronization with each other. .

In order to solve the above-described problem, the invention of the node processing method according to claim 9 is that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, and the plurality of contents A node processing method executed in the node device in a distributed content storage system in which the location of data is managed by a plurality of node devices, the plurality of node devices managing the location for each content data The other node device that stores the content data is searched by inquiring of the root node device that is the node device that manages the location of the content data to be acquired from A content data acquisition step for acquiring the content data from the node device; A reproduction control step for reproducing the acquired content data; an additional information input step for inputting additional information for the content data in response to an input instruction from a user during the reproduction of the acquired content data; A content storage step for storing the content data in the content storage means, and a node of the node device that stores the content data as a node device for storing the stored content data when the acquired content data is stored A registration information sending step for sending registration information for registering information and the inputted additional information to the root node device managing the location of the stored content data, and the content data to be acquired Additional information for the root no An additional information acquisition step acquired from the device, and in the reproduction control step, the additional information acquired in the additional information acquisition step and the content data acquired in the content data acquisition step are synchronized. And playing .

In order to solve the above problem, the content distributed storage system according to claim 10 is characterized in that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, A content distributed storage system in which the location of content data is distributed and managed by a plurality of node devices, wherein the node device is acquired from a plurality of node devices that manage the location of each content data By inquiring the root node device that is the node device that manages the location of the target content data, the other node device that stores the content data is searched, and the other node device that has been searched Content data acquisition means for acquiring content data, and the acquired content data Playback control means for playing back, additional information input means for inputting additional information for the content data in response to an input instruction from the user during playback of the acquired content data, the acquired content data, An additional information storage unit that stores the input additional information in association with each other, and a node device that stores content data in the additional information storage unit for registering node information of the node device that stores the content data When there is a request for the stored content data from registration information transmitting means for transmitting the registered information to the root node device managing the location of the stored content data and from another node device Requesting the requested content data and additional information for the requested content data An additional information providing unit provided to another node device, an additional information provided by the additional information providing unit of the other node device, and content data are acquired from the node device that stores the content data. An information acquisition unit, wherein the reproduction control unit reproduces the acquired content data and the acquired additional information in synchronization .

In order to solve the above problem, the content distributed storage system according to claim 11 is characterized in that a plurality of content data are distributed and stored in a plurality of node devices that can communicate with each other via a network, A content distributed storage system in which the location of content data is distributed and managed by a plurality of node devices, wherein the node device is acquired from a plurality of node devices that manage the location of each content data By inquiring the root node device that is the node device that manages the location of the target content data, the other node device that stores the content data is searched, and the other node device that has been searched Content data acquisition means for acquiring content data, and the acquired content data Reproduction control means for reproducing the content data, additional information input means for inputting additional information for the content data in accordance with an input instruction from the user during the reproduction of the acquired content data, and storing the acquired content data Content storage means for registering, and when the acquired content data is stored, as node device for storing the stored content data, registration information for registering node information of the node device storing the content data; Registration information sending means for sending the input additional information to the root node device that manages the location of stored content data; and additional information for the content data to be acquired, the root node device. Additional information acquisition means for acquiring from the reproduction control means , And the additional information acquisition unit additional information acquired by the content data acquired by the content data acquisition means, characterized in that it reproduced in synchronization.

According to the present invention, taking advantage of the content distributed storage system in which a plurality of content data is distributed and stored in a plurality of node devices, and the locations of the plurality of content data are distributed and managed by the plurality of node devices , The additional information added by the user can be provided in the content data, and the additional information can be efficiently used together with the content data.
Further, it is possible to efficiently provide the additional information input in each node device to the other node device that requested the request together with the content data.
Furthermore, the additional information can be distributed and stored in the entire system for efficient sharing.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the 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 distributed storage system.
[ 1. Configuration of distributed content storage system ]
First, with reference to FIG. 1 and the like, a schematic configuration and the like of the content distributed storage system according to the present embodiment will be described.

  FIG. 1 is a diagram illustrating an example of a connection mode of each node device in the distributed content storage system according to the present embodiment.

  As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4a, 4b, DSL (Digital Subscriber Line) line operators (devices) 5a, 5b, FTTH (Fiber To A network (real-world communication network) 8 such as the Internet is constructed by a line provider (device) 6 and a communication line (for example, a telephone line or an optical cable) 7. Note that a router for transferring data (packets) is appropriately inserted into the network 8 in the example of FIG.

  A plurality of node devices (hereinafter referred to as “nodes”) Nn (n = 1, 2, 3,...) Are connected to such a network 8 via a router. Each node Nn is assigned a unique manufacturing number and an IP (Internet Protocol) address. The content distributed storage system S according to the present embodiment is a peer-to-peer network system formed by participation of any of a plurality of nodes Nn, as shown in the upper frame 100 of FIG. It has become.

  A network 9 shown in the upper frame 100 of FIG. 1 is an overlay network 9 (logical network) that forms a virtual link formed using the existing network 8. Such an overlay network 9 is realized by a specific algorithm, for example, an algorithm using DHT.

  Each node Nn participating in the content distributed storage system S (in other words, the overlay network 9) is assigned a node ID, which is unique identification information having a predetermined number of digits. The node ID is, for example, a value (for example, the bit length is 160 bits) obtained by hashing an IP address or a manufacturing number individually assigned to each node Nn with a common hash function (for example, SHA-1). Yes, it will be distributed in one ID space without any bias.

  In addition, participation in the content distributed storage system S is performed by any node Nn (for example, the node N8) that has not participated in any node Nn (for example, a contact node that always participates in the system S) that has not participated. This is done by sending a participation message indicating a participation request. On the other hand, the content distributed storage system S leaves the content distributed storage system S when the power is turned off, for example.

  Each node Nn holds a routing table using DHT. This routing table defines the transfer destinations of various messages on the content distributed storage system S. Specifically, nodes Nn (that is, participating in the content distributed storage system S that are moderately separated in the ID space) A plurality of pieces of node information including node IDs, IP addresses, and port numbers of some other nodes Nn) are registered.

  One node Nn participating in the content distributed storage system S registers the minimum necessary node information of the nodes Nn among all the nodes Nn participating in the system S in the routing table, With respect to the node Nn that does not know (store) the node information, various messages are transferred between the nodes Nn to be delivered. Note that the routing table using DHT is generated when participating in the content distributed storage system S, for example.

  Such a routing table using DHT is well known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and will not be described in detail.

  By the way, in the content distributed storage system S, various content data having different contents (for example, data such as movies and music, and replicated replicas) are distributed and stored (stored) in a plurality of nodes Nn in a predetermined file format. The content data can be acquired and used by each node Nn by searching. For example, the content data of a movie with the title XXX is stored in the node N3, while the content data of the movie with the title YYY is stored in the node N8. , “Content holding nodes”). A plurality of different content data may be stored in one node Nn.

  Each of these content data is provided with information such as a content name (title) and a content ID (identification information unique to each content). This content ID is generated, for example, by hashing the content name + arbitrary numerical value (or may be the first few bytes of the content data) with a hash function common to obtaining the node ID (node ID and Placed in the same ID space). Alternatively, the system administrator may give a unique ID value (same bit length as the node ID) for each content. In this case, the content catalog information in which the correspondence between the content name and the content ID is written is distributed to all the nodes Nn.

  Further, the location of the content data thus distributed and stored, that is, the index information including the set of the node information of the node Nn storing the content data and the content ID corresponding to the content data is the content data. It is stored (stored in the index cache) and managed by a node Nn (hereinafter referred to as “root node” or “root node of content (content ID)”) as an example of a management device that manages the location of It has become. That is, the node information of the content holding node that stores the content data is managed by the root node so that it can be provided in response to an inquiry from another node Nn.

  For example, the index information for the content data of the movie with the title XXX is managed by the node N2 that is the root node of the content (content ID), and the index information for the content data of the movie with the title YYY is the content ( Managed by the node N7 which is the root node of the content ID). Further, such a root node is determined to be, for example, a node Nn having a node ID closest to the content ID (for example, the higher-order digits match more).

  When a user of a certain node Nn wants to acquire desired content data, the node Nn that desires to acquire the content data (hereinafter referred to as “user node”) manages the location of the content data to be acquired. The content holding node storing the content data is searched by inquiring to the root node, and the content data is obtained from the searched content holding node. Specifically, the user node generates a content location inquiry (search) message (query) including the content ID of the content selected by the user, its own IP address, etc., and routes it using its own DHT. Send to other nodes Nn according to the table. That is, the user node sends a content location inquiry (search) message (hereinafter simply referred to as “content search message”) to the root node (to the root node) (that is, the location of the content data to the root node). Inquiry).

  As a result, the content search message is transmitted between nodes Nn (referred to as relay nodes) participating in the content distributed storage system S until it reaches the root node that manages the location of the content data by DHT routing using the content ID as a key. It is transferred (relayed) and finally arrives at the root node.

  The attribute information such as the content name and content ID of the content to be selected by the user in each node Nn is described in, for example, content catalog information distributed from the content providing server to all the nodes Nn. The content ID included in the content search message may be generated by the user node by hashing the content name with the common hash function. The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that has received the content search message returns index information corresponding to the content ID included therein to the user node that is the transmission source of the content search message. As a result, the user node that has acquired the index information selects one of the content holding nodes indicated by the index information and makes a content request to the selected content holding node (transmits a content request message). From there, it becomes possible to acquire (download) and play back the content data.

  Alternatively, the root node that has received the content search message acquires index information corresponding to the content ID included in the content node from the index cache, selects one content holding node from the index information, and selects the selected content. The content search message is transmitted (transferred) to the holding node. As a result, the user node receives the notification from the content holding node and makes a content request to the content holding node, thereby acquiring and reproducing the content data from the content holding node.

  Then, the user node that has stored the content data provided from the content holding node informs (discloses) that the content data has been stored to the root node (in other words, the content holding node that stores the content data) As a registration node) to generate a publish (registration notification) message (an example of registration information) including the content ID of the content data and the self node information, and the publish message as the root node To (to the root node). As a result, the publish message arrives at the root node by DHT routing using the content ID as a key, like the content search message. Then, the root node registers (stores in the index cache area) index information including a set of node information and content ID included in the received publish message. Thus, the user node becomes a new content holding node that holds the content data. Note that the index information including the set of node information and content ID included in the publish message is also registered (cached) in the cache node in the transfer path to the root node.

Furthermore, in the content distributed storage system S, for example, there is content data to which additional information such as any user's comment (character data) or image data is added. Additional information on the content data is also stored (stored) in any of the nodes Nn, and each node Nn acquires the additional information and uses it together with the content data to which the additional information is added. It is possible. The additional information may be stored in the same node Nn together with the content data to which the additional information is added, but may be stored in a node Nn different from the node Nn in which the content data is stored. Details of storage and acquisition of such additional information will be described later.
[ 2. Configuration and function of node Nn ]
Next, the configuration and function of the node Nn will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a schematic configuration example of the node Nn.

  As shown in FIG. 2, each node Nn includes a control unit 11 as a computer composed of a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, and various data (for example, content data). , Index information, routing table using DHT, etc.) and a storage unit 12 composed of HD (hard disk) for storing and storing (storing) various programs, etc., and a buffer for temporarily storing received content data, etc. A memory 13, a decoder unit 14 for decoding (data expansion, decoding, etc.) encoded video data (video information) and audio data (audio information) included in the content data, and the decoded video data Video that is output as a video signal after being subjected to predetermined drawing processing A display unit 16 such as a CRT or a liquid crystal display for displaying video based on the video signal output from the video processing unit 15, and the decoded audio data into an analog audio signal D (Digital) / A ( Analog) After conversion, the audio processing unit 17 that amplifies and outputs the amplified signal, the speaker 18 that outputs the audio signal output from the audio processing unit 17 as a sound wave, and other nodes Nn and the like through the network 8 A communication unit 19 for performing communication control of information, and an input unit (for example, a keyboard, a mouse, a remote controller, or an operation panel) that receives an instruction from the user and gives an instruction signal corresponding to the instruction to the control unit 11 ) 20, and includes a control unit 11, a storage unit 12, a buffer memory 13, a decoder unit 14, and a communication unit 19. , And the input unit 20 are connected to each other via a bus 21. As the node Nn, a personal computer, an STB (Set Top Box), a TV receiver, or the like can be applied.

  In addition, the storage unit 12 stores an IP address, a port number, and the like of a contact node that is an access destination when participating in the distributed content storage system S.

  In such a configuration, the control unit 11 performs overall control by reading and executing a program (including the node processing program or the management processing program of the present invention) stored in the storage unit 12 or the like by the CPU, By participating in the distributed content storage system S, processing as at least one of the above-described user node, relay node, root node, cache node, and content holding node is performed. The node processing program and the management processing program may be downloaded from a predetermined server on the network 8, for example, or may be recorded on a recording medium such as a CD-ROM and a drive of the recording medium You may make it read via.

  Then, the control unit 11 that performs characteristic processing as a user node includes the content data acquisition unit, additional information acquisition unit, reproduction control unit, additional information input unit, content storage unit, additional information storage unit, and registration according to the present invention. It functions as information transmission means. In addition, the control unit 11 that performs characteristic processing as a root node functions as a registration unit, additional information transmission unit, additional information transfer unit, and the like in the present invention. In addition, the control unit 11 that performs characteristic processing as a content holding node functions as additional information storage means, additional information provision means, and the like in the present invention.

  Specifically, as described above, the control unit 11 of the user node makes an inquiry to the root node that manages the location of the content data to be acquired, so that the content holding node that stores the content data is selected. A search is performed, and content data is acquired from the searched content holding node via the network 8 and the communication unit 19. The content data acquired in this way is temporarily stored in the buffer memory 13 and then read out and stored in the storage unit 12. When the content data is stored, as described above, the control unit 11 of the user node generates a publish message including the content ID of the content data and its own node information, and directs this to the root node. To send (to the root node).

  The acquired content data may be read and reproduced (streaming reproduction) while being accumulated in the buffer memory 13, or may be read while being accumulated in the buffer memory 13 and stored in the storage unit 12. After the storage, it may be configured to be read out from the storage unit 12 and played back when the user gives a playback instruction.

  Furthermore, when additional information such as a comment is added to the content data to be acquired, the control unit 11 of the user node stores the content data as additional information for the content data to be acquired. A process of acquiring from the content holding node or the root node managing the location of the content data via the network 8 and the communication unit 19 is performed.

  Here, when additional information is acquired from the content holding node, the additional information is acquired from the content holding node together with the content data. On the other hand, when additional information is acquired from the root node, the additional information is acquired from the root node by an inquiry about the location of the content data to the root node.

  Then, the control unit 11 of the user node performs reproduction control for reproducing the acquired content data and the acquired additional information in synchronization. By such playback control, for example, content data and additional information stored in the buffer memory 13 or stored in the storage unit 12 are read out, and the decoder unit 14, the video processing unit 15, the display unit 16, and the audio processing unit 17 are read out. And reproduced through the speaker 18. Thereby, for example, when a video related to the content data is displayed on the display unit 16, additional information such as a comment is displayed superimposed on the video, and the content viewer can view the content data. A comment or the like added by another user can be seen together with the video.

  Meanwhile, the control unit 11 of the user node receives an input unit from the user while the content data transmitted from the content holding node is received and read and reproduced while being stored in, for example, the buffer memory 13 (during reproduction). When there is an instruction to input additional information via 20, the additional information for the content data is input and temporarily stored. Such additional information includes information indicating the input timing, for example, information indicating when the additional information is input from the start of reproduction of the content data.

  For example, when the reproduction of the content data is completed and the storage of the content data in the storage unit 12 is also completed, the control unit 11 of the user node includes the additional information in the publish message, and this is included in the content To send to the root node (to the root node).

  In addition, after the acquired content data is stored in the storage unit 12 and the publish message is transmitted toward the root node, the content data is read from the storage unit 12 and is being played back. Additional information input processing for the content data can be performed (that is, performed by the control unit 11 of the content holding node). In this case, a publish message including the additional information is regenerated and sent to the content root node (to the root node).

  Then, based on the transmitted and received publish message, the root node control unit 11 registers index information including a set of node information and content ID included in the publish message, and further, the location information by the root node is registered. A process of transferring the received additional information to each content holding node storing content data to be managed is performed. In this case, the control unit 11 of the content holding node stores the additional information received from the root node in association with the content data corresponding thereto, and when the content data is requested from the user node. That is, when a content request message is received, the content data and additional information corresponding to the content data are provided to the user node. With this configuration, additional information is shared, and the user of each node Nn can refer to the additional information added by other users.

  As another example, the control unit 11 of the root node registers index information including a set of node information and content ID included in the publish message based on the transmitted and received publish message, and further includes the index information. It may be configured to perform processing for registering additional information in association with each other. In this case, when there is an inquiry about the location of the content data to be acquired from the user node, that is, when the content search message is received, the control unit 11 of the root node stores the content data for storing the content data. The index information including the node information of the node and the additional information for the content data are transmitted to the inquiring user node. Also with this configuration, additional information can be shared, and the user of each node Nn can refer to the additional information added by other users.

As yet another example, the control unit 11 of the user node stores the input additional information in association with the content data to which the additional information is added, and directs a publish message that does not include the additional information to the root node. A process of sending (to the root node) may be performed. In this case, the additional information cannot be shared, but the node information included in the publish message sent from the user node is registered as index information, so that the user node becomes a content holding node. When there is a request for content data from another user node, the control unit 11 of the content holding node provides the content data and additional information stored in association with the content data to the user node. Processing can be performed.
[ 3. Content Distributed Storage System Operation ]
Next, the operation of the distributed content storage system S will be described separately in the first to third embodiments. Example 1
First, the operation of the distributed content storage system S according to the first embodiment will be described with reference to FIGS.

  FIG. 3 is a flowchart illustrating an example of the main process in the control unit 11 of the node Nn according to the first embodiment. FIG. 4 is a flowchart illustrating details of the content reproduction process in step S3 of FIG. FIG. 5 is a conceptual diagram showing the flow of messages and the like in the first embodiment.

  3 is started when power is turned on at a certain node Nn, participation processing (participation message transmission to a contact node) is executed, and participation in the content distribution storage system S is performed.

  First, in step S1, the control unit 11 determines whether or not there is a power-off (shutdown) command. If there is no power-off command (step S1: NO), the control unit 11 proceeds to step S2 and proceeds to a power-off command. If there is (step S1: YES), the process ends.

  In step S2, the control unit 11 determines whether or not there is a content request instruction from the user via the input unit 20, and if there is the content request instruction (step S2: YES), step S3 If there is no content request instruction (step S2: NO), the process proceeds to step S4.

  In the content reproduction process of step S3, as shown in FIG. 4, the control unit 11 sends a content search message including the content ID of the content (selected by the user) and its node information related to the content request instruction to the content. Transmitting to the root node (to the root node) (step S31). Thereby, the said control part 11 receives and acquires the index information returned from the said route node (step S32).

  Next, the control unit 11 selects one from the content holding nodes indicated by the index information, and transmits a content request message to the selected content holding node (step S33). Thereby, the control unit 11 receives and acquires the content data transmitted from the content holding node and the additional information for the content data (step S34). In this example, it is assumed that additional information is added to the content data. When additional information is not added, only content data is acquired.

  Next, the control unit 11 starts reproduction by synchronizing the content data and the additional information (step S35). For example, the control unit 11 is synchronized so that the additional information is reproduced and output in accordance with information indicating the input timing included in the additional information.

  Next, when the content data is being reproduced (step S36: YES), the control unit 11 performs input check (input confirmation) of additional information such as a comment from the user via the input unit 20 (step S37). ) When the additional information is input (step S38: YES), the input additional information includes information indicating the input timing (for example, elapsed time from the start of reproduction), and the additional information is temporarily stored. Then, it is stored in a RAM or the like (step S39). On the other hand, if additional information has not been input (step S38: NO), the process returns to step S36 and the same processing is continued.

  When the reproduction of the content data is finished, that is, when the content data is not being reproduced (step S36: NO), the control unit 11 determines whether or not the content data is stored and saved in the storage unit 12. (Step S40) When it is stored (Step S40: YES), the process proceeds to Step S41. Note that the storage of the content data in the storage unit 11 may be performed during the reproduction of the content data, or may be performed after the reproduction ends. Further, the additional information temporarily stored in association with the stored content data is also stored.

  In step S41, the control unit 11 generates a publish message including the content ID of the content data, the node information of the own node, and the additional information that is input and stored, and the publish message is transmitted to the root node. To (to the root node). For example, in the example of FIG. 5A, the additional information 1 input at the node N1 that is the user node is included in the publish message, and the message is transferred toward the root node of the content data X. Yes.

  Returning to FIG. 3, in step S <b> 4, the control unit 11 determines whether or not a publish message has been received. If the message is received (step S <b> 4: YES), the process proceeds to step S <b> 5 and receives the message. If not (step S4: NO), the process proceeds to step S9. In step S5, the control unit 11 determines whether or not the own node is the root node of the content ID included in the publish message, that is, whether or not the node Nn having the node ID closest to the content ID is the own node. Determine from the routing table. If the own node is not the root node (step S5: NO), the control unit 11 identifies the node Nn closest to the content ID included in the message from its own routing table, and determines the identified node Nn. On the other hand, the publish message is transferred (step S6).

  On the other hand, when the own node is the root node (step S5: YES), the control unit 11 registers (stores in the index cache area) index information including a set of node information and content ID included in the publish message. (Step S7).

  Next, the control unit 11 acquires additional information from the publish message, specifies a content holding node storing content data corresponding to the content ID included in the publish message from the index information, and stores the specified content holding An additional information storage request message including the content ID of the content data and the acquired additional information is transmitted to the node (step S8). That is, the root node transfers the additional information included in the received publish message to the content holding node. For example, in the example of FIG. 5A, a publish message sent from the node N1 that is the user node is received by the node N2 that is the root node of the content data X, and the content holding that stores the content data X A state in which an additional information storage request message including additional information 1 is transmitted to the nodes N3 to N5 is shown.

  Next, in step S9, the control unit 11 determines whether or not an additional information storage request message has been received, and when the message is received (step S9: YES), the control unit 11 proceeds to step S10 and transmits the message. If not received (step S9: NO), the process proceeds to step S11. In step S10, the control unit 11 receives the additional information included in the received additional information storage request message, and stores and stores it in the storage unit 12 in association with the content data corresponding to the content ID included in the message. For example, the example of FIG. 5B shows a state in which the additional information 1 is stored in association with the content data X in the content holding nodes N3 to N5 storing the content data X. In this way, each time the content holding node receives new additional information, it stores it in association with the corresponding content data. In this way, all additional information added to a certain content by many users is accumulated in each content holding node via the root node. As a result, the additional information can be more efficiently stored in all the content holding nodes of the content data X. Further, it is possible to efficiently provide the additional information together with the content data at the time of content request from the user node.

  Next, in step S11, the control unit 11 determines whether or not a content search message has been received. If the message has been received (step S11: YES), the control unit 11 proceeds to step S12 and receives the message. If not (step S11: NO), the process proceeds to step S15. In step S12, the control unit 11 determines whether or not the own node is the root node of the content ID included in the content search message, that is, whether or not the node Nn having the node ID closest to the content ID is the own node. Determine from its own routing table. If the own node is not the root node (step S12: NO), the control unit 11 specifies the node Nn closest to the content ID included in the message from its own routing table, and determines the specified node Nn. On the other hand, the content search message is transferred (step S13).

  On the other hand, when the own node is the root node (step S12: YES), the control unit 11 sends the index information corresponding to the content ID included in the content search message to the user node that is the transmission source of the content search message. A reply is made (step S14). In the example of FIG. 5B, the content search message sent from the node N6 that is the user node is received by the node N2 that is the root node of the content data X, and the index information is returned to the node N6. It shows a state.

  Next, in step S15, the control unit 11 determines whether or not a content request message has been received. If the message is received (step S15: YES), the control unit 11 proceeds to step S16 and receives the message. If not (step S15: NO), the process proceeds to step S17. In step S16, the control unit 11 reads the content data requested by the content request message and the additional information stored in association with the content data from the storage unit 12, and retrieves the content data and the additional information from the requesting user node. Send to. In this example, it is assumed that additional information is added to the content data. If no additional information is added, only content data is transmitted. In the example of FIG. 5B, the node N4 that is the content holding node transmits the content data X and the additional information 1 corresponding thereto in response to the content request from the node N6 that is the user node.

  In other processing in step S17, other message reception processing and the like are performed.

(Example 2)
Next, the operation of the content distribution storage system S according to the second embodiment will be described with reference to FIGS.

  FIG. 6 is a flowchart illustrating an example of main processing in the control unit 11 of the node Nn according to the second embodiment, and FIG. 7 is a flowchart illustrating details of the content reproduction processing in step S23 of FIG. FIG. 8 is a conceptual diagram showing the flow of messages and the like in the second embodiment. In FIGS. 6 and 7, the same description as in FIGS. 3 and 4 will not be repeated.

  In the content reproduction process of step S3 performed when there is a content request instruction in step S22 of FIG. 6 (step S22: YES), as shown in FIG. 7, the control unit 11 is the same as step S31 of FIG. The content search message is sent to the root node of the content (step S231). In this case, the control unit 11 acquires additional information together with index information from the root node (step S232).

  Next, as in step S33 of FIG. 4, the control unit 11 transmits a content request message to the content holding node (step S233). In this case, the content data is acquired from the content holding node (step S234). Additional information is not acquired.

  Note that the processes in steps S235 to S241 in FIG. 6 are the same as the processes in steps S35 to S41 in FIG.

  Returning to FIG. 6, the processing in steps S24 to S26 is the same as the processing in steps 4 to S6 in FIG. 4, but the control unit 11 associates the index information and the additional information included in the received publish message. Registration is performed (step S27), and the additional information storage request message is not transmitted to the content holding node (FIG. 8A). Thus, every time new additional information is received, the root node is registered in association with the corresponding index information. In this way, all additional information added to a certain content by many users is accumulated in the root node. As a result, the root node can centrally manage each additional information input in a plurality of user nodes. Further, additional information can be efficiently provided together with index information when inquiring about the location of content data from a user node.

  Next, the processing in steps S28 to S30 is the same as the processing in steps 11 to S13 in FIG. 4, but the control unit 11 is associated with the index information corresponding to the content ID included in the content search message. The additional information stored is acquired, and the index information and the additional information are returned to the user node that is the transmission source of the content search message (step S31). In the example of FIG. 8B, the content search message sent from the node N6 that is the user node is received by the node N2 that is the root node of the content data X, and the index information and additional information 1 are sent to the node N6. Shows a reply.

  If the content request message is received in step S32 (step S32: YES), the control unit 11 transmits the content data requested by the content request message to the requesting user node (step S33). The additional information is not transmitted (FIG. 8B).

(Example 3)
Next, the operation of the content distribution storage system S according to the third embodiment will be described with reference to FIGS. 9 to 11.

  FIG. 9 is a flowchart illustrating an example of main processing in the control unit 11 of the node Nn according to the third embodiment. FIG. 10 is a flowchart illustrating details of the content reproduction processing in step S43 in FIG. FIG. 11 is a conceptual diagram illustrating the flow of messages and the like in the third embodiment. In FIGS. 9 and 10, the same description as in FIGS. 3 and 4 or FIGS. 6 and 7 is omitted.

  In the content reproduction process of step S43 performed when there is a content request instruction in step S42 of FIG. 9 (step S42: YES), as shown in FIG. 10, the control unit 11 is the same as step S231 of FIG. The content search message is sent to the root node of the content (step S431). In this case, the control unit 11 acquires index information from the root node (step S432) and does not acquire additional information.

  Next, the control unit 11 transmits a content request message to the content holding node (step S433). When the content holding node stores additional information for the content data related to the request, the content data and the additional information are acquired (step S434).

  Note that the processing in steps S435 to S440 in FIG. 10 is the same as the processing in steps S35 to S40 in FIG.

  In step S441, unlike step S41 in FIG. 7, the publish message sent to the root node does not include additional information (FIG. 11A).

  Returning to FIG. 9, the processing in steps S44 to S47 is the same as the processing in steps 4 to S7 in FIG. 4, but the additional information is not included in the received publish message. There is no transfer to the holding node.

  Moreover, the process of step S48-S51 is the same as the process of step 11-S14 of FIG.

  When the content request message is received in step S52 (step S52: YES), the control unit 11 determines that the additional information is stored in association with the content data requested by the content request message. The information is read from the storage unit 12, and the content data and additional information are transmitted to the requesting user node (step S53). In the example of FIG. 11B, the node N1 that is the content holding node transmits the content data X and the additional information 1 corresponding thereto in response to the content request from the node N7 that is the user node. . As described above, in the third embodiment, the additional information input in each node Nn is stored together with the content data, but is not transmitted by the publish message. Therefore, the content holding node has different additional information. However, additional information stored in response to content requests from other user nodes is provided together with content data. For example, in FIG. 11B, when the additional information 7 is input from the node N7 that has acquired the additional information 1 together with the content data from the node N1, the additional information 7 is stored in association with the content data and the additional information 1. Thereafter, when the content data is provided in response to a content request from another user node, the additional information 1 and the additional information 7 are also provided together.

  As described above, according to the above-described embodiment, the additional data added by the user is provided in the content data by using the advantage of the peer-to-peer content distributed storage system S without using the server, and the addition is performed. Information can be used efficiently together with content data. In particular, according to the configurations of the first and second embodiments, since the input additional information is incorporated into a publish message and sent to the root node, the additional information can be shared more efficiently. Further, since the additional information can be acquired together with the index information or the content data when inquiring about the location of the content data to the root node or when requesting the content to the content holding node, the load applied to the system S is suppressed, Additional information can be used by all nodes Nn participating in the system S.

  Moreover, although the content distributed storage system S in the said embodiment was demonstrated on the assumption that it was formed by the algorithm using DHT, this invention is not limited to this.

It is a figure which shows an example of the connection aspect of each node apparatus in the content distributed storage system which concerns on this embodiment. It is a figure which shows the example of an outline structure of the node Nn. 6 is a flowchart illustrating an example of main processing in a control unit 11 of a node Nn according to the first exemplary embodiment. It is a flowchart which shows the detail of the content reproduction process in step S3 of FIG. FIG. 3 is a conceptual diagram illustrating a flow of messages and the like in the first embodiment. 10 is a flowchart illustrating an example of main processing in a control unit 11 of a node Nn according to the second embodiment. It is a flowchart which shows the detail of the content reproduction process in FIG.6 S23. It is a conceptual diagram which shows the flow of the message etc. in Example 2. FIG. 14 is a flowchart illustrating an example of main processing in a control unit 11 of a node Nn according to the third embodiment. It is a flowchart which shows the detail of the content reproduction process in FIG.9 S43. It is a conceptual diagram which shows the flow of the message etc. in Example 3. FIG.

Explanation of symbols

8 Network 9 Overlay Network 11 Control Unit 12 Storage Unit 13 Buffer Memory 14 Decoder Unit 15 Video Processing Unit 16 Display Unit 17 Audio Processing Unit 18 Speaker 19 Communication Unit 20 Input Unit 21 Bus Nn Node S Content Distributed Storage System

Claims (11)

A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices The node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data . Content data acquisition means for searching for another node device and acquiring the content data from the searched other node device ;
A reproduction control means for re-produce the previous SL obtained content data,
Additional information input means for inputting additional information for the content data in response to an input instruction from the user during reproduction of the acquired content data;
Additional information storage means for storing the acquired content data and the input additional information in association with each other;
The root node device that manages the location of the stored content data and registration information for registering the node information of the node device that stores the content data as the node device that stores the content data in the additional information storage means Registration information sending means to send to,
When there is a request for the stored content data from another node device, the requested content data and additional information for the requested content data are provided to the other node device of the request source. Additional information providing means;
Additional information acquisition means for acquiring additional information provided by the additional information providing means of another node device and content data from a node device that stores the content data;
With
The playback control means plays back the acquired content data and the acquired additional information in synchronization with each other. A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices The node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. Content data acquisition means for searching for another node device and acquiring the content data from the searched other node device;
Playback control means for playing back the acquired content data;
Additional information input means for inputting additional information for the content data in response to an input instruction from the user during reproduction of the acquired content data;
Content storage means for storing the acquired content data ;
If the previous SL acquired content data is stored as a node device that stores the stored content data, registered information and the input for registering node information of the node device saved content data added information, and registration information sending means for sending to the root node device addressed that manages the location of stored content data,
Additional information acquisition means for acquiring additional information for the content data to be acquired from the root node device;
With
The node device characterized in that the reproduction control means reproduces the additional information acquired by the additional information acquisition means and the content data acquired by the content data acquisition means in a synchronized manner . The node device that receives the registration information and the additional information transmitted from the node device according to claim 2 ,
Registration means for registering node information of the node device that stores the content data and the additional information based on the received registration information;
When there is an inquiry about the location of the content data to be acquired from another node device, the node information of the node device storing the content data and the additional information for the content data are transmitted to the inquiring node device Additional information transmitting means to
A node device comprising: A said node device that receives the registration information transmitted from the node device according to claim 1,
Based on the received registration information, and registration means the node information of the node device to register for storing the content data,
Additional information transfer means for transferring the additional information received from the node device storing the content data to each node device storing the content data to be managed ;
A node device comprising: A node device for receiving the additional information that has been transferred from the node device according to claim 4,
Additional information storage means for storing the received additional information in association with content data corresponding thereto ;
When there is a request for the stored content data from another node device, additional information providing means for providing the content data and additional information for the content data to the other node device ;
A node device comprising: A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices In the computer included in the node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. Searching for another node device and obtaining the content data from the other node device searched;
Replaying the acquired content data;
Inputting additional information for the content data in response to an input instruction from a user during reproduction of the acquired content data;
Storing the acquired content data and the input additional information in association with each other in an additional information storage unit;
The root node device that manages the location of the stored content data and registration information for registering the node information of the node device that stores the content data as the node device that stores the content data in the additional information storage means Sending to the address,
When there is a request for the stored content data from another node device, the requested content data and additional information for the requested content data are provided to the other node device of the request source. Steps,
Acquiring additional information and content data provided by another node device from the node device storing the content data;
And execute
In the step of reproducing the acquired content data, the node processing program is executed so as to reproduce the acquired content data and the acquired additional information in synchronization . A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices In the computer included in the node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. Searching for another node device and obtaining the content data from the other node device searched;
Replaying the acquired content data;
Inputting additional information for the content data in response to an input instruction from a user during reproduction of the acquired content data;
Storing the acquired content data in a content storage means;
When the acquired content data is stored, registration information for registering node information of the node device storing the content data as the node device storing the stored content data and the input additional information Sending to the root node device that manages the location of the stored content data;
Acquiring additional information for the content data to be acquired from the root node device;
And execute
In the step of reproducing the acquired content data, the additional information acquired from the root node device and the content data acquired from the searched other node device are executed in a synchronized manner. A node processing program characterized by causing A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices A node processing method executed in the node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. A content data acquisition step of searching for another node device and acquiring the content data from the searched other node device;
A reproduction control step of reproducing the acquired content data;
An additional information input step of inputting additional information for the content data in response to an input instruction from the user during the reproduction of the acquired content data;
An additional information storage step of storing the acquired content data and the input additional information in association with each other in an additional information storage unit;
The root node device that manages the location of the stored content data and registration information for registering the node information of the node device that stores the content data as the node device that stores the content data in the additional information storage means Registration information sending step to send to,
When there is a request for the stored content data from another node device, the requested content data and additional information for the requested content data are provided to the other node device of the request source. An additional information providing step;
An additional information acquisition step of acquiring additional information and content data provided by another node device from the node device storing the content data;
Including
The reproduction in the control step, the node processing method, wherein the content data to which the acquired, and the acquired additional information, to play to synchronize the. A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices A node processing method executed in the node device in
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. A content data acquisition step of searching for another node device and acquiring the content data from the searched other node device;
A reproduction control step of reproducing the acquired content data;
An additional information input step of inputting additional information for the content data in response to an input instruction from the user during the reproduction of the acquired content data;
A content storage step of storing the acquired content data in a content storage means;
When the acquired content data is stored, registration information for registering node information of the node device storing the content data as the node device storing the stored content data and the input additional information Sending registration information to the root node device that manages the location of the stored content data;
An additional information acquisition step of acquiring additional information for the content data to be acquired from the root node device;
Including
Wherein the reproduction control step, the acquired additional information in the additional information acquiring step, and a content data acquired in the content data acquisition step, node processing method characterized in that play in synchronization. A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices Because
The node device is
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. Content data acquisition means for searching for another node device and acquiring the content data from the searched other node device;
Playback control means for playing back the acquired content data;
Additional information input means for inputting additional information for the content data in response to an input instruction from the user during reproduction of the acquired content data;
Additional information storage means for storing the acquired content data and the input additional information in association with each other;
The root node device that manages the location of the stored content data and registration information for registering the node information of the node device that stores the content data as the node device that stores the content data in the additional information storage means Registration information sending means to send to,
When there is a request for the stored content data from another node device, the requested content data and additional information for the requested content data are provided to the other node device of the request source. Additional information providing means;
Additional information acquisition means for acquiring additional information provided by the additional information providing means of another node device and content data from a node device that stores the content data;
With
The content distribution storage system , wherein the reproduction control means reproduces the acquired content data and the acquired additional information in synchronization . A distributed content storage system in which a plurality of content data is distributed and stored in a plurality of node devices that can communicate with each other via a network, and the location of the plurality of content data is distributed and managed by the plurality of node devices Because
The node device is
The content data is stored by inquiring of the root node device that manages the location of the content data to be acquired from among the plurality of node devices that manage the location of each content data. Content data acquisition means for searching for another node device and acquiring the content data from the searched other node device;
Playback control means for playing back the acquired content data;
Additional information input means for inputting additional information for the content data in response to an input instruction from the user during reproduction of the acquired content data;
Content storage means for storing the acquired content data;
When the acquired content data is stored, registration information for registering node information of the node device storing the content data as the node device storing the stored content data and the input additional information Registration information sending means for sending the stored content data to the root node device managing the location of the stored content data;
Additional information acquisition means for acquiring additional information for the content data to be acquired from the root node device;
With
The content distribution storage system , wherein the reproduction control means reproduces the additional information acquired by the additional information acquisition means and the content data acquired by the content data acquisition means in a synchronized manner .

Images