JP5154464B2 - Metadata delivery system and metadata delivery method - Google Patents

Description

  The present invention relates to a metadata distribution system and a metadata distribution method for distributing content metadata to a user terminal.

  In IPTV (Internet Protocol TeleVision) that provides digital TV broadcasting and VoD (Video on Demand), program content data is transmitted to a user terminal as a video receiver via a network such as the Internet. Conventionally, in such IPTV, a metadata distribution server distributes metadata describing information on a program (content) by unicast in response to a request from a user terminal.

  On the other hand, in Patent Document 1, when a broadcast communication device that transmits data to a plurality of receiving terminals by broadcast receives a retransmission request from any of the receiving terminals by unicast, it is designated by this retransmission request. It is described that the transmitted data is retransmitted by unicast.

JP 2003-224601 A

  In the case of the above-described conventional IPTV, the more popular the program, the more metadata transmission requests and the higher the load on the metadata distribution server. Therefore, it is conceivable to apply the technique of Patent Document 1 and distribute metadata by broadcast. However, when the metadata of all programs is transmitted by broadcast, the metadata of programs that are not in high demand is also distributed to all user terminals, and the memory load on the user terminals is likely not to be viewed. It will increase with the data.

  The present invention has been made in view of the above circumstances, and its purpose is to reduce the load on a metadata distribution server that distributes metadata of content and a user terminal that receives and displays the metadata. However, an object is to provide a metadata distribution system and a metadata distribution method capable of distributing metadata.

  In order to solve the above-described problems, the present invention provides a multicast distribution device that distributes summary metadata indicating a summary description of content and detailed metadata indicating a detailed description of content by multicast, and distributes detailed metadata by unicast. A unicast distribution device, a determination device that selects content to which detailed metadata is to be transmitted by multicast, and a user terminal device that displays the summary metadata and the detailed metadata are connected via a network. In the metadata distribution system, the summary metadata includes content identification information and a summary description of the content, and the detailed metadata includes content identification information and a detailed description of the content, and the multicast The distribution device includes the summary metadata, and A multicast distribution device storage unit that stores the detailed metadata, the summary metadata stored in the multicast distribution device storage unit, and a metadata distribution unit that distributes the detailed metadata to the terminal device by multicast. A metadata writing unit that receives the detailed metadata to be distributed by multicast and writes the detailed metadata to the multicast distribution device storage unit, and the terminal device stores the summary metadata and the detailed metadata The terminal device storage unit, the summary metadata and the detailed metadata distributed by multicast from the multicast distribution device are written to the terminal device storage unit, and the detailed metadata distributed from the unicast distribution device by unicast Data is stored in the terminal device storage unit The distribution data receiving unit for writing, the summary metadata display control unit for displaying the summary metadata read from the terminal device storage unit, and the summary metadata displayed by the summary metadata display control unit by the user In response to the input of the selected summary metadata, when the detailed metadata in which the identification information of the content in the selected summary metadata is set is not stored in the terminal device storage unit, to the unicast distribution device A distribution request unit that transmits a detailed metadata distribution request in which content identification information is set, and the detailed metadata specified by the content identification information in the selected summary metadata is read from the terminal device storage unit A detailed metadata display control unit to be displayed, and the unicast distribution device includes the detailed metadata A unicast distribution device storage unit that stores the detailed metadata distribution request from the terminal device, and the detailed metadata specified by the content identification information acquired from the detailed metadata distribution request. A detailed metadata delivery unit that reads out from the storage unit and returns it by unicast; a detailed metadata delivery notification unit that notifies the determination device of identification information of the content to which the detailed metadata delivery unit has returned the detailed metadata; The determination device includes a content related information table including a plurality of records including content identification information, related information of the content, and the number of distributions of the detailed metadata of the content by the unicast distribution device. A storage unit for storing content identification information from the unicast distribution device An update unit that receives and updates the number of detailed metadata distributions in the content related information table corresponding to the identification information of the content, and a record in the content related information table in which the number of detailed metadata distributions is a predetermined number or more. Based on the related information of the identified record that has been identified, a condition for selecting a record of content to which detailed metadata should be transmitted by multicast is generated, and from other records that include the related information that matches the generated condition A determination unit that reads content identification information, and an instruction unit that transmits detailed metadata specified by the content identification information read by the determination unit to the multicast distribution device as the detailed metadata to be distributed by multicast And a metadata distribution system characterized by comprising That.

  The present invention is the above-described metadata distribution system, further comprising a content distribution device connected to the network, wherein the distribution request unit sends a content distribution request in which identification information of the content to be viewed is set to the content distribution The content distribution device is specified by the content identification information acquired from the detailed metadata distribution request after receiving the content distribution request from the terminal device and the content distribution device storage unit that stores the content data. A content distribution unit that reads and returns content data from the content distribution device storage unit; and a content distribution notification unit that notifies the determination device of identification information of the content to which the content distribution unit has returned content data. The record of the content related information table. And the update unit receives content identification information from the content distribution device and stores the content identification information in the content related information table corresponding to the content identification information. The content distribution number is updated, and the determination unit identifies a record in the content related information table in which the number of content data distributions is greater than or equal to a predetermined value, and multicasts detailed metadata based on the related information of the identified record. The condition for selecting a record of content to be transmitted is generated.

  Further, the present invention is the metadata distribution system described above, wherein the determination unit acquires related information that is commonly set at a predetermined ratio or more in the specified plurality of records, and the acquired relationship The condition is that information is set.

  Moreover, the present invention is the metadata distribution system described above, wherein the determination unit is based on the condition that related information having the same setting value as that of any one of the identified records is set. And

  Also, the present invention is the metadata distribution system described above, wherein the related information is any one of content genre, series, starring, director, supporting role, price, playback time, or two or more. .

Also, the present invention is the metadata distribution system described above, wherein the instruction unit uses the content identification information read by the determination unit as the identification information of the content to which detailed metadata should be distributed by multicast. Notify the multicast distribution device
The multicast distribution device receives identification information of content to which detailed metadata is to be distributed by multicast from the determination device, and identifies the received content among the detailed data stored in the multicast distribution device storage unit An instruction receiving unit for deleting detailed metadata other than the detailed metadata specified by the information;
It is characterized by that.

  In addition, the present invention provides summary metadata indicating an outline description of content, a multicast distribution apparatus that distributes detailed metadata indicating a detailed description of content by multicast, and a unicast distribution apparatus that distributes detailed metadata by unicast. And a metadata distribution system in which a determination device that selects content to which detailed metadata is to be transmitted by multicast and a terminal device of a user that displays the summary metadata and the detailed metadata are connected via a network A metadata distribution method, wherein the summary metadata includes content identification information and a summary description of the content, and the detailed metadata includes content identification information and a detailed description of the content, and the multicast The metadata distribution unit of the distribution device A metadata distribution step of distributing the summary metadata stored in the multicast distribution device storage unit and the detailed metadata to the terminal device by multicast; and a distribution data receiving unit of the terminal device, the multicast distribution device A distribution data receiving step for writing the summary metadata and the detailed metadata distributed from the terminal device to a terminal device storage unit included in the terminal device; and a summary metadata display control unit of the terminal device, the terminal device storage unit A summary metadata display step for displaying the summary metadata read from the summary metadata, and summary metadata selected by the user from the summary metadata displayed in the summary metadata display step by the distribution request unit of the terminal device Selected summary meta data When the detailed metadata in which the content identification information in the data is set is not stored in the terminal device storage unit, a detailed metadata distribution request in which the content identification information is set is transmitted to the unicast distribution device. A distribution request step, and a detailed metadata distribution unit of the unicast distribution device receives the detailed metadata distribution request from the terminal device, and the detailed metadata specified by the content identification information acquired from the detailed metadata distribution request A detailed metadata distribution step of reading data from a unicast distribution device storage unit provided therein and returning the data by unicast, and the distribution data reception unit of the terminal device is distributed from the unicast distribution device by unicast Detailed distribution metadata received to write detailed metadata to the terminal device storage unit And detailed metadata that the detailed metadata display control unit of the terminal device reads and displays the detailed metadata specified by the content identification information in the selected summary metadata from the terminal device storage unit A detailed metadata delivery notifying step in which the detailed metadata delivery notifying unit of the unicast delivery device notifies the determination device of the identification information of the content that has returned the detailed metadata in the detailed metadata delivery step; A storage unit that stores a content related information table including a plurality of records including content identification information, content related information, and the number of distributions of detailed metadata of the content by the unicast distribution device The update unit of the determination device receives a container from the unicast distribution device. The update step of updating the number of detailed metadata distribution in the content related information table corresponding to the identification information of the content, and the determination unit of the determination device, the number of distribution of the detailed metadata Specify a record in the content related information table that is equal to or greater than a predetermined value, and generate a record selection condition for selecting a record of content to which detailed metadata should be transmitted by multicast based on the related information of the specified record. A determination step of reading content identification information from another record including related information that matches the generated condition, and details specified by the content identification information read in the determination step by the instruction unit of the determination device Metadata as previous metadata to be distributed by multicast An instruction step of transmitting to the multicast distribution device; a metadata writing unit of the multicast distribution device receiving the detailed metadata to be distributed by multicast and writing to the multicast distribution device storage unit; A metadata distribution method characterized by comprising:

  According to the present invention, the summary metadata of all contents and the detailed metadata of contents expected to be in high demand are distributed to the terminal device by multicast from the multicast distribution apparatus, and the demand is not so high. The detailed metadata of the content is distributed by unicast by the unicast distribution device that has received the request from the terminal device. Therefore, it is possible to reduce the load that has been conventionally distributed in the metadata, and the memory load of the terminal device is not increased by the detailed metadata that is unlikely to be viewed. In addition, a lot of detailed metadata desired by the user can be immediately displayed on the terminal device.

It is a block diagram of the metadata delivery system by one embodiment of this invention. It is a block diagram which shows the function structure of the judgment apparatus by the embodiment. It is a block diagram which shows the function structure of the multicast delivery apparatus by the embodiment. It is a block diagram which shows the function structure of the unicast delivery apparatus by the embodiment. It is a block diagram which shows the function structure of the content delivery apparatus by the embodiment. It is a block diagram which shows the function structure of the terminal device by the same embodiment. It is a figure which shows the example of a data structure of the content relevant information table by the embodiment. It is a figure which shows the data structural example of the summary metadata by the embodiment. It is a figure which shows the data structural example of the detailed metadata by the embodiment. It is a figure which shows the screen transition displayed on the terminal device by the embodiment. It is a sequence diagram of metadata and content distribution processing in the metadata distribution system according to the embodiment. It is the delivery method decision processing flow of the judgment apparatus by the embodiment.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a metadata distribution system according to an embodiment of the present invention. In the figure, the metadata distribution system is assumed that the demand is not so high, and the multicast distribution device 2 that distributes the summary metadata of each content and the detailed metadata of the content that is expected to be in high demand by multicast. A unicast distribution device 3 that distributes detailed metadata of content to be distributed by unicast, a content distribution device 4 that distributes content data that is digital data of content, and a determination to select content for which detailed metadata is to be distributed by multicast A device 1 and a plurality of user terminal devices 5 are provided. The content to be distributed may be a program distributed by VoD (Video on Demand) or the like, or may be a program distributed by broadcasting.

  The determination device 1, the multicast distribution device 2, the unicast distribution device 3, and the content distribution device 4 are connected by a network 8 that is a private network of a content provider. The terminal device 5 is connected to the multicast distribution device 2, the unicast distribution device 3, and the content distribution device 4 through a network 9 such as the Internet.

  The summary metadata and the detailed metadata are used as an electronic content guide (ECG) and an electronic program guide (EPG). The summary metadata is data indicating a general description of the content, and the detailed metadata is data indicating a more detailed description of the content and related information than the description included in the summary metadata. These can be created based on metadata attached to the content data and describing information about the content (program).

  In this metadata distribution system, the detailed metadata of content that is expected to be in high demand is distributed from the multicast distribution device 2 to the terminal device 5 by multicast, and the detailed metadata of other content is requested from the terminal device 5. In response, the unicast distribution device 3 distributes the content by unicast, so that the load on the metadata distribution device for metadata distribution of popular content can be reduced. In addition, since only detailed metadata that is highly likely to be viewed by the user is distributed in advance to the terminal devices 5 of all users by multicast, the memory load of the terminal device 5 is increased by detailed metadata that is unlikely to be viewed. There is no end to it. In addition, it is possible to display a lot of detailed metadata desired by the user on the terminal device 5 immediately.

  FIG. 2 is a block diagram showing a functional configuration of the determination apparatus 1, and only functional blocks related to the present invention are extracted and shown. In the figure, the determination apparatus 1 includes a communication unit 11, a storage unit 12, and a processing unit 13, and can be realized by a server, for example. The communication unit 11 transmits and receives data via the network 8. The storage unit 12 stores a content-related information table in which information on each content is associated with the detailed metadata of each content and the number of distributions of the content data.

  The processing unit 13 includes an update unit 14, a determination unit 15, and an instruction unit 16. The update unit 14 receives the identification information of the content that has distributed the detailed metadata from the unicast distribution device 3 to the terminal device 5, and updates the number of distributions of the detailed metadata in the content related information table. In addition, the update unit 14 receives the identification information of the content distributed from the content distribution device 4 to the terminal device 5 and updates the number of distributions of the content data in the content related information table. The determination unit 15 refers to the content-related information table and selects content for which detailed metadata is to be distributed by multicast. The instructing unit 16 notifies the multicast distribution device 2 of identification information of content to which detailed metadata is to be distributed by multicast, and transmits the detailed metadata to the multicast distribution device 2.

  FIG. 3 is a block diagram showing a functional configuration of the multicast distribution apparatus 2, and only functional blocks related to the present invention are extracted and shown. In the figure, the multicast distribution device 2 includes a communication unit 21, a storage unit 22, and a processing unit 23, and can be realized by a server, for example. The communication unit 21 transmits and receives data via the networks 8 and 9. The storage unit 22 stores summary metadata of each content distributed by the content distribution device 4 and detailed metadata to be distributed by multicast.

  The processing unit 23 includes a metadata writing unit 24, a metadata distribution unit 25, and an instruction receiving unit 26. The metadata writing unit 24 writes the received summary metadata and detailed metadata to be distributed by multicast in the storage unit 22. The metadata distribution unit 25 reads the summary metadata and the detailed metadata from the storage unit 22 and instructs the communication unit 21 to perform multicast distribution via the network 9. For this multicast distribution, for example, an existing multicast distribution technique such as a FLUTE (File Delivery over Unidirectional Transport) protocol can be used. The instruction receiving unit 26 receives the identification information of the content to which the detailed metadata is to be distributed from the determination device 1 by multicast, and when the detailed metadata specified by the identification information of the content is not stored in the storage unit 22 , Request the detailed metadata.

  FIG. 4 is a block diagram showing a functional configuration of the unicast distribution apparatus 3, and only functional blocks related to the present invention are extracted and shown. In the figure, the unicast distribution apparatus 3 includes a communication unit 31, a storage unit 32, and a processing unit 33, and can be realized by a server, for example. The communication unit 31 transmits and receives data via the networks 8 and 9. The storage unit 32 stores detailed metadata.

  The processing unit 33 includes a detailed metadata writing unit 34, a detailed metadata distribution unit 35, and a detailed metadata distribution notification unit 36. The detailed metadata writing unit 34 writes the received detailed metadata in the storage unit 32. When the detailed metadata distribution unit 35 receives a unicast detailed metadata distribution request from the terminal device 5 via the communication unit 31, the detailed metadata distribution unit 35 reads the requested detailed metadata from the storage unit 32, and The communication unit 31 is instructed to return to the terminal device 5 by unicast. For this unicast distribution, for example, an existing unicast distribution technique such as an HTTP (Hypertext Transfer Protocol) protocol can be used. The detailed metadata delivery notifying unit 36 notifies the determination device 1 of the identification information of the content that delivered the detailed metadata to the terminal device 5.

  FIG. 5 is a block diagram showing a functional configuration of the content distribution apparatus 4, and only functional blocks related to the present invention are extracted and shown. In the figure, the content distribution apparatus 4 includes a communication unit 41, a storage unit 42, and a processing unit 43, and can be realized by a server, for example. The communication unit 41 transmits and receives data via the networks 8 and 9. The storage unit 42 stores content data of each content.

  The processing unit 43 includes a writing unit 44, a content distribution unit 45, and a content distribution notification unit 46. The writing unit 44 writes the received content data into the storage unit 42. The content distribution unit 45 receives the content distribution request from the terminal device 5, reads out the content data of the requested content from the storage unit 42, and returns it. The content distribution notification unit 46 notifies the determination device 1 of identification information of the content that has distributed the content data to the terminal device 5.

  FIG. 6 is a block diagram showing a functional configuration of the terminal device 5, and only functional blocks related to the present invention are extracted and shown. In the figure, a terminal device 5 includes a communication unit 51, a storage unit 52, an input unit 53, an output unit 54, and a processing unit 55, and is realized by, for example, a television receiver, a personal computer, a mobile phone terminal, or the like. be able to. The communication unit 51 transmits and receives data via the network 9. The storage unit 52 stores data such as summary metadata, detailed metadata, and content data. The input unit 53 is, for example, a remote controller, a button, a keyboard, and the like, and is a device for inputting a user operation. The output unit 54 is a display that displays video, a speaker that outputs audio, and the like.

  The processing unit 55 includes a distribution data receiving unit 56, an output control unit 57, and a distribution request unit 58. The distribution data receiving unit 56 writes the summary metadata, detailed metadata, and content data received by the communication unit 51 in the storage unit 52. The output control unit 57 instructs the output unit 54 to output the summary metadata, detailed metadata, and content data read from the storage unit 52. The distribution request unit 58 instructs the communication unit 51 to transmit a distribution request for detailed metadata and content data.

  Note that any of the multicast distribution device 2, the unicast distribution device 3, and the content distribution device 4 may have the function of the determination device 1. For example, the determination device 1 may be realized by the same server as any one of the multicast distribution device 2, the unicast distribution device 3, and the content distribution device 4.

  FIG. 7 is a diagram illustrating a data configuration example of the content related information table stored in the storage unit 12 of the determination apparatus 1. In the figure, the content related information table includes a content ID that is an identifier for uniquely identifying the content, a genre to which the content belongs, a person related to the content, a content title and series, a content playback time, a content price, and related content. Content ID, the number of requests for detailed metadata, the number of content distributions, and the like. For example, comedy, action, documentary, etc. are set in the genre, and in the item of the person, the leading role, the supporting role, the director (director) of the content (program) (hereinafter referred to as “director” collectively) Name) is set. In addition, when a program consists of a series of series such as 1st to 10th, the same series name is described in the series item for the contents belonging to the series.

FIG. 8 is a diagram illustrating a data configuration example of the summary metadata.
The summary metadata includes information such as a content ID, a content title, a genre, and a summary description of the content, and is described in, for example, XML (extensible markup language). The summary description includes a short and simple description of the content such as a synopsis of the content and advertisement.

FIG. 9 is a diagram illustrating a data configuration example of detailed metadata.
The detailed metadata includes information such as content ID, content person, content playback time, price, series, and detailed description, and content preview image data. For example, information other than content preview image data is expressed in XML. Described. In the detailed description, for example, it is possible to describe an arbitrary content longer than the outline description, such as a description of the work, information on the photographed local area, and related content to be released in the future.

FIG. 10 is a diagram illustrating screen transitions displayed on the display of the terminal device 5.
When a content list display instruction is input by the input unit 53 of the terminal device 5, the content list display screen G1 is displayed on the display. On the content list display screen G1, a genre selection button, a title and summary description of each content, and a detailed display button B1 corresponding to each content are displayed.

  When the user selects the detail display button B1 of the desired content using the input unit 53 of the terminal device 5 and inputs a decision, a detail display screen G2 is displayed on the display. The detail display screen G2 displays the genre of the selected content, the performer, the person related to the content such as the director, the content playback time, the price, the series, the detailed description, the preview image, and the viewing button B2. When the user inputs the determination of the viewing button B <b> 2 through the input unit 53 of the terminal device 5, the content data is distributed from the content distribution device 4. The terminal device 5 reproduces the distributed content data, displays the content image on the display, and outputs sound from the speaker.

Next, the operation of the metadata distribution system according to this embodiment will be described.
FIG. 11 is a sequence diagram of metadata and content distribution processing in the metadata distribution system according to the present embodiment.
First, the content distribution provider writes outline metadata of newly distributed content in the multicast distribution device 2, detailed metadata of the content in the unicast distribution device 3, and content data of the content in the content distribution device 4. . This is performed, for example, by uploading summary metadata, detailed metadata, and content data to the multicast delivery device 2, the unicast delivery device 3, and the content delivery device 4 from the determination device 1 of the content delivery company. The metadata writing unit 24 of the multicast distribution device 2 writes the summary metadata received from the determination device 1 to the storage unit 22, and the detailed metadata writing unit 34 of the unicast distribution device 3 receives the determination metadata from the determination device 1. The detailed metadata is written in the storage unit 32, and the writing unit 44 of the content distribution device 4 writes the content data received from the determination device 1 in the storage unit 42. Note that detailed metadata that is expected to be in high demand in advance may be uploaded to the multicast distribution device 2. Further, the content provider registers a record corresponding to the content in the content related information table stored in the storage unit 12 of the determination device 1. However, the number of detailed metadata distributions and the number of content distributions are set to initial values 0.

  When the metadata distribution unit 25 of the multicast distribution device 2 reads the summary metadata and the detailed metadata stored in the storage unit 22 at a predetermined time, the metadata distribution unit 25 multicasts the summary metadata and the detailed metadata to the communication unit 21. To instruct delivery. All the terminal devices 5 receive the summary metadata and the detailed metadata transmitted from the multicast distribution device 2 (step S110).

  When the communication unit 51 of the terminal device 5 receives the summary metadata and the detailed metadata transmitted from the multicast distribution device 2 via the network 8, the distribution data receiving unit 56 receives the received summary metadata and detailed metadata. Write to the storage unit 52 (step S120). The distribution of the summary metadata and the detailed metadata may be performed periodically such as once a week, once or several times a day, and when the content distribution company inputs an instruction to the multicast distribution device 2. It may be. Here, it is assumed that the summary metadata of the contents C1 to Cn and the detailed metadata of the contents C5 having the content IDs 0001 to n are distributed from the multicast distribution device 2.

  The user inputs a content list display instruction via the input unit 53 of the terminal device 5 (step S130). As a result, the output control unit 57 displays a list of genres on the display. When the user inputs the genre selected by the input unit 53, the output control unit 57 reads the summary metadata in which the input genre is set from the storage unit 52, and reads the title read from each of the read summary metadata, A summary description list is displayed on the display by the content list display screen G1 (step S140). Here, it is assumed that the title and outline description read from the outline metadata of the contents C1, C2, C5,... In which the input genre “action” is set are displayed. Note that information read from all summary metadata stored in the storage unit 52 may be displayed on the content list display screen G1 without specifying the genre.

  When the user browses the information displayed on the content list display screen G1 and selects a content for which more detailed information is to be viewed, the user selects the content detail display button B1 corresponding to the selected content on the input unit of the terminal device 5. 53 is selected (step S150). Here, it is assumed that the detail display button B1 corresponding to the content C1 is selected. When the output control unit 57 acquires the content ID “0001” from the summary metadata corresponding to the selected content C1, the output control unit 57 determines whether the detailed metadata in which the content ID is set is stored in the storage unit 52. (Step S160). Since the detailed metadata of the content C1 is not stored in the storage unit 52 (step S160: NO), the distribution request unit 58 transmits the detailed metadata distribution request in which the content ID is set to the unicast distribution apparatus 3. An instruction is given to the communication unit 21 (step S170).

  The detailed metadata distribution unit 35 of the unicast distribution device 3 receives the detailed metadata distribution request transmitted by unicast from the terminal device 5 via the communication unit 31 (step S180). When the detailed metadata distribution unit 35 acquires the content ID from the received detailed metadata distribution request and reads the detailed metadata in which the acquired content ID is set from the storage unit 32, the detailed metadata distribution unit 35 reads the detailed metadata of the read content C1. The communication unit 31 is instructed to return data. The communication unit 31 transmits the detailed metadata read by the detailed metadata distribution unit 35 to the terminal device 5 that has requested the detailed metadata distribution by unicast (step S190). Further, the detailed metadata distribution unit 35 stores detailed metadata distribution history information in which the content ID of the content C1 acquired from the detailed metadata distribution request is associated with the detailed metadata distribution date and time indicating the current date and time. (Step S200).

  When receiving the detailed metadata of the content C1 from the unicast distribution device 3 via the communication unit 51, the distribution data receiving unit 56 of the terminal device 5 writes the detailed metadata into the storage unit 52 (step S210). The output control unit 57 displays the performer, content playback time, price, series, detailed description, and preview image of the content C1 acquired from the detailed metadata written in the storage unit 52 by the distribution data receiving unit 56 in a detailed display screen. It is displayed on the display by G2 (step S220). In addition, information acquired from the outline metadata of the content C1, such as a genre and a title, can be displayed on the detailed display screen G2.

  When the user browses the information displayed on the detailed display screen G2 and decides to view the content C1, the user inputs the decision of the viewing button B2 through the input unit 53 of the terminal device 5 (step S230). The distribution request unit 58 instructs the communication unit 51 to transmit a content distribution request in which the content ID of the content C1 is set to the content distribution device 4 (step S240).

  The content distribution unit 45 of the content distribution device 4 receives a content distribution request from the terminal device 5 via the communication unit 41 (step S250). The content distribution unit 45 acquires the content ID “0001” from the received content distribution request. When the content distribution unit 45 reads the content data specified by the acquired content ID from the storage unit 42, the content distribution unit 45 instructs the communication unit 41 to return the read content data. The communication unit 41 transmits the content data read by the content distribution unit 45 to the terminal device 5 that is the content distribution request source (step S260). Furthermore, the content distribution unit 45 stores content distribution history information in which the content ID of the content C1 acquired from the content distribution request is associated with the content distribution date and time indicating the current date and time in the storage unit 42 (step S270).

  When receiving the content data of the content C1 from the content distribution device 4 via the communication unit 51, the distribution data receiving unit 56 of the terminal device 5 writes the content data in the storage unit 52 (step S280). The output control unit 57 reproduces the content data written to the storage unit 52 by the distribution data receiving unit 56 and causes the output unit 54 to output the content data (step S290). The user enjoys the content C1 by using an image displayed on the display of the terminal device 5 or sound output from a speaker. In the case of downloading, all received content data is stored in the storage unit 52 and then reproduced. On the other hand, in the case of streaming reproduction, reproduction is performed while the received content data is stored in the storage unit 52, but the portion of the content data that has been reproduced may be deleted from the storage unit 52.

  When the user browses the information displayed on the content list display screen G1 and selects the detail display button B1 corresponding to the content C5 by the input unit 53 of the terminal device 5, the output control unit 57 selects The content ID is acquired from the summary metadata corresponding to the content C5, and it is determined whether the detailed metadata in which the content ID is set is stored in the storage unit 52 (step S160). Since the detailed metadata of the content C5 is stored in the storage unit 52 (step S160: YES), the output control unit 57 reads the detailed metadata of the content C5 from the storage unit 52 and acquired from the detailed metadata. The performer of content C5, content playback time, price, series, detailed description, preview image, and genre acquired from the summary metadata of content C5 are displayed on the display by the detailed display screen G2 (step S220).

  The processing after the user browses the detailed information of the content C5 and inputs the determination of the viewing button B2 in the detailed display screen G2 by the input unit 53 of the terminal device 5 is the same as described above. That is, the terminal device 5 transmits a content distribution request in which the content ID of the content C5 is set to the content distribution device 4, and the content distribution device 4 returns the content data of the content C5 requested by the content distribution request. The content distribution history information in which the content ID of the content C5 is associated with the content distribution date and time indicating the current date and time is stored in the storage unit. When the terminal device 5 receives the content data of the content C5 from the content distribution device 4, the terminal device 5 writes the content data into the storage unit 52 and reproduces it, and outputs the content C5 by the output unit 54.

  If the preview image data is not included in the detailed metadata, the terminal device 5 transmits the content ID to a preview image distribution device (not shown) that stores the preview image data of each content immediately before step S220. The preview image data corresponding to the transmitted content ID is received from the preview image distribution device and displayed on the detail display screen G2. Alternatively, the URL (Universal Resource Locator) of the preview image may be described in the detailed metadata, and the terminal device 5 may acquire the preview image from the site specified by this URL.

The detailed metadata distribution notification unit 36 of the unicast distribution device 3 has a detailed metadata distribution history in which the detailed metadata distribution date and time is the date and time after the previous notification to the determination device 1 every predetermined time such as once a day. Information is read out and notified to the determination apparatus 1 (step S300).
Similarly, the content distribution notification unit 46 of the content distribution device 4 reads content distribution history information whose content distribution date and time is after the date and time when the notification to the determination device 1 was made last time at predetermined time intervals such as once a day. The determination device 1 is notified (step S310).
The update unit 14 of the determination device 1 writes the detailed metadata distribution history information received from the unicast distribution device 3 and the content distribution history information received from the content distribution device 4 in the storage unit 12 (step S320).

  Note that the unicast distribution device 3 and the content distribution device 4 may notify the determination device 1 of the information in which the detailed metadata and the content ID of the content that has distributed the content data are associated with the distribution date and time. Good.

FIG. 12 is a diagram illustrating a distribution method determination processing flow by the determination apparatus 1.
The update unit 14 of the determination device 1 writes the detailed metadata distribution history information received from the unicast distribution device 3 and the content distribution history information received from the content distribution device 4 in the storage unit 12 (step S410). The update unit 14 specifies the detailed metadata distribution history information whose detailed metadata distribution date and time is within a predetermined period from the present, for example, within one month, among the detailed metadata distribution history information stored in the storage unit 12. . The update unit 14 acquires the number of detailed metadata distributions corresponding to each content ID by measuring the number of each content ID set in the specified detailed metadata distribution history information. The updating unit 14 updates the detailed metadata distribution number of each content ID set in the content related information table in the storage unit 12 with the acquired detailed metadata distribution number of the content ID (step S420).

  Furthermore, the update unit 14 specifies content distribution history information whose content distribution date and time is within a predetermined period from the present, for example, within one month, among the content distribution history information stored in the storage unit 12. The update unit 14 acquires the number of content distributions corresponding to each content ID by measuring the number of content IDs set in the specified content distribution history information. The updating unit 14 updates the content distribution number of each content set in the content related information table in the storage unit 12 with the acquired content distribution number of the content ID (step S430).

  When the number of detailed metadata distributions and the number of content distributions in the content-related information table are updated, the determination unit 15 of the determination device 1 records the content to which detailed metadata should be transmitted by multicast based on the record with the large number of distributions. The condition for selecting is determined, and the content ID is read from the record that matches the condition. As a result, the content for which the detailed metadata is to be transmitted by multicast is selected. Specifically, this is performed as follows.

  First, the determination unit 15 identifies records whose detailed metadata distribution number is greater than or equal to a predetermined threshold, for example, 150,000 or more, and acquires the number of the identified records among the records registered in the content related information table. (Step S440). The determination unit 15 obtains a set value and a set ratio that are set in common for each item of the series, main role, director, supporting role, content playback time, and price of the record identified in step S440. Then, a setting value with a setting ratio equal to or higher than a predetermined threshold value is selected (step S450). Note that the threshold value may be changed for each item. The determination unit 15 reads the content IDs of all the records in which the selected setting value is set from the content related information table, and uses the read content IDs as the content IDs of the contents to which detailed metadata should be distributed by multicast. (Step S460).

  For example, among the plurality of records identified in step S440, the ratio in which “Mr. A” is set as the leading role is 30%, the ratio in which “Mr. D” is set is 20%, and the threshold is 15 %. The determination unit 15 reads the content IDs = 0001, 0002, 0003,... Of the record in which “Mr. A” or “Mr. D” is set as the main character of the person from the content-related information table, and uses the detailed meta data by multicast. The content ID of the content to which data is to be distributed is used. Similar processing is performed for each of the other items.

  Subsequently, the determination unit 15 uses a combination of common setting values and a setting ratio for all combinations of the genre, series, leading role, director, supporting role, content playback time, and price items specified in step S440. And a combination of setting values whose setting ratio exceeds a predetermined threshold value is selected (step S470). Note that the threshold value may be changed for each combination of items. The determination unit 15 reads the content ID of the record in which the combination of the selected setting values is set from the content related information table, and sets the read content ID as the content ID of the content to which detailed metadata is to be distributed by multicast. The detailed metadata read in step S460 is added to the content ID of the content to be distributed (step S480).

  For example, in the combination of the items of genre, director, and content playback time in the record identified in step S440, the ratio of the genre “action”, the director “B”, and the price “150 yen” is 12%. It is assumed that the threshold value exceeds 10%. The determination unit 15 reads the content ID = 0002, 0005,... Of the record in which the combination of the genre “action”, the director “Mr. B”, and the price “150 yen” is set from the content related information table, and multicasts it. The detailed metadata is the content ID of the content to be distributed.

  Next, the determination unit 15 identifies a record whose content distribution number is equal to or greater than a predetermined threshold among the records registered in the content related information table, and acquires the number of the identified record (step S490). This threshold is determined by how much the content distribution number is weighted more than the detailed metadata distribution number. For example, when the number of content distributions is weighted 1.5 times the number of detailed metadata distributions, the threshold value is 150,000 / 1.5 = 100,000.

  Hereinafter, the determination unit 15 obtains the content ID of the content for which the detailed metadata is to be transmitted by multicast for the record specified in step S490 by the same process as in steps S450 to S480 (steps S500 to S530). That is, the determination unit 15 sets a common setting value for each of the items of the series, the leading role, the director, the supporting role, the content playback time, and the price of the plurality of records identified in step S490, A setting ratio is acquired, and a setting value with a setting ratio equal to or greater than a predetermined threshold is selected (step S500). The determination unit 15 reads the content IDs of all the records in which the selected setting value is set from the content related information table, and sets the read content IDs as the content IDs of the contents to which the detailed metadata should be distributed by multicast. The detailed metadata read in steps S460 and S480 is added to the content ID of the content to be distributed (step S510).

  Subsequently, the determination unit 15 acquires a common combination of setting values and setting ratios for all combinations of the genre, series, leading role, director, supporting role, content playback time, and price item specified in step S490. Then, a combination of setting values whose setting ratio exceeds a predetermined threshold value is selected (step S520). The determination unit 15 reads the content ID of the record in which the combination of the selected setting values is set from the content related information table, and sets the read content ID as the content ID of the content to which detailed metadata is to be distributed by multicast. The detailed metadata read in step S460, step S480, and step S510 is added to the content ID of the content to be distributed (step S530).

The determination unit 15 selects the related content from the record selected as the detailed metadata distribution number being the predetermined threshold value in step S440 and the record selected as the content distribution number is the predetermined threshold value or more in step S490. The content ID is read out, and the read content ID is set as the content ID of the content to which the detailed metadata is to be distributed by multicast, and the content metadata read out in step S460, step S480, step S510, and step S530 is read. It adds to content ID (step S540). Note that the content ID of the related content should be read from the record of the content related information table specified by the content ID acquired in steps S460, S480, S510, and S530, and the detailed metadata should be distributed by multicast using the read content ID. The detailed metadata read in step S460, step S480, step S510, and step S530 may be added to the content ID of the content to be distributed as the content ID of the content.
The instructing unit 16 transmits the content ID of the content for which detailed metadata is to be transmitted by multicast, read in steps S460, S480, S510, S530, and S540, to the multicast distribution device 2 (step S550).

  The instruction receiving unit 26 of the multicast distribution device 2 determines whether the detailed metadata in which the content ID received from the determination device 1 is set is stored in the storage unit 22. If there is a content ID for which detailed metadata is not registered, a detailed metadata acquisition request in which the content ID is set is transmitted to the determination apparatus 1.

  When receiving the detailed metadata acquisition request from the multicast distribution device 2 (step S560: YES), the instruction unit 16 of the determination device 1 stores detailed metadata corresponding to the content ID set in the detailed metadata acquisition request. 12 is acquired from the unicast distribution device 3 and returned to the multicast distribution device 2 (step S570). The metadata writing unit 24 of the multicast distribution device 2 writes the received detailed metadata in the storage unit 22.

  Further, the instruction receiving unit 26 of the multicast distribution device 2 sets the detailed metadata in which the content ID not included in the content ID received from the determination device 1 among the detailed metadata currently stored in the storage unit 22 is set. And the specified detailed metadata is deleted from the storage unit 22. This may be erased from the memory or logically deleted. In the case of logical deletion, information indicating that it is not targeted for multicast distribution is stored in the storage unit 22 in association with the detailed metadata. When the metadata distribution unit 25 of the multicast distribution device 2 distributes the detailed metadata in the storage unit 22, only the information that is not associated with the multicast distribution target is distributed. .

  In step S550, the instruction unit 16 of the determination device 1 transmits the detailed metadata specified by the content ID to the multicast distribution device 2 together with the content ID of the content to which the detailed metadata is to be transmitted by multicast. You may do it.

  Thereafter, the determination device 1 can distribute the detailed metadata that is highly likely to be viewed by the user from the multicast distribution device 2 by multicast. In addition, it is possible to return from the multicast distribution to the unicast distribution for the detailed metadata of the contents whose popularity has decreased. In addition, since the condition of the content that is expected to be popular is obtained from the analysis result in the determination apparatus 1, the detailed metadata that meets the condition is uploaded to the multicast distribution apparatus 2 from the beginning and distributed by multicast. You can also.

  Note that in steps S470 and S520 described above, combinations of common setting values that exceed the threshold are selected for all combinations using the items of genre, leading role, director, supporting role, content playback time, and price. However, it is also possible to determine a combination of items in advance (for example, a combination of a genre and an actor) and select a combination of common setting values that exceeds the threshold among the determined combinations of items.

  In addition, the determination unit 15 of the determination device 1 may acquire the following (1) to (6) as the content ID of the content to which detailed metadata should be transmitted by multicast.

(1) The determination unit 15 of the determination apparatus 1 identifies a record whose detailed metadata distribution number or content distribution number is equal to or greater than a predetermined threshold among the records registered in the content related information table. Then, the determination unit 15 reads the content ID from the record in the content-related information table in which the set value that is the same as the series, the leading role, or the director of the specified record is set to the series, the leading role, or the director. The content ID of content to be distributed in detail by multicast is used.

  For example, it is assumed that the series “action great operation”, the leading role “Mr. A”, and the director “Mr. B” are set in a record whose detailed metadata distribution number is equal to or greater than a threshold. In this case, from the content-related information table, all records for which “Action Great Operation” is set for the series, all records for which the main character “Mr. A” is set, and all for which the director “Mr. B” is set The content ID acquired from these specified records is set as the content ID of the content to which the detailed metadata is to be distributed by multicast.

(2) The determination unit 15 of the determination apparatus 1 identifies a record whose detailed metadata distribution number or content distribution number is equal to or greater than a predetermined threshold among the records registered in the content related information table. Then, the determination unit 15 should read the content ID from the record in the content related information table in which the same set value as the combination of the predetermined items of the specified record is set, and distribute the detailed metadata by multicast The content ID of the content is used.

For example, it is assumed that a combination of predetermined items is a leading role and a supporting role, and a leading role “Mr. A” and a supporting role “Mr. C” are set in a record whose detailed metadata distribution number is equal to or greater than a threshold. In this case, all the records in which the combination of the main character “Mr. A” and the supporting character “Mr. C” is set in the series are identified from the content related information table, and the content ID acquired from the identified record is multicast. The detailed metadata is the content ID of the content to be distributed.
Examples of combinations of items include any combination of the leading role, director, supporting role, one or more of the leading role, director, and price and a combination of genre or series, a combination of each of these combinations and content playback time, etc. is there.

(3) The determination unit 15 of the determination device 1 identifies a record whose detailed metadata distribution number or content distribution number is equal to or greater than a predetermined threshold among the records registered in the content related information table. Then, the determination unit 15 reads the content ID from the record in the content-related information table in which the same setting value as the main role, director, or supporting role of the identified record is set to the leading role, director, or supporting role, This is the content ID of the content for which detailed metadata is to be distributed by multicast.

  For example, it is assumed that the leading role “Mr. A”, the director “Mr. B”, and the supporting role “Mr. C” are set in a record whose detailed metadata distribution number is equal to or greater than the threshold. In this case, all the records in which “Mr. A”, “Mr. B” or “Mr. C” is set to any of the leading role, director, and supporting role are identified from the content-related information table, and from these identified records The acquired content ID is set as the content ID of the content for which detailed metadata is to be distributed by multicast.

(4) The determination unit 15 of the determination device 1 is a record in which the total of the number of detailed metadata distributions and the weighted content distribution number is greater than or equal to a predetermined threshold among the records registered in the content related information table Is identified. For example, when the weight of the number of content distributions is 1.5 times the number of detailed metadata distributions, a record in which (detailed metadata distribution number) + 1.5 × (content distribution number) is equal to or greater than a threshold value is specified. Then, the same processing as steps S450 to S480 or the above (1) to (3) is performed on the specified record, and the content ID of the content to which the detailed metadata is to be distributed is acquired.

(5) The determination device 1 receives a word that is currently input as a search keyword from a search device (not shown) provided with a search engine provided on the Internet or the like. Then, the determination unit 15 of the determination apparatus 1 reads the content ID from the record of the content related information table in which the word is set to the title, series, or person name, and sets this as the content ID to be transmitted by multicast. .

(6) In the judgment device 1, the setting value of an item such as a title, a leading role, a director, a supporting role, or a series that is expected to be popular from the situation of a work, a talent, a director, or the like that is currently on the topic, or arbitrary Enter the combination of items and the settings for those items. The determination unit 15 of the determination apparatus 1 should read the content ID from the record of the content related information table in which the set value of the input item or the combination of the set values of a plurality of items is set, and transmit this by multicast Let it be a content ID.

  The determination device 1, the multicast distribution device 2, the unicast distribution device 3, the content distribution device 4, and the terminal device 5 have a computer system therein. The processing unit 13 of the determination device 1, the processing unit 23 of the multicast distribution device 2, the processing unit 33 of the unicast distribution device 3, the processing unit 43 of the content distribution device 4, and the processing unit 55 of the terminal device 5. The process is stored in a computer-readable recording medium in the form of a program, and the above processing is performed by the computer system reading and executing this program. The computer system here includes a CPU, various memories, an OS, and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the present invention, and it goes without saying that these are also included in the scope of the present invention. Yes.

DESCRIPTION OF SYMBOLS 1 ... Judgment apparatus 11 ... Communication part 12 ... Memory | storage part 13 ... Processing part 14 ... Update part 15 ... Judgment part 16 ... Instruction part 2 ... Multicast delivery apparatus 21 ... Communication part 22 ... Memory | storage part (multicast delivery apparatus memory | storage part)
DESCRIPTION OF SYMBOLS 23 ... Processing part 24 ... Metadata writing part 25 ... Metadata delivery part 26 ... Instruction receiving part 3 ... Unicast delivery apparatus 31 ... Communication part 32 ... Storage part (unicast delivery apparatus storage part)
DESCRIPTION OF SYMBOLS 33 ... Processing part 34 ... Detailed metadata writing part 35 ... Detailed metadata delivery part 36 ... Detailed metadata delivery notification part 4 ... Content delivery apparatus 41 ... Communication part 42 ... Memory | storage part 43 ... Processing part 44 ... Writing part 45 ... Content distribution unit 46 ... Content distribution notification unit 5 ... Terminal device 51 ... Communication unit (terminal device storage unit)
52 ... Storage unit 53 ... Input unit 54 ... Output unit 55 ... Processing unit 56 ... Distribution data receiving unit 57 ... Output control unit (outline metadata display control unit, detailed metadata display control unit)
58 ... Distribution request part 8, 9 ... Network

Claims (7)

Multicast distribution apparatus that distributes summary metadata indicating outline description of content and detailed metadata indicating detail description of content by multicast, unicast distribution apparatus that distributes detailed metadata by unicast, and detailed metadata by multicast A metadata distribution system in which a determination device for selecting content to be transmitted and a user terminal device that displays the summary metadata and the detailed metadata are connected via a network,
The summary metadata includes content identification information and a summary description of the content,
The detailed metadata includes content identification information and a detailed description of the content,
The multicast distribution device is:
A multicast delivery device storage unit for storing the summary metadata and the detailed metadata;
The summary metadata stored in the multicast delivery device storage unit, and the metadata delivery unit for delivering the detailed metadata to the terminal device by multicast;
A metadata writing unit that receives the detailed metadata to be distributed by multicast and writes the detailed metadata to the multicast distribution device storage unit;
The terminal device
A terminal device storage unit for storing the summary metadata and the detailed metadata;
The summary metadata and the detailed metadata distributed by multicast from the multicast distribution device are written in the terminal device storage unit, and the detailed metadata distributed by unicast from the unicast distribution device is stored in the terminal device storage A distribution data receiving unit for writing to the unit;
A summary metadata display control unit for displaying the summary metadata read from the terminal device storage unit;
Detailed metadata in which identification metadata of content in the selected summary metadata is set in response to input of summary metadata selected by the user from the summary metadata displayed by the summary metadata display control unit. A distribution request unit that, when not stored in the terminal device storage unit, transmits a detailed metadata distribution request in which identification information of the content is set to the unicast distribution device;
A detailed metadata display control unit that reads out and displays the detailed metadata specified by the content identification information in the selected summary metadata from the terminal device storage unit;
With
The unicast delivery device
A unicast distribution device storage unit for storing the detailed metadata;
Details of receiving the detailed metadata distribution request from the terminal device, reading out the detailed metadata specified by the content identification information acquired from the detailed metadata distribution request from the unicast distribution device storage unit and returning it by unicast A metadata distribution department;
A detailed metadata delivery notification unit for notifying the determination device of identification information of the content to which the detailed metadata delivery unit has returned the detailed metadata;
With
The determination device includes:
A storage unit for storing a content related information table including a plurality of records including content identification information, related information of the content, and the number of distributions of the detailed metadata of the content by the unicast distribution device;
An update unit that receives content identification information from the unicast distribution device and updates the number of detailed metadata distributions in the content related information table corresponding to the content identification information;
For identifying a record in the content related information table in which the number of distributions of detailed metadata is greater than or equal to a predetermined number, and selecting a record of content to which detailed metadata should be transmitted by multicast based on the related information of the identified record A determination unit that generates a condition and reads content identification information from other records including related information that matches the generated condition;
An instruction unit that transmits detailed metadata specified by the identification information of the content read by the determination unit to the multicast distribution device as the detailed metadata to be distributed by multicast;
Comprising
A metadata distribution system characterized by that. A content delivery device connected to the network;
The distribution request unit transmits a content distribution request in which identification information of content to be viewed is set to the content distribution device,
The content distribution device includes:
A content distribution device storage unit for storing content data;
A content distribution unit that receives a content distribution request from the terminal device, reads content data specified by the content identification information acquired from the detailed metadata distribution request from the content distribution device storage unit, and returns the content data;
A content delivery notification unit for notifying the determination device of identification information of the content to which the content delivery unit has returned content data;
With
The record of the content related information table further includes the number of content data distributed by the content distribution device,
The update unit receives content identification information from the content distribution device, updates the number of content distributions in the content related information table corresponding to the content identification information,
The determination unit identifies a record in the content related information table in which the number of distributions of content data is greater than or equal to a predetermined value, and selects a content record to which detailed metadata should be transmitted by multicast based on the related information of the identified record Generating the condition to
The metadata distribution system according to claim 1. The determination unit acquires related information that is commonly set in a predetermined ratio or more in the specified plurality of records, and the condition is that the acquired related information is set.
The metadata distribution system according to claim 1, wherein the metadata distribution system is a metadata distribution system. The determination unit is based on the condition that related information of the same setting value as that of any one of the specified records is set.
The metadata distribution system according to claim 1, wherein the metadata distribution system is a metadata distribution system.   5. The metadata distribution system according to claim 3, wherein the related information is any one or more of a content genre, a series, a starring, a director, a supporting role, a price, and a reproduction time. The instruction unit notifies the multicast distribution device of content identification information read by the determination unit as content identification information to which detailed metadata should be distributed by multicast,
The multicast distribution device receives identification information of content to which detailed metadata is to be distributed by multicast from the determination device, and identifies the received content among the detailed data stored in the multicast distribution device storage unit An instruction receiving unit for deleting detailed metadata other than the detailed metadata specified by the information;
The metadata delivery system according to any one of claims 1 to 5, wherein Multicast distribution apparatus that distributes summary metadata indicating outline description of content and detailed metadata indicating detail description of content by multicast, unicast distribution apparatus that distributes detailed metadata by unicast, and detailed metadata by multicast A metadata distribution method in a metadata distribution system in which a determination device that selects content to be transmitted and a user terminal device that displays the summary metadata and the detailed metadata are connected via a network. And
The summary metadata includes content identification information and a summary description of the content,
The detailed metadata includes content identification information and a detailed description of the content,
A metadata distribution step in which the metadata distribution unit of the multicast distribution device distributes the summary metadata stored in the multicast distribution device storage unit and the detailed metadata to the terminal device by multicast;
A distribution data receiving step in which a distribution data receiving unit of the terminal device writes the summary metadata and the detailed metadata distributed by multicast from the multicast distribution device to a terminal device storage unit of the terminal device;
A summary metadata display step of causing the summary metadata display control unit of the terminal device to display the summary metadata read from the terminal device storage unit;
The distribution request unit of the terminal device receives the input of the summary metadata selected by the user from the summary metadata displayed in the summary metadata display step, and the identification information of the content in the selected summary metadata When the detailed metadata set is not stored in the terminal device storage unit, a distribution request step for transmitting a detailed metadata distribution request in which the identification information of the content is set to the unicast distribution device;
The detailed metadata distribution unit of the unicast distribution device receives the detailed metadata distribution request from the terminal device and includes the detailed metadata specified by the content identification information acquired from the detailed metadata distribution request. A detailed metadata delivery step of reading from the unicast delivery device storage and returning by unicast;
A delivery detail metadata receiving step in which the delivery data receiving unit of the terminal device writes the detailed metadata delivered by unicast from the unicast delivery device to the terminal device storage unit;
Detailed metadata display control step of causing the detailed metadata display control unit of the terminal device to read out and display the detailed metadata specified by the content identification information in the selected summary metadata from the terminal device storage unit When,
A detailed metadata distribution notification unit of the unicast distribution device, which notifies the determination device of identification information of the content that has returned detailed metadata in the detailed metadata distribution step;
The determination including a storage unit that stores a content related information table including a plurality of records including content identification information, content related information, and the number of distributions of detailed metadata of the content by the unicast distribution device. An update step in which an update unit of the apparatus receives content identification information from the unicast distribution apparatus and updates the number of detailed metadata distributions in the content related information table corresponding to the content identification information;
The determination unit of the determination device should specify a record in the content related information table in which the number of distributions of detailed metadata is greater than or equal to a predetermined number, and transmit the detailed metadata by multicast based on the related information of the specified record A determination step of generating a condition for selecting a record of the content and reading the identification information of the content from other records including the related information that matches the generated condition;
An instruction step in which the instruction unit of the determination device transmits detailed metadata specified by the content identification information read in the determination step to the multicast distribution device as the detailed metadata to be distributed by multicast;
A metadata writing unit of the multicast distribution device that receives the detailed metadata to be distributed by multicast and writes the metadata to the multicast distribution device storage unit;
A metadata distribution method characterized by comprising:

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