JP2011204091A - Information processing apparatus, information processing program, marker information management method and delivery system - Google Patents

Abstract

An information processing apparatus, an information processing program, a landmark information management method, and a distribution system capable of reducing the burden on a node apparatus that manages list information even if the number of registered comment information and the like in the list information increases. I will provide a.
An information processing apparatus stores list information for registering one or more mark management information including mark information indicating a mark given in content data and position information indicating an output position of the mark information. Then, when the data amount of the stored list information is equal to or greater than the predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than the predetermined number, at least one of the list information is stored. The mark management information of each section is stored in another information processing apparatus as content data that can be acquired via the overlay network.
[Selection] Figure 5

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. The peer-to-peer distribution system is a system in which a plurality of content data is distributed and stored in a plurality of node devices, and the content data can be shared among the node devices. Hereinafter, the content data is referred to as “content”. In the peer-to-peer type distribution system, it is possible to reduce the load concentration on the server as in the client-server type distribution system. In addition, the location of the content distributed and stored in the peer-to-peer distribution system can be efficiently searched using a distributed hash table as disclosed in Patent Document 1, for example.

JP 2006-197400 A

  By the way, in a peer-to-peer distribution system, content acquired from another node device is reproduced and output by a user operation. There is a demand for a user who views the content being reproduced and output to write, for example, comment information at a desired reproduction position of the content and share it with other users. In this case, the user gives comment information or the like to the desired reproduction position of the content. Then, it is conceivable that each comment information or the like given by a plurality of users is registered in the list information and managed by a predetermined node device.

  However, when the number of registered comment information and the like in the list information increases, there is a problem that the burden on the node device that manages the list information increases.

  Therefore, the present invention has been made in view of the above problems and the like, and it is possible to reduce the burden on the node device that manages the list information even if the number of registrations of comment information to the list information increases. An object is to provide an information processing apparatus, an information processing program, a landmark information management method, a distribution system, and the like.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network. Each information processing apparatus is an information processing apparatus in a distribution system configured to acquire the content data from another information processing apparatus via the overlay network, and a mark given to the content data Storage means for storing list information for registering one or more mark management information including mark information indicating the position information indicating the output position of the mark information, and the list in response to a request from another information processing apparatus Transmitting means for transmitting information to the other information processing apparatus, and data of the list information stored in the storage means Determination means for determining whether or not the number of the landmark management information in the list information is equal to or greater than a predetermined number, and the data amount of the list information by the determination means is equal to or greater than a predetermined data amount, Alternatively, if it is determined that the number of the landmark management information in the list information has reached a predetermined number or more, the content that can acquire at least a part of the landmark management information in the list information via the overlay network And generating means for generating a message to be stored as data in another information processing apparatus.

  According to a second aspect of the present invention, in the information processing apparatus according to the first aspect, from the list information, a part of the mark management information in the list information is left in the list information, and the part of the information The information processing apparatus further includes a determination unit that determines the other mark management information except for the mark management information, and the generation unit includes other pieces of content management data determined by the determination unit as content data that can be acquired via the overlay network. A message for storing in an information processing apparatus is generated.

  According to a third aspect of the present invention, in the information processing apparatus according to the second aspect, the landmark management information includes date information indicating a date when the landmark management information is registered in the list information, The determining means refers to the date information included in the landmark management information, and determines the landmark management information registered before the date retroactive for a predetermined period from the current date from the list information.

  According to a fourth aspect of the present invention, in the information processing apparatus according to the second aspect, the mark management information includes identification information for identifying a user who has instructed the provision of the mark information or attribute information indicating a user attribute. An acquisition means for acquiring identification information for identifying a user or attribute information indicating a user attribute as condition information for determining the landmark management information from the list information; The landmark management information including the identification information or the attribute information acquired as the condition information is determined from the list information.

  According to a fifth aspect of the present invention, in the information processing device according to the second aspect, as the condition information for determining the landmark management information from the list information, a time from the output start position to the end position of the content is calculated. Position information indicating an output position of the mark information included in the mark management information is further provided with an acquisition unit that acquires section information indicating one or more sections among sections divided at a predetermined time interval. The mark management information including the mark information given in the section indicated by the section information acquired as the condition information is determined from the list information.

  According to a sixth aspect of the present invention, in the information processing apparatus according to any one of the first to fifth aspects, the landmark information is comment information input from an input unit of the information processing apparatus by the user. It is characterized by that.

  According to a seventh aspect of the present invention, in the information processing apparatus according to any one of the first to sixth aspects, the storage means stores content data to which the landmark information included in the landmark management information is added. Location information indicating a location is stored, and the transmission unit transmits the location information to the information processing device when transmitting the list information to the information processing device in response to the request. .

  The invention according to claim 8 is the information processing apparatus according to any one of claims 1 to 7, wherein the mark management information stored in the other information processing apparatus as the content data includes the overlay. In the network, unique identification information for identifying the content data is given by a predetermined device connected to the network, and the storage means stores the content information from the list information to the other information processing device. The identification information given to the stored landmark management information is stored, and the transmission means transmits the identification information to the information processing apparatus when transmitting the list information to the information processing apparatus in response to the request. It transmits to an apparatus, It is characterized by the above-mentioned.

  According to the ninth aspect of the present invention, content data is stored in one or more information processing devices in an overlay network including a plurality of information processing devices that can communicate with each other via a network. Mark information indicating a mark given in the content data to a computer included in the information processing apparatus in the distribution system configured to acquire the content data from another information processing apparatus via the overlay network; and Storing list information for registering one or more pieces of mark management information including position information indicating an output position of the mark information, and in response to a request from another information processing apparatus, the list information is changed to the other information. Transmitting to the processing device; and the amount of data of the stored list information is greater than or equal to a predetermined amount of data Or determining whether or not the number of the landmark management information in the list information has reached a predetermined number or more, and the data amount of the list information is greater than or equal to a predetermined data amount, or the landmark management information in the list information When it is determined that the number is equal to or greater than a predetermined number, at least a part of the landmark management information in the list information is stored in another information processing apparatus as content data that can be acquired via the overlay network And a step of generating the message.

  According to the tenth aspect of the present invention, content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network. A mark information management method in a distribution system configured to acquire content data from another information processing apparatus via the overlay network, wherein the information processing apparatus displays a mark given in the content data. Storing list information for registering one or more mark management information including mark information to be displayed and position information indicating an output position of the mark information, and the information processing apparatus responding to a request from another information processing apparatus Transmitting the list information to the other information processing device, and the information processing device stores the stored information. Determining whether the data amount of the list information is equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than a predetermined number; Is determined to be equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than a predetermined number, the at least part of the landmark management information in the list information is Generating a message to be stored in another information processing apparatus as content data that can be acquired via the overlay network.

  According to an eleventh aspect of the present invention, content data is stored in one or more information processing devices in an overlay network including a plurality of information processing devices that can communicate with each other via a network. In the distribution system configured to acquire the content data from another information processing apparatus via the overlay network, the information providing apparatus includes mark information indicating a mark given in the content data and the mark information Storage means for storing one or more pieces of mark management information including position information indicating the output position of the information, and the list information in response to a request from another information processing apparatus. The data amount of the list information stored in the storage means and the transmission means to be transmitted to the apparatus is greater than or equal to a predetermined data amount. Determining means for determining whether or not the number of the landmark management information in the list information has reached a predetermined number or more, and the data amount of the list information by the determining means is greater than or equal to a predetermined data amount, or in the list information When it is determined that the number of the landmark management information has reached a predetermined number or more, other information processing is performed as content data that can be acquired via the overlay network, at least a part of the landmark management information in the list information. Generating means for generating a message to be stored in the apparatus, and the information processing apparatus that has received the generated message from the information processing apparatus can acquire the landmark management information via the overlay network It is characterized in that an input process for storing the content data in the other information processing apparatus is performed.

  According to the first, second, ninth to eleventh aspects of the present invention, the information processing apparatus is configured such that the data amount of the list information stored in the storage unit is greater than or equal to a predetermined data amount, or the mark management information in the list information When the number of items exceeds a predetermined number, at least a part of the landmark management information in the list information is stored in other information processing apparatuses as content data that can be acquired via the overlay network. Therefore, even if the number of mark management information registered in the list information increases, the burden on the node device that manages the list information can be reduced.

  According to the third aspect of the present invention, it is possible to transfer the obsolete mark management information whose use frequency is low to another information processing apparatus.

  According to the fourth aspect of the present invention, for example, the mark management information including the mark information given by the same user or the like can be collected and transferred to another information processing apparatus.

  According to the fifth aspect of the present invention, it is possible to collectively transfer the mark management information including the mark information whose output position is assigned in the content data to another information processing apparatus.

  According to the sixth aspect of the present invention, the user can clearly communicate his intention to other users at a desired output position of the content data.

  According to the seventh aspect of the present invention, the location information indicating the location of the content data to which the landmark information is assigned and the list information including the landmark information can be efficiently transmitted to the information processing apparatus.

  According to the invention described in claim 8, the identification information given to the mark management information stored in the other information processing apparatus as the content data and the list information including the mark information are efficiently transmitted to the information processing apparatus. can do.

It is a figure showing an example of outline composition of a contents distribution system concerning this embodiment. (A) is a conceptual diagram showing a mode in which a landmark management information list corresponding to a certain content is managed by one landmark management node in a case where a landmark management information list is generated for each content. (B) is a conceptual diagram showing an aspect in which a landmark management information list corresponding to a certain content is managed by a plurality of landmark management nodes in a case where a landmark management information list is generated for each section of content. (A) is a block diagram showing a schematic configuration example of the content management server MS. (B) is a block diagram showing a schematic configuration example of a node Nn. (A) is a flowchart which shows the registration request process of the mark management information in the control part 11 of a certain node Nn. (B) is a flowchart showing registration processing of landmark management information in the control unit 11 of the landmark management node. (A) is a flowchart which shows the transfer determination process of the mark management information in the control part 11 of a mark management node. (B) is a flowchart showing the process of inputting mark management information content in the control unit 1 of the content management server MS. (A) is a flowchart which shows the reproduction | regeneration processing of the content in the control part 11 of a certain node Nn. (B) is a flow chart showing a mark management information list providing process in the control unit 11 of the mark management node.

  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 which concerns on 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 content management server MS, a user information management device UM, and a plurality of node devices Nn (n = 1, 2, 3,... K). It is prepared for. The content management server MS, the user information management device UM, and each node device Nn are connected to a network NW including the Internet. The content management server MS manages content that can be used by the node device Nn in the content distribution system S. The node device is hereinafter referred to as “node”. Each node Nn is assigned a unique node ID. The node ID is identification information for identifying the node Nn. The node ID is given by a predetermined device connected to the network NW. An example of the predetermined apparatus is a content management server MS. The node Nn is an example of an information processing apparatus according to the present invention.

  Further, the user information management device UM manages attribute information indicating the user ID of the user of the node Nn and the attribute of the user for each user. The user ID is identification information for identifying the user. The user ID is required when managing landmark information described later for each user. Further, the attribute information indicating the user attribute is, for example, a user name or a group name of a group to which the user belongs. The attribute information indicating the user attribute is hereinafter referred to as “user attribute”. Note that the user information management device UM is composed of, for example, a server computer. Alternatively, the user information management device UM may be configured by any node Nn.

  Further, an overlay network ON is formed in the content distribution system S. The overlay network ON is a logical network that forms a virtual link including a plurality of nodes Nn that can communicate with each other via the network. The overlay network ON is realized by a specific algorithm, for example, an algorithm using a distributed hash table. Hereinafter, the distributed hash table is referred to as “DHT (Distributed Hash Table)”. 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 addition, various contents with different contents are distributed and stored in the plurality of nodes Nn participating in the overlay network ON. Examples of content include moving image content that can be viewed by a user, such as a movie or a program. Each content is given a unique content ID. The content ID is identification information for identifying the content. Further, the content ID is given by a predetermined device connected to the network NW.

  In addition, content whose data amount is larger than a predetermined value is divided into a plurality of chunks by dividing at a predetermined time interval. One chunk has a data amount of several megabytes, for example. Each chunk is distributed and stored in a plurality of nodes Nn. For example, the node N1 stores a chunk X1 constituting the content X. The node N2 stores a chunk X2 constituting the content X. There is also a node Nn that stores all the chunks constituting the content X. Each chunk is given a unique chunk ID. The chunk ID is identification information for identifying a chunk. The chunk ID is assigned by a predetermined device connected to the network NW. Further, the chunk ID of each chunk constituting the content is described in, for example, a metafile of the content. The content metafile is a file for searching for each chunk constituting the divided content. In the content metafile, information indicating the correspondence between each chunk in the content is described in association with the chunk ID. The information indicating this correspondence is represented by, for example, the playback order of each chunk in the content or the number of bytes at the head position of each chunk. Each content metafile is distributed and stored in a plurality of nodes Nn. Note that the content ID of the content corresponding to the metafile is given to the metafile.

  A node Nn that stores at least one of content, content metafile, and chunk is hereinafter referred to as a “content holding node”. Information indicating the location of the content, the location of the content metafile, or the location of the chunk is stored as index information in the node Nn that manages the location of the content. The index information is an example of location information indicating the location in the network NW. The node Nn that manages the location of the content is hereinafter referred to as a “root node”. This index information includes a set of node information of a content holding node that stores content or a content metafile and a content ID of the content or content metafile. Alternatively, the index information includes a set of node information of the content holding node that stores the chunk and a chunk ID of the chunk. The node information includes the IP address, port number, and node ID of the content holding node. The root node is determined to be a node Nn to which a node ID closest to the content ID or chunk ID is assigned, for example. The node ID closest to the content ID or chunk ID is, for example, the node ID with the highest number of upper digits that match.

  In such a content distribution system S, the node Nn inquires the root node about the location of the content or the metafile of the content based on the content ID. As a result, the node Nn acquires the inquired content or the metafile of the content from the content holding node via the overlay network ON. Also, the node Nn that has acquired the metafile of the content inquires the root node about the location of each chunk based on each chunk ID described in the metafile. Thereby, the node Nn acquires the inquired chunk from the content holding node via the overlay network ON. The node Nn can reproduce and output the acquired content. Thereby, the user can view the content on the screen. Note that the node Nn can also acquire content, a metafile of content, or a chunk from the content management server MS.

  By the way, it is possible to give mark information indicating a mark to a specific output position in the content. The assignment of the mark information is instructed by the user of the node Nn via the input unit. When the content to which the mark information is assigned is reproduced and output, the mark information is output at the assigned output position. This mark information is information that is used as a bookmark or a sticky note by the user who has given the assignment instruction. Alternatively, the mark information is information for the user who has given the assignment instruction to communicate his intention to other users. More specifically, the landmark information is information such as a character string, sound, still image, moving image, or screen action, and is information that the user can distinguish from the content. Therefore, simple marks, pictograms, etc. can also be used as landmark information. In addition, a certain business operator can instruct to add mark information including predetermined advertisement information in the content as one user of the content. Further, for example, the mark information composed of a character string input by a user becomes comment information that can convey the intention of the user to other users by characters. Further, for example, the landmark information composed of the voice uttered by the user can convey the intention of the user to other users by voice. Examples of screen actions include changing the background color of the screen.

  When mark information is given in a certain content, mark management information is generated. This mark management information includes the content ID of the content, the mark information given in the content, the position information indicating the output position of the mark information, the user ID of the user who has given the assignment instruction, the user attribute, and the like. The landmark management information includes date information on which it is generated. Here, the output position of the mark information is represented by, for example, the time from the playback start position on the playback time axis of the content or the number of bytes. The date information may include year and month and time. The generated landmark management information is transmitted to a predetermined node Nn and managed by the landmark management information list. The mark management information list is an example of list information. Mark information given by a plurality of users' instructions in a certain content can be collectively managed by a mark management information list. The node Nn that manages the mark management information is hereinafter referred to as a “mark management node”. Here, as management of the landmark management information, for example, generation and storage of the landmark management information list, registration of the landmark management information in the landmark management information list, deletion of the landmark management information from the landmark management information list, and to the node Nn Provide a list management information list.

  In addition, the mark management information list may be generated for each content, or may be generated for each section obtained by dividing the time from the content reproduction start position to the end position at a predetermined time interval. Each mark management information list is given a unique list ID. The list ID is identification information for identifying the landmark management information list. In other words, the list ID is identification information for identifying the mark management information registered in the mark management information list. The list ID is given by a predetermined device connected to the network NW. The node Nn having the node ID closest to the list ID assigned to the mark management information list is the mark management node of this mark management information list.

  FIG. 2A is a conceptual diagram showing an aspect in which a landmark management information list corresponding to a certain content is managed by one landmark management node in a case where a landmark management information list is generated for each content. In the example shown in FIG. 2A, the list ID “ABC” assigned to the landmark management information list and the content ID “ABC” of the content corresponding to this landmark management information list are the same. In this case, the content root node of the content ID “ABC” and the landmark management node of the landmark management information list of the list ID “ABC” are the same. Thereby, it is possible to efficiently manage the index information and the landmark management information list.

  The list ID given to the mark management information list may be a hash value determined using the content ID of the corresponding content. This hash value is generated by hashing the content ID with a predetermined hash function. In this case, the content root node and the landmark management node are different.

  On the other hand, FIG. 2B is a conceptual diagram showing an aspect in which a landmark management information list corresponding to a certain content is managed by a plurality of landmark management nodes in a case where a landmark management information list is generated for each section of content. is there. In this case, the list ID given to each landmark management information list is, for example, a hash value of a combination of the content ID of the corresponding content and the time or number of bytes at the start position of each section. This hash value is generated by hashing a combination of the content ID and the time or number of bytes at the start position of each section with a predetermined hash function. The time at the start position of each section is “10′00” ”when the list ID shown in FIG. 2B corresponds to“ AHI ”. By managing the mark management information list corresponding to one content by a plurality of mark management nodes, the load on each mark management node can be reduced. Here, if the start position of each section is made the same as the position where the content is divided in order to generate the above-described chunk, the list ID assigned to the landmark management information list corresponding to each section and the section correspond to this section. The chunk ID can be the same. In this case, the landmark management node of the landmark management information list corresponding to each section is the same as the root node of the chunk corresponding to each section. Thereby, it is possible to efficiently manage the index information and the landmark management information list.

  The list ID given to the mark management information list may be a hash value of the chunk ID of the corresponding chunk. This hash value is generated by hashing the chunk ID with a predetermined hash function. In this case, the chunk root node and the landmark management node are different.

  In some cases, the data amount of the mark management information list managed in the mark management node is greater than or equal to a predetermined data amount, or the number of mark management information in the mark management information list is greater than or equal to a predetermined number. In this case, at least a part of the mark management information in the mark management information list is stored in the other nodes Nn as contents that can be acquired via the overlay network ON. Such content is hereinafter referred to as “mark management information content”.

[ 2. Configuration and function of content management server MS ]
Next, the configuration and function of the content management server MS will be described with reference to FIG. FIG. 3A is a block diagram illustrating a schematic configuration example of the content management server MS. As shown in FIG. 3A, the content management server MS 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.

  The control unit 1 includes a CPU having a calculation function, a working RAM, a ROM, and the like. 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. Further, the storage unit 2 stores the original content that can be used by the node device Nn in the content distribution system S. The storage unit 2 stores content catalog information including content records. In the content record, the content ID, content name, keyword, and the like of the content are described.

  Here, in the case where the mark management information list is generated for each content, the record ID of this content is described in association with the content ID. However, if the content ID of the content and the list ID of the corresponding landmark management information list are the same, it is not necessary to describe the list ID in the content record. Further, as described above, when the list ID is a hash value of the content ID, it is not necessary to describe the list ID in the content record.

  On the other hand, in the case where the landmark management information list is generated for each section of content, the content record describes, for example, the time or number of bytes at the start position of each section obtained by dividing the content at a predetermined time interval. The In this case, the list ID is a hash value of a combination of the content ID of the content and the time or byte count of the start position of the section. However, if the chunk ID of the chunk is the same as the list ID of the corresponding landmark management information list, it is not necessary to describe the list ID in the content record. This is because the chunk ID can be acquired from the content metafile. Further, as described above, when the list ID is a hash value of the chunk ID, it is not necessary to describe the list ID in the content record.

  The content record is generated when the content is input into the content distribution system S. Then, the content catalog information including the generated record is distributed from the content management server MS to each node Nn. Here, the input of content means that a content or a metafile of the content is transmitted and stored in a predetermined node Nn participating in the overlay network ON. The information described in the content metafile may be configured to be described in the content record. In this case, it is not necessary to input the content metafile into the content distribution system S.

  The communication unit 3 controls communication of information with the node Nn and the like through the network NW.

[ 3. Configuration and function of node Nn ]
Next, the configuration and function of the node Nn will be described with reference to FIG. FIG. 3B is a block diagram illustrating a schematic configuration example of the node Nn. As shown in FIG. 3B, the node Nn includes a control unit 11, a storage unit 12, a buffer memory 13, a decoder unit 14, a video processing unit 15, a display unit 16, an audio processing unit 17, a speaker 18, and a communication unit 19. And an input unit 19a and the like. The control unit 11, the storage unit 12, the buffer memory 13, the decoder unit 14, the video processing unit 15, the display unit 16, the audio processing unit 17, the communication unit 19, and the input unit 19a are connected to each other via a bus 19b. Yes. As the node Nn, a personal computer, an STB (Set Top Box), a TV receiver, a karaoke device, or the like is applicable.

  The control unit 11 includes a CPU having a calculation function, a working RAM, a ROM, and the like. And the control part 11 performs the process mentioned later, when CPU reads and runs the various programs memorize | stored in the memory | storage part 12 grade | etc.,. The control unit 11 has a clock function. The control unit 11 is an example of a transmission unit, a determination unit, a determination unit, a generation unit, and an acquisition unit in the present invention.

  The storage unit 12 is composed of, for example, a hard disk drive. The storage unit 12 is an example of a storage unit. The storage unit 12 stores an operating system, a content reproduction program, an information processing program, and the like. Note that the information processing program may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the information processing program may be recorded on a recording medium and read via a drive of the recording medium, for example. In addition, the content reproduction process is performed by the control unit 11 executing the content reproduction program.

  Further, the storage unit 12 stores and stores content acquired from the content holding node or the content management server MS, or a metafile of the content, and further chunks. The storage unit 12 stores an IP address or the like for accessing the content management server MS via the network NW. The storage unit 12 of the node Nn participating in the overlay network ON stores content catalog information, a routing table using DHT, and the like. Further, index information is stored in the storage unit 12 of the root node. In addition, the mark management information list is stored in the storage unit 12 of the mark management node. Further, the storage unit 12 of the mark management node that also serves as the root node stores index information indicating the location of the content to which the mark information is assigned, and a mark management information list including the mark information.

  The buffer memory 13 buffers the received content or chunk. The decoder unit 14 performs a decoding process such as data expansion and decoding of video data and audio data included in the content or chunk in accordance with a command from the control unit 11. The video processing unit 15 performs a predetermined drawing process on the video data decoded by the decoder unit 14 and reproduces and outputs it as a video signal. The display unit 16 displays a video or the like on the screen based on the video signal reproduced and output from the video processing unit 15. The audio processing unit 17 performs D (Digital) / A (Analog) conversion of the audio data decoded by the decoder unit 14 into an analog audio signal, and then amplifies this by an amplifier and outputs it. The speaker 18 outputs the sound signal output from the sound processing unit 17 as a sound wave. When the mark information is given to the content reproduced and output in this way, the mark information is outputted at the given output position. As the output of the mark information, there are a display output to the display unit 16 and an audio output to the speaker 18.

  The communication unit 19 controls communication of information between the content management server MS and other nodes Nn through the network NW. The input unit 19a is an input unit for a user to input an instruction. Examples of the input unit 19a include a mouse, a keyboard, and a recommon. The user can input landmark information to be given from the input unit 19a.

[ 4. Operation of Content Distribution System S ]
Next, the operation of the content distribution system S according to the present embodiment will be described. As a premise of this operation, a user registration operation of the user of the node Nn is performed. In this user registration operation, first, the user operates the input unit 19a of the node Nn to set a user attribute. For example, the user name “user1” and the group name “group1” of the group to which the user belongs are set as user attributes. When the user attribute is set, the node Nn transmits a user registration request message to the user information management device UM via the network NW. This user registration request message is a message for requesting user registration to the user information management apparatus UM. The user registration request message includes the set user attribute. On the other hand, when receiving the user registration request message, the user information management device UM extracts user attributes from the user registration request message. Then, the user information management device UM generates a unique user ID for the extracted user attribute. The user ID is generated, for example, by hashing user attributes with a predetermined hash function. Then, the user information management device UM registers the extracted user attribute and the generated user ID in association with each other in the user information management database. The user ID registered in the user information management database in this manner is returned to this node Nn in response to a request from the node Nn. For example, when the user logs in, the node Nn transmits a user ID request message to the user information management device UM via the network NW. This user ID request message is a message for requesting a user ID from the user information management apparatus UM. The user ID request message includes user attributes input by the user via the input unit 19a. On the other hand, when receiving the user ID request message, the user information management apparatus UM extracts the user attribute from the user ID request message. The user information management device UM acquires a user ID registered in association with the extracted user attribute from the user information management database. Then, the user information management device UM returns a user ID response message including the acquired user ID to the node Nn.

(4-1. Registration operation of landmark management information)
Next, with reference to FIG. 4, the registration operation of the landmark management information will be described. FIG. 4A is a flowchart showing the registration management process for the mark management information in the control unit 11 of a certain node Nn. FIG. 4B is a flowchart showing registration processing of landmark management information in the control unit 11 of the landmark management node. Note that the control unit 11 that performs the processing illustrated in FIG. 4A has already acquired the user ID from the user ID response message returned from the user information management apparatus UM.

  In the process shown in FIG. 4A, when the content selected by the user is reproduced and output, the user moves the predetermined position on the screen of the display unit 16 at the timing when the desired scene is displayed. Click to start. The predetermined position is, for example, a position where the user wants to add mark information on a frame of content displayed on the screen. Alternatively, the predetermined position may be a display position of a slider that moves on a seek bar displayed on the screen. The slider indicates the current playback position from the beginning to the end of the content.

  When the process shown in FIG. 4A is started, the control unit 11 of the node Nn includes mark information indicating a mark provided in the content in response to an assignment instruction from the user via the input unit 19a. Position information indicating the output position of the mark information is acquired (step S1). For example, comment information or advertisement information input by the user via the input unit 19a in the comment input field displayed on the screen of the display unit 16 is acquired as the mark information. Alternatively, an image file selected by the user via the input unit 19a from among still image or moving image image files stored in advance in the storage unit 12 is acquired as the mark information. Alternatively, an audio file selected by the user via the input unit 19a from the audio files stored in advance in the storage unit 12 is acquired as the mark information. This audio file is, for example, a file in which sound that has been pronounced by the user in advance is recorded. In addition, when the user clicks a predetermined position on the screen of the display unit 16 with, for example, a mouse, the control unit 11 is configured to add a simple mark or pictograph stored in advance as landmark information. Also good.

  Further, the output position of the mark information corresponds to the content reproduction position at the timing when the user clicks the predetermined position on the screen with, for example, the mouse. Further, the position information indicating the output position is represented, for example, by the time from the beginning or the number of bytes on the content reproduction time axis.

  Next, the control unit 11 generates mark management information including the mark information and the position information acquired in step S1 (step S2). The mark management information includes the content ID of the content to which the mark information is assigned, the user attribute input by the user, the user ID extracted from the user ID response message, and the date information on which the mark management information is generated. It is.

  Next, the control unit 11 acquires the list ID of the mark management information list in which the mark management information generated in step S2 is to be registered (step S3). This list ID is acquired based on the content ID of the content to which the mark information is assigned or the chunk IDs of the chunks constituting the content. Here, the method of acquiring the list ID will be described separately for (a) a case where a mark management information list is generated for each content and (b) a case where a mark management information list is generated for each section of content. . Note that which case is adopted in the node Nn is uniformly determined on the content distribution system S.

(A) Case in which mark management information list is generated for each content In case (a), the content ID of the content to which the mark information is assigned or the hash value of this content ID is acquired as the list ID. Or you may comprise so that list ID matched with content ID of the content to which landmark information was provided may be acquired from the record of content in content catalog information.

(B) Case where the mark management information list is generated for each section of content In the case of (b), the chunk corresponding to the section including the output position of the mark information from the metafile of the content to which the mark information is added Chunk ID is acquired. Then, the acquired chunk ID or the hash value of this chunk ID is acquired as a list ID. Alternatively, the time or byte count of the start position of each section associated with the content ID of the content to which the landmark information is assigned is acquired from the content record in the content catalog information. Then, a hash value of a combination of the content ID of the content to which the landmark information is added and the time or the number of bytes of the start position of the section including the landmark information output position is acquired as the list ID.

  Next, the control unit 11 generates a mark management information registration request message (step S4). The mark management information registration request message is a message for requesting the mark management node to register the mark management information in the list. The mark management information registration request message includes the mark management information generated in step S2 and the list ID acquired in step S3.

  Next, the control unit 11 transmits the mark management information registration request message generated in step S4 to the mark management node, for example, by DHT routing using the list ID acquired in step S3 as a key (step S5), the process ends. The DHT routing is known in, for example, Japanese Patent Application Laid-Open No. 2007-053662, and detailed description thereof is omitted.

  The landmark management node that has received the landmark management information registration request message thus transmitted starts the process shown in FIG. When the process shown in FIG. 4B is started, the control unit 11 of the landmark management node acquires the landmark management information and the list ID from the received landmark management information registration request message (step S11).

  Next, the control unit 11 of the landmark management node determines whether or not the landmark management information list corresponding to the list ID acquired in step S11 is already generated and stored in the storage unit 12 (step S12). If the control unit 11 determines that the landmark management information list corresponding to the acquired list ID is not stored in the storage unit 12 (step S12: NO), the control unit 11 proceeds to step S13. On the other hand, if the control unit 11 determines that the mark management information list corresponding to the acquired list ID is stored in the storage unit 12 (step S12: YES), the control unit 11 proceeds to step S14.

  In step S13, the control unit 11 of the landmark management node newly generates a landmark management information list corresponding to the list ID acquired in step S11. Then, the control unit 11 of the landmark management node stores the generated landmark management information list in the storage unit 12 in association with the list ID acquired in step S11.

  In step S14, the control unit 11 of the landmark management node registers the landmark management information acquired in step S11 in the landmark management information list corresponding to the list ID acquired in step S11, and ends the process. Here, the mark management information includes date information on which the mark management information is registered. The date information may include year and month and time. In addition, when the mark information is newly added to the content stored in any of the nodes Nn, the control unit 11 of the mark management node causes the new mark information and its mark information to be registered by the mark management information registration operation. The landmark management information including the position information is acquired. Then, the control unit 11 of the mark management node additionally registers the acquired mark management information in the mark management information list.

  As described above, according to the registration operation of the landmark management information, each landmark management information including the landmark information assigned to a certain content is registered in the landmark management information list in accordance with the user's assignment instruction of each node Nn and collectively managed. can do.

(4-2. Transfer operation of landmark management information)
Next, with reference to FIG. 5, the transfer operation of the mark management information is described. The mark management information transfer operation is an operation for transferring the management of the mark management information registered in the mark management information list of the mark management node to another node Nn. FIG. 5A is a flowchart showing the transfer management determination process of the mark management information in the control unit 11 of the mark management node. FIG. 5B is a flowchart showing the process of inputting the mark management information content in the control unit 1 of the content management server MS.

  The process illustrated in FIG. 5A is started, for example, every predetermined period or immediately after the process illustrated in FIG. When the process shown in FIG. 5A is started, the control unit 11 of the landmark management node determines whether or not the data amount of the landmark management information list stored in the storage unit 12 is equal to or greater than a predetermined data amount. (Step S21). Here, the predetermined data amount is set in advance in consideration of the load of the control unit 11 of the landmark management node. For example, it is set to about 10 kbytes.

  When the control unit 11 of the landmark management node determines that the data amount of the landmark management information list stored in the storage unit 12 is equal to or greater than the predetermined data amount (step S21: YES), the process proceeds to step S22. . When the control unit 11 of the landmark management node determines that the data amount of the landmark management information list stored in the storage unit 12 is not equal to or greater than the predetermined data amount (step S21: NO), the process ends. .

  In step S21, it is determined whether or not “the number of registered mark management information in the mark management information list is equal to or greater than a predetermined number” instead of “the data amount of the mark management information list is equal to or greater than the predetermined data amount”. You may comprise so that. In this case, when the control unit 11 of the mark management node determines that the number of registrations of the mark management information in the mark management information list stored in the storage unit 12 has become a predetermined number or more (step S21: YES), step Proceed to S22. Here, the predetermined number is set in advance in consideration of the load on the control unit 11 of the landmark management node.

  In step S22, the control unit 11 of the landmark management node determines at least some landmark management information from the landmark management information list. The landmark management information determined in step S22 is landmark management information to be transferred to another node Nn. For example, the control unit 11 leaves a part of the mark management information in the mark management information list in the mark management information list. Then, the control unit 11 determines a predetermined number or a predetermined data amount of other mark management information excluding a part of the mark management information to be left in the mark management information list. Here, the predetermined number or the predetermined data amount may be the same as the predetermined number or the predetermined data amount determined in step S21.

  Next, the control unit 11 of the landmark management node generates one or more new landmark management information lists for registering the landmark management information to be transferred. Then, the control unit 11 registers the landmark management information determined in step S22 in a new landmark management information list (step S23). The registered landmark management information is deleted from the original landmark management information list.

  Here, examples of the mark management information determined in step S22 include the following (X1) to (X3).

(X1) Mark management information generated or registered before a date that is a predetermined period after the current date
In the case of (X1), the control unit 11 refers to the date information included in each mark management information, and uses the mark management information list to generate the mark management information generated or registered before the date that is a predetermined period after the current date. decide. An example of this predetermined period is about 3 days. In the case of (X1), it is possible to transfer the obsolete landmark management information, which is less frequently used, to another node Nn.

(X2) Mark management information including specific user ID or specific user attribute
In the case of (X2), the control unit 11 acquires a specific user ID or a specific user attribute as condition information for determining the mark management information from the mark management information list. Such a specific user ID or specific user attribute is set by, for example, an administrator and stored in the storage unit 12. And the control part 11 determines the mark management information containing the specific user ID or specific user attribute acquired as condition information from a mark management information list. According to the case of (X2), the landmark management information including the landmark information given by the same user or users belonging to the same group can be collectively transferred to another node Nn. Note that a plurality of specific user IDs or specific user attributes may be set. In this case, in step S23, a new landmark management information list corresponding to each specific user ID or each specific user attribute is generated. In the generated mark management information list, the mark management information corresponding to each specific user ID or each specific user attribute is registered.

(X3) Mark management information including mark information given within a specific section of each section of content
In the case of (X3), the control unit 11 uses, as condition information for determining the mark management information from the mark management information list, among the sections obtained by dividing the time from the output start position to the end position of the content at predetermined time intervals. Section information indicating a specific section is acquired. And the control part 11 determines the landmark management information containing the landmark information provided in the specific area shown by the area information acquired as condition information with reference to the positional information contained in each landmark management information . As an example of this specific section, there is a section in which the number of assigned landmark information is a predetermined number or more. In this case, using the position information of the mark information included in each mark management information in the mark management information list, the number of the given mark information is counted for each content section. In the case of (X3), the mark management information including the mark information whose output position is assigned in the content can be collectively transferred to another node Nn. Note that a plurality of the specific sections may be set. In this case, in step S23, a new landmark management information list corresponding to each specific section is generated. For example, a landmark management information list corresponding to a section in which the landmark information output position is 0 second to 60 seconds and a landmark management information list corresponding to a section in which the landmark information output position is 60 seconds to 120 seconds are generated. The In the generated mark management information list, the mark management information corresponding to each specific section is registered.

  The mark management information may be determined by a method different from the above (X1) to (X3). For example, a predetermined number of pieces of landmark management information registered in the original landmark management information list may be determined at random.

  The landmark management information determined in step S22 may be all the landmark management information currently registered in the original landmark management information list.

  Next, the control unit 11 generates a mark management information content input request message (step S24). The mark management information content input request message is a message for storing at least a part of the mark management information in the mark management information list in the other nodes Nn as contents that can be acquired via the overlay network ON. The insertion request message includes the list ID of the original landmark management information list in which the landmark management information determined in step S22 is registered, a new landmark management information list for registering the determined landmark management information, and the like. included. If a plurality of mark management information lists are generated, each mark management information list is included in the input request message. In this case, for example, a serial number is assigned to each mark management information list.

  Next, the control unit 11 accesses the content management server MS and transmits the generated input request message via the network NW (step S25).

  The content management server MS that has received the input request message thus transmitted starts the processing shown in FIG. When the processing shown in FIG. 5B is started, the control unit 1 of the content management server MS acquires the mark management information list and the list ID from the received insertion request message (step S31).

  Next, the control unit 1 of the content management server MS generates the mark management information content by compressing the mark management information list acquired from the insertion request message (step S32). When a plurality of mark management information lists are acquired from the input request message, mark management information contents are generated for each mark management information list.

  Next, the control unit 1 of the content management server MS assigns a unique content ID to the generated landmark management information content (step S33). The content ID assigned to the mark management information content may be, for example, a hash value of the list ID acquired from the input request message. When a plurality of landmark management information contents are generated, a unique content ID is assigned to each landmark management information content. For example, the hash value may be a combination of a list ID and a serial number assigned to the landmark management information list.

  Next, the control unit 1 of the content management server MS performs an input process for inputting the mark management information content assigned with the content ID into the content distribution system S (step S34). This input process is a process of storing the mark management information content provided with the content ID in other nodes Nn as content that can be acquired via the overlay network ON. When a plurality of landmark management information contents are generated, the insertion process is performed for each landmark management information content. In the input process, the control unit 1 selects a predetermined number of nodes Nn from among the nodes Nn storing node information in the storage unit 2 among the nodes Nn participating in the overlay network ON. And the control part 1 accesses each selected node Nn, and transmits the said mark management information content. The node Nn stores and saves the received landmark management information content in the storage unit 12. Thus, the landmark management information determined in step S22 is transferred to another node Nn. However, the management in this node Nn is only the storage of the mark management information content including the mark management information and the provision of the mark management information content to other nodes Nn.

  Each node Nn that stores the mark management information content executes publish processing as a content holding node. This publishing process is a process for publishing to other nodes Nn that the mark management information content is stored. In this publishing process, the content holding node generates a publish message. The publish message includes the content ID of the landmark management information content, the IP address of the content holding node, and the like. It is transmitted to the root node by DHT routing using the content ID as a key. Then, the root node that has received the publish message stores a set of the content ID of the mark management information content and the IP address of the content holding node in the index cache area of the storage unit 12 as index information.

  Next, the control unit 1 of the content management server MS returns a content ID response message to the mark management node that has transmitted the mark management information content input request message (step S35), and ends the process. The content ID response message includes the content ID assigned to the landmark management information content in step S33.

  When receiving the content ID response message from the content management server MS (step S26), the control unit 11 of the mark management node acquires the content ID of the mark management information content from the content ID response message. Next, the control unit 11 stores the acquired content ID of the landmark management information content in association with the landmark management information list (step S27), and ends the process. This landmark management information list is a landmark management information list from which the landmark management information determined in step S22 is deleted. When a plurality of landmark management information contents are input, the content ID of each landmark management information content is stored in association with the landmark management information list.

  Thus, according to the transfer operation of the landmark management information, the burden on the landmark management node can be reduced.

  When the transfer determination process shown in FIG. 5A is executed at predetermined time intervals (for example, 3 days), the process of step S21 is not performed and the process of step S22 is performed. good.

(4-3. Reproduction Operation of Content with Mark Information)
Next, with reference to FIG. 6, description will be given of a reproduction operation of content to which landmark information is added.

  FIG. 6A is a flowchart showing content reproduction processing in the control unit 11 of a certain node Nn. FIG. 6B is a flowchart showing a mark management information list providing process in the control unit 11 of the mark management node. Note that the control unit 11 that performs the process illustrated in FIG. 6A has already acquired the user ID from the user ID response message returned from the user information management apparatus UM.

  The process shown in FIG. 6A is started when the control unit 11 of the node Nn acquires a content ID by the user's operation of the input unit 19a. Here, the content ID can be acquired from, for example, a Web page provided by the node Nn accessing the content providing site. This content providing site is, for example, a Web site for providing moving image content. Alternatively, the content ID may be searched by a keyword or the like from the content catalog information stored in the node Nn.

  When the process shown in FIG. 6A is started, the control unit 11 acquires a list ID of the landmark management information list corresponding to the content of the acquired content ID (step S41). Also in this case, as in step S22, the list ID acquisition method includes (a) a case where the mark management information list is generated for each content and (b) a case where the mark management information list is generated for each section of the content. Is different.

  In the case of (a), the acquired content ID or the hash value of this content ID is acquired as the list ID. Or you may comprise so that list ID matched with content ID of the acquired content may be acquired from the record of the content in content catalog information.

  In the case (b), the chunk ID of each chunk described in the metafile of the content corresponding to the acquired content ID or the hash value of each chunk ID is acquired as the list ID. In this case, based on the acquired content ID, a metafile of the content is acquired in advance from a content holding node or the like. Alternatively, the time or the number of bytes at the start position of each section associated with the content ID of the content is acquired from the content record in the content catalog information. Then, a hash value of a combination of the content ID of the acquired content and the time or byte count of the start position of the acquired section is acquired for each section as a list ID.

  Next, the control unit 11 generates a mark management information list request message (step S42). The mark management information list request message is a message requesting the mark management information list to the mark management node. The mark management information list request message includes the IP address and port number of the node Nn that transmits the message, the list ID acquired in step S41, and the like. As described above, when the list ID and the content ID are the same, or when the list ID and the chunk ID are the same, the landmark management node and the root node are the same. In these cases, the mark management information list request message includes request information for index information managed by the root node.

  Next, the control unit 11 transmits the landmark management information list request message generated in step S42 to the landmark management node, for example, by DHT routing using the list ID acquired in step S41 as a key (step S41). S43). In the case of (b) above, a landmark management information list request message is transmitted to each landmark management node corresponding to each content section.

  The landmark management node that has received the landmark management information list request message thus transmitted starts the process shown in FIG. When the process shown in FIG. 6B is started, the control unit 11 of the landmark management node acquires a list ID from the received landmark management information list request message (step S61).

  Next, the control unit 11 of the landmark management node acquires the landmark management information list corresponding to the list ID acquired in step S61 from the storage unit 12 (step S62). At this time, the content ID of the mark management information content may be stored in association with the mark management information list. In this case, the control unit 11 of the landmark management node acquires the content ID of the landmark management information content from the storage unit 12.

  Next, the control unit 11 of the landmark management node determines whether or not index information request information is included in the received landmark management information list request message (step S63). When the landmark management node and the root node are the same, the landmark management information list request message includes request information for index information. If the control unit 11 determines that the index management information list request message does not include the index information request information (step S63: NO), the control unit 11 proceeds to step S65. On the other hand, when it is determined that the mark management information list request message includes the index information request information (step S63: YES), the control unit 11 sets the index information corresponding to the list ID acquired in step S61. It acquires from the memory | storage part 12 (step S64), and progresses to step S65. That is, when the list ID and the content ID are the same, or when the list ID and the chunk ID are the same, index information corresponding to the list ID is acquired.

  In step S65, the control unit 11 of the landmark management node generates a landmark management information list provision message. The mark management information list provision message is a message for transmitting the mark management information list to the node Nn in response to a request for the mark management information list from the node Nn. This mark management information list provision message includes the mark management information list acquired in step S62. When the content ID of the mark management information content is acquired in step S62, the content ID of the mark management information content is also included in the mark management information list provision message. Thereby, the mark management information list and the content ID of the mark management information content can be efficiently transmitted to the requested node Nn. Further, when index information is acquired in step S64, the index information is also included in the mark management information list provision message. Thereby, the landmark management information list and the index information can be efficiently transmitted to the requested node Nn.

  Next, the control unit 11 of the landmark management node returns the landmark management information list provision message generated in step S65 to the node Nn that is the source of the landmark management information list request message (step 66), and ends the process. .

  Returning to the processing of FIG. 6A, the control unit 11 of the node Nn receives the mark management information list provision message returned from the mark management node (step S44). In the case of (b), the mark management information list provision message returned from each mark management node is received.

  Next, the control unit 11 acquires a landmark management information list from the received landmark management information list provision message (step S45). That is, when content is requested, a landmark management information list for registering landmark management information is acquired. Here, “when content is requested” means before or after the content or metafile of the content is requested from the content holding node. Here, when the content ID of the mark management information content is included in the mark management information list provision message, this content ID is also acquired. In this case, the control unit 11 executes processing for acquiring the landmark management information content corresponding to the content ID. This acquisition process is a process of acquiring the landmark management information content based on the content ID of the landmark management information content. In this acquisition process, first, the control unit 11 generates a content location inquiry message. The content location inquiry message is a message for inquiring the location of the mark management information content to the root node. Then, the control unit 11 transmits the generated content location inquiry message to the root node of the mark management information content by DHT routing using the content ID as a key. Thereby, the index information returned from the root node is acquired. In this way, the control unit 11 that has acquired the index information accesses the content holding node based on the IP address of the content holding node included in the index information. Then, the control unit 11 downloads the mark management information content from the content holding node. The control unit 11 decompresses the downloaded landmark management information content and extracts the landmark management information list. The landmark management information in the landmark management information list extracted in this way is incorporated into the landmark management information list acquired in step S45.

  In addition, when index information is included in the mark management information list provision message, this index information is also acquired.

  Next, the control unit 11 determines whether or not the content corresponding to the content ID acquired at the start of the process in FIG. 6A is stored in the storage unit 12 (step S46). If the control unit 11 determines that the content corresponding to the content ID is stored (step S46: YES), the control unit 11 proceeds to step S49. On the other hand, when the control unit 11 determines that the content corresponding to the content ID is not stored (step S46: NO), the control unit 11 proceeds to step S47.

  In step S47, the control unit 11 determines whether or not the metafile of the content corresponding to the content ID acquired at the start of the process in FIG. If the control unit 11 determines that the metafile of the content corresponding to the content ID is stored (step S47: YES), the control unit 11 proceeds to step S48. On the other hand, when the control unit 11 determines that the content metafile corresponding to the content ID is not stored (step S47: NO), the control unit 11 proceeds to step S50.

  In step S48, the control unit 11 executes chunk acquisition processing corresponding to each chunk ID described in the content metafile acquired at the start of processing in FIG. This acquisition process is a process of acquiring a chunk from the content holding node based on the chunk ID of the chunk. In this acquisition process, first, the control unit 11 determines whether or not the index information corresponding to the chunk ID has already been acquired, and if not acquired, generates a content location inquiry message. The content location inquiry message is a message for inquiring the location of the chunk to the root node. Then, the control unit 11 transmits the generated content location inquiry message to the root node of the chunk by DHT routing using the chunk ID as a key. Thereby, the index information returned from the root node is acquired. On the other hand, when the index information corresponding to the list ID has already been acquired in step S45, the control unit 11 does not need to generate and transmit the content location inquiry message. In this way, the control unit 11 that has acquired the index information accesses the content holding node based on the IP address of the content holding node included in the index information. Then, the control unit 11 downloads the chunk from the content holding node. Download is an example of acquisition. Each chunk downloaded in this way is buffered in the buffer memory 13.

  In step S49, the control unit 11 executes content acquisition processing corresponding to the content ID acquired at the start of processing in FIG. This acquisition process is a process of acquiring a content or a metafile of the content based on the content ID of the content. In this acquisition process, first, the control unit 11 determines whether or not the index information corresponding to the content ID has already been acquired. If not, the control unit 11 generates a content location inquiry message. The content location inquiry message is a message for inquiring the location of the content or the metafile of the content to the root node. By transmitting the content location inquiry message, the index information is acquired from the root node as in step S48. On the other hand, when the index information corresponding to the list ID has already been acquired in step S45, the control unit 11 does not need to generate and transmit the content location inquiry message.

  In this way, the control unit 11 that has acquired the index information accesses the content holding node based on the IP address of the content holding node included in the index information. Then, the control unit 11 downloads the content or the content metafile from the content holding node. The content downloaded in this way is buffered in the buffer memory 13. When the content metafile is downloaded, each chunk is downloaded from the content holding node via the overlay network ON based on each chunk ID described in the content metafile, as in step S48. . The downloaded chunk is buffered in the buffer memory 13.

  Next, the control unit 11 executes a content reproduction process (step S50). In the content reproduction process, the content buffered in the buffer memory 13 is sent to the decoder unit 14 to perform reproduction control for reproduction. Each chunk may be buffered in the buffer memory 13 in some cases. In this case, the control unit 11 refers to the metafile of the content and sends each buffered chunk to the decoder unit 14 based on, for example, the playback order of each chunk. In the reproduction control, the control unit 11 outputs the mark information included in the mark management information registered in the mark management information list acquired in step S45 at the output position in the content to which the mark management information is assigned. Note that the content reproduction process ends when the reproduction of the content is completed or when a reproduction stop instruction is given by the user.

  Note that mark information may be given by many users in the content to be played back. In this case, if all these pieces of landmark information are output during the reproduction of the content, it becomes difficult for the user viewing the content to view the content and the landmark information. Therefore, the mark management information to be output from the mark management information list may be narrowed down according to the condition for determining the mark management information including the mark information to be output during the reproduction of the content.

  As described above, according to the above-described embodiment, the landmark management node has the data amount of the landmark management information list equal to or larger than the predetermined data amount, or the registered number of landmark management information in the landmark management information list is equal to or larger than the predetermined number. In this case, at least a part of the mark management information in the mark management information list is stored in other nodes Nn as the mark management information content that can be acquired via the overlay network ON. Therefore, even if the number of mark management information registered in the mark management information list increases, the burden on the mark management node that manages the mark management information list can be reduced.

  In the above embodiment, the mark management information including the mark information assigned to the content in each node Nn is managed by the mark management node. As another example of this configuration, the location information indicating the location of the node Nn storing the location management information in the network NW may be managed by the location management node instead of the location management information.

  The node Nn that stores the mark management information is a node Nn that adds the mark information to the content. An example of the location information is the node ID of the node Nn. In the case of this configuration, the mark management information registration request message transmitted to the mark management node in step S5 shown in FIG. 4A includes the node ID of the node Nn that generated the mark management information.

  In step S14 shown in FIG. 4B, the node ID acquired from the mark management information registration request message is registered in the mark management information list. Also in this case, the mark management information content including the node ID of the node Nn that generated the mark management information is generated under a predetermined condition by the transfer operation of the mark management information. The generated landmark management information content is stored in the node Nn as content that can be acquired via the overlay network ON by the input processing of the content management server MS.

  In step S45 shown in FIG. 6A, the control unit 11 acquires the node ID of each node Nn that stores the mark management information from the mark management information list. At this time, when the content ID of the mark management information content is included in the mark management information list provision message, the mark management information content acquisition process corresponding to the content ID is performed. Thus, the node ID of each node Nn that stores the mark management information is acquired from the mark management information list in the acquired mark management information content.

  Next, the control unit 11 generates a mark management information request message corresponding to each acquired node ID. The mark management information request message is a message for requesting mark management information to the node Nn that stores the mark management information. This mark management information request message includes the node ID acquired from the mark management information list, the IP address and port number of the node Nn that transmits this message, and the content ID. This content ID is the content ID acquired at the start of the process shown in FIG.

  Next, the control unit 11 transmits the generated mark management information request message to each node Nn storing the mark management information by DHT routing using the node ID included in the message as a key. The control unit 11 of each node Nn that has received the mark management information request message thus transmitted acquires the content ID from the mark management information request message. Next, the control unit 11 of each node Nn acquires the mark management information including the acquired content ID from the storage unit 12. Next, the control unit 11 of each node Nn returns a mark management information providing message including the acquired mark management information to the node Nn that is the source of the mark management information request message.

  The control unit 11 of the node Nn that has received each mark management information providing message transmitted in this manner acquires the mark management information from each mark management information request message. Then, the control unit 11 of the node Nn registers each acquired landmark management information in the landmark management information list. After this registration, the processing after step S46 shown in FIG.

  According to such a configuration, since the landmark management node manages the node ID of the node Nn that stores the landmark management information, the storage capacity required for management can be reduced compared to managing the landmark management information itself. it can. The landmark management node may be configured to manage the IP address and port number of the node Nn storing the landmark management information.

  In the above embodiment, the landmark information is configured to be managed by the landmark management node for each content or for a plurality of sections of the content. As another example of this configuration, the mark management information may be managed by, for example, the content management server MS.

  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.

DESCRIPTION OF SYMBOLS 1 Control part 2 Storage part 3 Communication part 4 Bus 11 Control part 12 Storage part 13 Buffer memory 14 Decoder part 15 Video | video process part 16 Display part 17 Audio | voice processing part 18 Speaker 19 Communication part 19a Input part 19b Bus MS Content management server UM User Information management device Nn node NW network ON overlay network S content distribution system

Claims (11)

Content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network, and each information processing device receives other information via the overlay network. An information processing apparatus in a distribution system configured to acquire the content data from a processing apparatus,
Storage means for storing list information for registering one or more mark management information including mark information indicating a mark given in the content data and position information indicating an output position of the mark information;
In response to a request from another information processing apparatus, transmission means for transmitting the list information to the other information processing apparatus;
Determining means for determining whether the data amount of the list information stored in the storage means is equal to or greater than a predetermined data amount, or whether the number of the landmark management information in the list information is equal to or greater than a predetermined number;
When the determination means determines that the data amount of the list information is equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than a predetermined number, at least a part of the list information Generating means for generating a message for storing in the other information processing apparatus as content data that can be acquired via the overlay network;
An information processing apparatus comprising: A determination means for leaving a part of the mark management information in the list information from the list information in the list information and determining other mark management information excluding the part of the mark management information;
The generation unit generates a message for storing the mark management information determined by the determination unit in another information processing apparatus as content data that can be acquired via the overlay network. The information processing apparatus described in 1. The landmark management information includes date information indicating a date when the landmark management information is registered in the list information,
The determination means refers to the date information included in the landmark management information, and determines the landmark management information registered before the date retroactive for a predetermined period from the current date from the list information. Item 3. The information processing device according to Item 2. The landmark management information includes identification information for identifying a user who gives an instruction to give the landmark information or attribute information indicating a user attribute,
As condition information for determining the landmark management information from the list information, the information processing apparatus further includes an acquisition unit that acquires identification information for identifying a user or attribute information indicating a user attribute,
The information processing apparatus according to claim 2, wherein the determination unit determines the mark management information including the identification information or the attribute information acquired as the condition information from the list information. As condition information for determining the landmark management information from the list information, section information indicating one or more sections among the sections obtained by dividing the time from the output start position to the end position of the content at predetermined time intervals. It further comprises an acquisition means for acquiring,
The determining means refers to position information indicating an output position of the mark information included in the mark management information, and includes mark information given in a section indicated by the section information acquired as the condition information. The information processing apparatus according to claim 2, wherein landmark management information is determined from the list information.   The information processing apparatus according to claim 1, wherein the mark information is comment information input from an input unit of the information processing apparatus by the user. The storage means stores location information indicating the location of the content data to which the landmark information included in the landmark management information is added,
The said transmission means transmits the said location information to the said information processing apparatus, when transmitting the said list information to the said information processing apparatus according to the said request | requirement. The information processing apparatus according to item. The mark management information stored in the other information processing apparatus as the content data is given unique identification information for identifying the content data in the overlay network by a predetermined apparatus connected to the network. And
The storage means stores the identification information given to the landmark management information stored in the other information processing apparatus as the content data from the list information,
The said transmission means transmits the said identification information to the said information processing apparatus, when transmitting the said list information to the said information processing apparatus according to the said request | requirement. The information processing apparatus according to item. Content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network, and each information processing device receives other information via the overlay network. A computer included in an information processing apparatus in a distribution system configured to acquire the content data from a processing apparatus,
Storing list information for registering one or more mark management information including mark information indicating a mark given in the content data and position information indicating an output position of the mark information;
In response to a request from another information processing apparatus, transmitting the list information to the other information processing apparatus;
Determining whether the data amount of the stored list information is equal to or greater than a predetermined data amount, or whether the number of the landmark management information in the list information is equal to or greater than a predetermined number;
When it is determined that the data amount of the list information is equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than the predetermined number, at least a part of the landmark management in the list information Generating a message for storing information in other information processing apparatus as content data obtainable via the overlay network;
Information processing program to execute. Content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network, and each information processing device receives other information via the overlay network. A landmark information management method in a distribution system configured to acquire the content data from a processing device,
Storing the list information in which the information processing apparatus registers one or more mark management information including mark information indicating a mark given in the content data and position information indicating an output position of the mark information;
The information processing apparatus, in response to a request from another information processing apparatus, transmitting the list information to the other information processing apparatus;
The information processing apparatus determines whether the data amount of the stored list information is equal to or greater than a predetermined data amount, or whether the number of landmark management information in the list information is equal to or greater than a predetermined number;
When the information processing apparatus determines that the data amount of the list information is equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than a predetermined number, at least the list information Generating a message for storing a part of the landmark management information in another information processing apparatus as content data obtainable via the overlay network;
A landmark information management method comprising: Content data is stored in one or more information processing devices in an overlay network composed of a plurality of information processing devices that can communicate with each other via a network, and each information processing device receives other information via the overlay network. In a distribution system configured to acquire the content data from a processing device,
The information providing device includes:
Storage means for storing list information for registering one or more mark management information including mark information indicating a mark given in the content data and position information indicating an output position of the mark information;
In response to a request from another information processing apparatus, transmission means for transmitting the list information to the other information processing apparatus;
Determining means for determining whether the data amount of the list information stored in the storage means is equal to or greater than a predetermined data amount, or whether the number of the landmark management information in the list information is equal to or greater than a predetermined number;
When the determination means determines that the data amount of the list information is equal to or greater than a predetermined data amount, or the number of the landmark management information in the list information is equal to or greater than a predetermined number, at least a part of the list information Generating means for generating a message for storing in the other information processing apparatus as content data that can be acquired via the overlay network;
With
The information processing apparatus that has received the generated message from the information processing apparatus performs a process of storing the mark management information in the other information processing apparatus as content data that can be acquired via the overlay network. A distribution system characterized by

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