JP2015095824A - Content distribution system, p2p terminal, viewing start assistance server, and content distribution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make viewing of a content using a P2P (peer-to-peer) terminal start quickly.SOLUTION: A P2P terminal 1 comprises: a P2P communication unit 11 for performing P2P communication with another P2P terminal; and a HTTP distribution reproduction unit 12 for receiving segmented data and reproducing it. The HTTP distribution reproduction unit 12 transmits a request for information including an acquisition destination URL for the segmented data to a viewing start assistance server 2; the viewing start assistance server 2 transmits a response including the acquisition destination URL for the segmented data to the HTTP distribution reproduction unit 12 in response to the request. The HTTP distribution reproduction unit 12 receives the segmented data from the acquisition destination URL and reproduces it. The P2P communication unit 11 performs participation processing to a P2P network; the HTTP distribution reproduction unit 12 changes its acquisition destination for segmented data to the P2P communication unit 11 when the participation processing by the P2P communication unit 11 is completed.

Description

  The present invention relates to a content distribution system, a P2P terminal, a viewing start auxiliary server, and a content distribution method.

  In recent years, streaming video distribution services have become widespread on the Internet. In addition to a one-to-one distribution service such as VOD (Video On Demand) that selects content to be viewed at the receiving terminal and receives the selected content from the distribution server, the same content is simultaneously transmitted to many receiving terminals. One-to-many (broadcast type) distribution services are known.

  Furthermore, IP multicast is known as a method for efficiently performing a broadcast-type moving image distribution service in an IP network. However, in this IP multicast method, a dedicated network for the communication carrier is required, and it is difficult to provide a service across a plurality of carriers.

  Against this background, a distributed content distribution technology using peer-to-peer technology has been devised in order to enable a broadcast-type video distribution service that spans multiple carriers without requiring a dedicated network for carriers. Such a technique realizes multicast (one-to-many communication) by creating a logical tree between terminals that request content, and application software that operates on the terminals mutually transfers data (see, for example, Patent Document 1). .

  In the stream data distribution and delivery method described in Patent Document 1, each node transmits and receives stream data between nodes in a network environment such as the Internet, and each node has topology information indicating a connection relationship between an upstream node and a downstream node. And the stream data is relayed from the upstream node to the downstream node. This stream data distributed delivery method has a function of performing management such that each node autonomously stores and updates topology information and further provides it in order to exchange topology information between the nodes.

  As another example of such a content distribution method, in the distribution server, the streaming media is fragmented into a plurality of data packets (the fragmented data is called a chunk), and each terminal has a terminal having a necessary chunk. A technique for dynamically detecting, receiving a chunk in a pull type from the detected terminal, and reconfiguring the received chunk to obtain a desired streaming media is known (see, for example, Non-Patent Document 1). .

  FIG. 17 is a diagram illustrating an example of a content distribution system. In this example, the odd numbered chunks are transferred along the solid line and the even numbered chunks are transferred along the broken line among the six chunks 1 to 6 divided by the distribution server 5, as shown in the figure. It shows a state in which all chunks are in perfect reach for each of six terminals (user terminals). In such a content distribution system using a P2P network, the terminal (P2P terminal) relays the content transmitted from the distribution server one after another, thereby reducing the load on the distribution server, which is large at low cost. It is expected as a method for realizing large-scale distribution (hereinafter referred to as “P2P distribution”).

  FIG. 18 is a diagram illustrating a general procedure in which a new P2P terminal joins a P2P network and starts viewing. With reference to this figure, a procedure until a new P2P terminal joins the P2P network and starts viewing will be described. The terminal management server 6 is a server that manages information on P2P terminals participating in the P2P network. A P2P terminal (P2P terminal X) newly participating in the P2P network registers its terminal information (IP address, port number, etc.) in the terminal management server 6 (step 1). The terminal management server 6 returns a list of other P2P terminals A, B, C... Currently participating in the P2P network and the terminal information of the distribution server 5 (step 2). The P2P terminal X selects and connects a P2P terminal suitable for itself from the received list, thereby participating in the P2P network, receiving content, and starting viewing (step 3).

  In addition, P2P application software (P2P terminal) operating on a general-purpose OS is generally implemented by combining viewing player software that reproduces content and P2P communication software that has a content relay function using a predetermined P2P communication protocol.

  FIG. 19 is a diagram illustrating an example of the configuration of the P2P application software. The viewing player software includes pre-installed software (for example, Windows Media Player (registered trademark) and QuickTime Player (registered trademark)) preinstalled in the OS, and software provided as a plug-in for a web browser (for example, Flash Player (registered trademark) and Silverlight (registered trademark). The viewing player is, for example, H.264. In addition to stream decoding functions and video presentation functions according to international standards (ISO) such as H.264 and AAC, streams via the network can be streamed using vendor-specific protocols and streaming protocols based on HTTP communication standards. It has an interface to receive.

  The P2P communication software 32 participates in the P2P network by a predetermined P2P communication protocol, relays the content, and stores the content in the content buffer. Further, the P2P communication software 32 has a server function in which the streaming protocol supported by the viewing player software 31 is implemented, and behaves like a distribution server for the viewing player software 31. By combining these two softwares, the content received by the P2P communication software 32 using the predetermined P2P communication protocol is distributed to the viewing player software via the local communication interface, and the content input by the viewing player software 31 is reproduced. By doing so, the user can view the content.

  By the way, in recent video distribution, a transition from a streaming distribution method using a dedicated server and a dedicated protocol to a method of streaming distribution using an HTTP protocol by a general-purpose web server is progressing, and distribution for many devices In the mainstream. As such a streaming distribution method (adaptive streaming) based on the HTTP protocol, IT vendors have spread their own technologies, and international standards are being developed to unify these streaming methods (for example, non-patents). Reference 2). The basic concepts of both technologies are the same, and the Web server describes video content divided into files of several seconds to several tens of seconds (segmented data), and the attributes and URLs of those video content. A manifest file is prepared, and the terminal receives segmented data one after another according to the URL of the manifest file, and joins and reproduces it to one moving image content.

  In the streaming distribution method based on the HTTP protocol, segmented data is sequentially generated (see, for example, Non-Patent Document 3). FIG. 20 is a diagram illustrating the concept of a streaming distribution method based on the HTTP protocol. Here, the content encoded by the live encoder is divided with the progress of time, and 1 to 6 segmented data are sequentially generated. Similarly, the contents of the manifest are updated as segmented data is generated. That is, the leftmost manifest file has URLs of 1 to 3 segmented data registered, and the next manifest file has URLs of 2 to 4 segmented data registered in order. The segmented data URLs are slid by a certain number. The segmented data and the manifest are sequentially supplied to the web server. The terminal receives the manifest file from the Web server, and sequentially receives the segmented data registered in the manifest file using the HTTP protocol. A series of contents can be received by receiving the updated manifest file and repeating the process of receiving newly registered segmented data (hereinafter referred to as “HTTP delivery”).

  In the content distribution system using the P2P network, when compared with the HTTP distribution method in which the user terminal individually receives the content from the distribution server 5, the P2P terminal relays the content transmitted from the distribution server 5 one after another. While reducing the load on the distribution server 5 and realizing large-scale distribution at low cost, prior to receiving the content, search for and connect to other P2P terminals that join the P2P network and become the content distribution source Since it was necessary to establish, it took a lot of time to start viewing.

  In addition, in the P2P application, the viewing player software connects to the P2P communication software via the local communication interface and starts viewing. Therefore, prior to the viewing player software, the P2P communication software is activated and the stream from the viewing player is started. It is necessary to wait for a request. Since the P2P communication software needs to accept connections from other P2P terminals (such as PCs), a message prompting the OS to set the firewall function is displayed when the software is started, and the user is required to wait for user interaction. It may take some time before. As described above, when it takes time to start the P2P communication software, there is a problem that the waiting time until the reproduction is further increased.

  As a technique for shortening the waiting time until such playback, streaming playback for the purpose of quickly starting streaming playback of content in a content streaming playback apparatus accommodated in a network together with a plurality of data providing nodes An apparatus, a streaming reproduction method, a computer program, and a storage medium are disclosed (for example, see Patent Document 2).

JP 2003-169089 A International Publication No. 2012/053047

CoolStreaming / DoNet: A Data-Driven Overlay Network for Efficient Live Media Streaming ”, In Proc. Of the 24th IEEE INFOCO, March 2005, p. 2102-2111 Xinyan Zhang, Jiangchuan Liu, Bo Li and Tak-Shing Peter Yum “Technology overview and standardization / related technology trends of next-generation video distribution technology“ MPEG-DASH ”, Journal of the Institute of Image Information and Television Engineers, Vol.67, No.2, 2013, p.109-115

  According to the technique described in Patent Document 2, the communication start status is specified by specifying the communication state with each of a plurality of data providing nodes (P2P terminals), and the data required to start streaming playback is subdivided. A request protocol for requesting a plurality of detailed data is generated between each data providing node so that the transfer time from the time when the request protocol for the fragmented data is transmitted to the point when the transfer of the fragmented data ends is even. By doing so, the time required to acquire the reproduction start data is shortened.

  However, the technique described in Patent Document 2 is premised on a state in which communication with a plurality of data providing nodes is possible in advance (that is, a state in which a P2P network has been established in advance). The time required to search for another P2P terminal (data providing node) that participates and serves as a content distribution source is not considered, and viewing may not be started quickly. Furthermore, since the time required for starting the P2P communication software is not taken into consideration, there are cases where viewing cannot be started quickly.

  An object of the present invention made in view of such circumstances is to provide a content distribution system, a P2P terminal, a viewing start auxiliary server, and a content distribution method capable of quickly starting viewing of content by a P2P terminal. is there.

  In order to solve the above problems, a content distribution system according to the present invention includes a P2P terminal that can participate in a P2P network, and a viewing start auxiliary server that assists in obtaining segmented data that is a content division unit in the P2P terminal. A P2P terminal includes a P2P communication unit that performs P2P communication with another P2P terminal, and an HTTP distribution reproduction unit that receives and reproduces segmented data, and the HTTP distribution reproduction unit Transmits a request for information including an acquisition destination URL of segmented data to the viewing start auxiliary server, and when the viewing start auxiliary server receives the request from the HTTP distribution reproduction unit, the acquisition destination URL of segmented data Is sent to the HTTP delivery / playback unit, and the HTTP The communication reproduction unit receives and reproduces the segmented data from the acquisition URL of the segmented data, the P2P communication unit performs a process of joining the P2P network, and the HTTP distribution reproduction unit includes the P2P communication unit When the participation process to the P2P network by is completed, the acquisition source of the segmented data is changed to the P2P communication unit.

  Furthermore, in the content distribution system according to the present invention, the P2P communication unit transfers the request for the viewing start auxiliary server of the HTTP distribution reproduction unit to the P2P communication unit when the participation process to the P2P network is completed. When the request start request server receives the request transfer request from the P2P communication unit, the request start request server transmits the request from the HTTP distribution reproduction unit to the P2P communication. When the request is transferred from the viewing start auxiliary server, the P2P communication unit updates the acquisition destination URL of the segmented data to the URL of the P2P communication unit, and the updated segmented data A response including the URL to obtain the URL is sent to the HTTP delivery / playback unit To.

  Furthermore, in the content distribution system according to the present invention, the P2P communication unit starts viewing the request transfer request when the number of stored segmented data received from other P2P terminals exceeds a predetermined value. Send to auxiliary server.

  In order to solve the above problems, a P2P terminal according to the present invention is a P2P terminal that can participate in a P2P network, receives a segmented data from a P2P communication unit that performs P2P communication with other P2P terminals. An HTTP delivery / playback unit for playing back, wherein the HTTP delivery / playback unit transmits a request for information including an acquisition URL of the segmented data to the viewing start auxiliary server, and A response including a segmentation data acquisition destination URL is received from the server, and the segmented data is received and reproduced from the segmentation data acquisition destination URL. The P2P communication unit performs a process of joining the P2P network, The HTTP delivery / reproduction unit completes the process of joining the P2P network by the P2P communication unit To change the acquisition destination of the segmented data to the P2P communication unit.

  Further, in the P2P terminal according to the present invention, the P2P communication unit transfers the request to the viewing start auxiliary server of the HTTP delivery / playback unit to the P2P communication unit when the participation process to the P2P network is completed. When the request is transferred from the viewing start auxiliary server, the P2P communication unit sends the URL for acquiring the segmented data to the URL of the P2P communication unit. And a response including the URL for obtaining the updated segmented data is transmitted to the HTTP delivery / playback unit.

  Furthermore, in the P2P terminal according to the present invention, the P2P communication unit receives the request transfer request when the stored number of segmented data received from another P2P terminal exceeds a predetermined specified value. Send to server.

  In order to solve the above problem, a viewing start auxiliary server according to the present invention is a viewing start auxiliary server that assists in obtaining segmented data that is a content division unit in a P2P terminal. A request for information including a URL for obtaining segmented data from the HTTP delivery / playback unit, comprising a P2P communication unit for performing P2P communication with a P2P terminal, and an HTTP delivery / playback unit for receiving and playing back the segmented data. In response to the request, a response including the URL for obtaining the segmented data is transmitted to the HTTP delivery / reproduction unit, and a request transfer request for requesting the request to be transferred to the P2P communication unit is received from the P2P communication unit. The request from the HTTP delivery / playback unit is transferred to the P2P communication unit.

  In order to solve the above problems, a content distribution method according to the present invention includes a P2P terminal that can participate in a P2P network, and a viewing start auxiliary server that assists in obtaining segmented data that is a content division unit in the P2P terminal. The P2P terminal includes a P2P communication unit that performs P2P communication with other P2P terminals, and an HTTP distribution reproduction unit that receives and reproduces the segmented data. The HTTP delivery / playback unit transmits a request for information including the URL for obtaining segmented data to the viewing start auxiliary server, and the viewing start auxiliary server receives the request from the HTTP delivery / playback unit. Then, the response including the URL for acquiring the segmented data To the HTTP delivery / reproduction unit, to receive and reproduce the segmented data from the acquisition URL of the segmented data by the HTTP delivery / reproduction unit, and to the P2P network by the P2P communication unit And a step of changing the acquisition source of the segmented data to the P2P communication unit when the HTTP distribution / playback unit completes the participation process to the P2P network by the P2P communication unit. .

  According to the present invention, viewing can be quickly started without waiting for the end of the P2P network participation process.

It is a block diagram which shows the structural example of the content delivery system which concerns on one Embodiment of this invention. It is a figure which shows an example of the viewing-and-listening page which a Web server transmits. It is a block diagram which shows the structural example of the viewing-and-listening start assistance server which concerns on one Embodiment of this invention. It is a figure which shows an example of a manifest file. It is a block diagram which shows the structural example of the segment buffer of the viewing-and-listening auxiliary server which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of the P2P terminal which concerns on one Embodiment of this invention. It is a figure which shows an example of the state of the content buffer of the P2P terminal which concerns on one Embodiment of this invention. It is a figure which shows an example of the manifest with respect to the state of the content buffer of the P2P terminal which concerns on one Embodiment of this invention. It is a sequence diagram which shows starting operation | movement of the P2P terminal which concerns on one Embodiment of this invention. It is a flowchart which shows the operation | movement of the P2P communication process of the P2P terminal which concerns on one Embodiment of this invention. It is a flowchart which shows the P2P network participation process of the P2P terminal which concerns on one Embodiment of this invention. It is a sequence diagram which shows the request transfer request process with respect to the viewing assistance start server of the P2P terminal which concerns on one Embodiment of this invention. It is a flowchart which shows the HTTP server process of the P2P terminal which concerns on one Embodiment of this invention. It is a flowchart which shows the operation | movement concerning the HTTP request of the viewing-and-listening auxiliary server which concerns on one Embodiment of this invention. It is a flowchart which shows the HTTP delivery reproduction | regeneration processing of the P2P terminal which concerns on one Embodiment of this invention. It is a figure which shows an example of the message format of an HTTP request / HTTP response. It is a figure which shows an example of the conventional content delivery system. It is a flowchart which shows the P2P network participation process of the conventional P2P terminal. It is a figure which shows an example of a structure of the conventional P2P application software. It is a figure which shows the concept of the streaming delivery system by the conventional HTTP protocol.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the embodiment described below, a content distribution unit (division unit) for data relay of P2P distribution is made common to segmented data that is a content distribution unit in HTTP distribution.

  FIG. 1 is a block diagram showing a configuration example of a content distribution system according to an embodiment of the present invention. In this example, the content distribution system includes a plurality of P2P terminals 1, a viewing start auxiliary server 2, an origin server 3, a Web server 4, a distribution server 5, and a terminal management server 6, each connected to the Internet. Is done. In FIG. 1, the viewing start auxiliary server 2, the origin server 3, the web server 4, the distribution server 5, and the terminal management server 6 are shown as separate servers. You may have the function of. Further, in the following description, a newly participating P2P terminal that newly participates in the P2P network is distinguished from other P2P terminals that have already participated in the P2P network and are connection destination candidates or connection destinations of the newly participating P2P terminal. In this case, the code of the other P2P terminal is expressed as 1 ′.

  The origin server 3 is a server that is a content distribution source, divides the content into segmented data, generates a manifest, and transmits the manifest to the viewing start auxiliary server 2 and the distribution server 5.

  The distribution server 5 is a server that sequentially distributes the segmented data received from the origin server 3 to the P2P terminals 1 'participating in the P2P network. The P2P network is configured by hierarchically connecting the distribution server 5 and the P2P terminal 1 '.

  The terminal management server 6 holds a list of terminal information, which is information related to the content distribution of the distribution server 5 and each P2P terminal 1 ′ participating in the P2P network of the content distribution system of the present invention, and is a newly participating P2P terminal 1 Accepts a connection destination introduction request for the P2P network with the desired content ID from the server, and returns a connection destination candidate list. The terminal information includes information necessary for data transfer such as an IP address and a port number in association with the terminal IDs of the distribution server 5 and the P2P terminal 1 ′ participating in the P2P network. The connection destination candidate list is a list including one or more pieces of terminal information of the distribution server 5 and the P2P terminal 1 ′ that are already participating in the P2P network and are candidates for the connection destination of the newly participating P2P terminal 1.

  The Web server 4 is a server that transmits a viewing page of content selected by the user in the P2P terminal 1. The viewing page is composed of, for example, a web page in the HTML format, and access information to the content (IP address, URL, content ID, etc.), access information for viewing player software and P2P communication software constituting the P2P application, and these software Tag information that prompts activation of the terminal, a terminal ID uniquely assigned to the P2P application, and the like.

  FIG. 2 is a diagram illustrating an example of a viewing page transmitted by the Web server. In this example, the 4th to 7th lines indicate viewing player software activation tags, and the viewing player software is implemented using Flash Player. Looking inside the tag, the fifth line shows the access information (download URL) of the viewing player software, and “src = http: //192.168.11.1/content01.m3u8” on the sixth line is the access information to the content “Nid = 0001” indicates the terminal ID.

  The 10th to 13th lines indicate P2P communication software activation tags, and an example in which the P2P communication software is implemented using Java Applet (registered trademark). Looking inside the tag, the 10th line shows the access information (download URL) of the P2P communication software, the 11th line shows the access information (content ID) to the content, and the 12th line shows the terminal ID. Yes.

  The P2P terminal 1 includes a P2P communication unit 11 that performs P2P communication with another P2P terminal 1 ′, and an HTTP distribution reproduction unit 12 that receives and reproduces the segmented data. Details will be described later.

[Viewing start auxiliary server]
Next, the viewing start auxiliary server 2 will be described. The viewing start auxiliary server 2 is a server that receives the segmented data and the manifest from the origin server 3, transmits the manifest and the segmented data in response to the request from the P2P terminal 1, and forwards the acquisition destination of the manifest. The viewing start auxiliary server 2 assists the acquisition of the segmented data in the P2P terminal, and until the P2P terminal 1 completes the participation process of the P2P network and can accept the HTTP distribution request, the manifest and the segmentation Data is transmitted to the P2P terminal 1.

  FIG. 3 is a block diagram illustrating a configuration example of the viewing start auxiliary server 2. The viewing start auxiliary server 2 includes a distribution material receiving unit 21, an HTTP request receiving unit 22, a request analyzing unit 23, an HTTP response transmitting unit 24, a request transfer request receiving unit 25, a storage unit 26, a communication I / F27. The storage unit 26 includes a transfer waiting list 261, a segment buffer 262, and a manifest storage unit 263.

  The transfer waiting list 261 is a list that stores a transfer enable / disable flag and transfer destination address information in association with the terminal ID. The transfer enable / disable flag is a flag indicating whether or not the request for the manifest of the terminal ID can be transferred. The transfer destination address information is address information (a pair of an IP address and a port number or a URL) that is a transfer destination of a request when the transfer enable / disable flag is “transfer enabled”.

  The segment buffer 262 stores segmented data.

  The manifest storage unit 263 stores the manifest in association with the sequence number of the first segmented data in the manifest.

  The distribution material receiving unit 21 receives the segmented data from the origin server 3 and sequentially stores the segmented data in the segment buffer 262. The distribution material receiving unit 21 also receives a manifest describing the URL of the segmented data, and the sequence of the first segmented data in the manifest. The number is stored in the manifest storage unit 263 in association with the number.

  In the present embodiment, the manifest and segmented data input from the origin server 3 are set in advance so that the number of segmented data described in the manifest is 5 and the segmentation data division period is 3 seconds. And

  FIG. 4 is a diagram illustrating an example of a manifest, and illustrates an example of a manifest according to the specification of “HTTP Live Streaming”, which is an Internet draft of IETF (Internet Engineering Task Force). For details of “HTTP Live Streaming”, refer to the Internet <URL: http://tools.ietf.org/html/draft-pantos-http-live-streaming-12>, for example.

  FIG. 4 shows an example in which there is an acquisition destination URL of 5 segmented data (ts file) of 3 seconds starting with sequence number (segment Id) = 14. The file name of the segmented data is a character string obtained by concatenating “content name” (content01_), “segment Id”, zero-padded 5 digits (for example, 00001), and “extension” (.ts). The number of segments described in the manifest is a fixed number (for example, 5), and each time new segmented data is received, the information of the first segmented data is deleted and the latest segmented data is added to the end. The IP address “192.168.11.1” in the drawing indicates the IP address of the viewing start auxiliary server 2.

  The HTTP request reception unit 22 receives a request (HTTP request) based on the HTTP protocol from the HTTP distribution reproduction unit 12 of the P2P terminal 1 via the communication I / F 27, and outputs the received HTTP request to the request analysis unit 23.

  The request analysis unit 23 analyzes the HTTP request. If the request content is segmented data (ts file), the request analysis unit 23 instructs the HTTP response transmission unit 24 to transmit the segmented data.

  When the request content is a manifest, the request analysis unit 23 extracts the terminal ID from the HTTP request. When the terminal ID is not stored in the transfer waiting list 261, the “transfer enable / disable flag” is newly registered as “transfer disabled”, and the terminal ID is output to the HTTP response transmitting unit 24 and the manifest is transmitted. Instruct.

  When the request analysis unit 23 instructs the HTTP response transmission unit 24 to transmit segmented data, the HTTP response transmission unit 24 inputs the segmented data from the segment buffer 262 and sends an HTTP response to the HTTP distribution reproduction unit 12 of the P2P terminal 1. Send to. When the request analysis unit 23 instructs to transmit a manifest, a transfer enable / disable flag corresponding to the terminal ID input from the request analysis unit 23 is extracted from the transfer waiting list 261, and “transfer disable” is indicated. If it is, the manifest is input from the manifest storage unit 263, and an HTTP response is transmitted to the HTTP delivery / reproduction unit 12 of the P2P terminal 1. The manifest transmitted at this time will be described with reference to FIG. A plurality of manifests are managed in association with the leading sequence number.

  FIG. 5 is a diagram showing the contents of the segment buffer 262 corresponding to the passage of time. The segment buffer 262 has a predetermined size. The segmented data of sequence numbers 11 to 20 is stored in the segment buffer 262 at the current time. When new segmented data is input, the oldest segmented data is stored. Data shall be deleted.

  The transmitted manifest is the sum of the buffer specified value (2) set in advance and the number of segmented data (5) described in the manifest from the sequence number (20) of the latest segmented data existing in the buffer at the current time. It is assumed that the manifest is associated with the sequence number (14) traced back by this value. Here, the buffer specified value is a margin of the buffer of the P2P communication unit 11 (P2P communication software) with respect to the HTTP delivery / reproduction unit 12 in the P2P terminal 1, and the latest segmented data that the HTTP delivery / reproduction unit 12 can acquire. It shows the number of segmented data that is newer and currently available. As the buffer specified value increases, viewing stability increases, while the difference between the current time and the time of segmented data being viewed increases.

  On the other hand, if the transfer enable / disable flag is “transfer ready”, the transfer destination address information corresponding to the terminal ID is extracted from the transfer waiting list 261, and the status code of the HTTP header is set to “302 Found”. Based on the transfer destination address information, a transfer destination URL of the manifest is generated. For example, Location: http://127.0.0.1:5555/content01.m3u8 is described in the “Location” header, and the P2P terminal 1 (HTTP distribution) To the playback unit 12).

  The request transfer request receiving unit 25 receives a request transfer request from the P2P communication unit 11 of the P2P terminal 1, extracts the terminal ID and transfer destination address information, and transfers the transfer permission / inhibition flag corresponding to the terminal ID of the transfer waiting list 261. Is set to “transfer ready”, and the transfer destination address information is registered in the transfer waiting list 261. Further, the current manifest is extracted from the manifest storage unit 263 and transmitted to the P2P terminal 1.

[P2P terminal]
Next, details of the P2P terminal 1 will be described. The P2P terminal 1 can participate in the P2P network, and is connected to the distribution server 5 and other P2P terminals 1 to receive, transfer, and play back the segmented data, and receives the segmented data from the viewing start auxiliary server 2 It is a terminal to play.

  FIG. 6 is a block diagram showing a configuration example of the P2P terminal 1 of the present invention. In this example, each P2P terminal 1 includes a P2P communication unit 11, an HTTP distribution / playback unit 12, a communication I / F 13, and a local communication I / F 14.

  The P2P communication unit 11 includes a connection destination introduction request unit 111, a connection control unit 112, a data relay unit 113, a request transfer request unit 114, a storage unit 115, an HTTP server unit 116, and a manifest update unit 117. Prepare. The storage unit 115 includes a terminal information storage unit 1151, a content buffer 1152, a manifest storage unit 1153, and an HTTP server address information storage unit 1154.

  The connection destination introduction request unit 111 transmits a connection destination introduction request including the content ID of the desired content, the terminal ID, and address information (information necessary for data transfer such as an IP address and a port number) to the terminal management server 6. The connection destination candidate list returned from the terminal management server 6 is received and stored in the terminal information storage unit 1151.

  Based on the connection destination candidate list, the connection control unit 112 selects and connects the P2P terminal 1 ′ or the distribution server 5 that is a connection partner in the P2P network, or accepts a connection from another P2P terminal 1 ′. .

  The data relay unit 113 sequentially receives the segmented data from the latest sequence number at the start of data relay from the P2P terminal 1 'located upstream in the P2P network configured in a hierarchical connection. The segmented data is relayed to another P2P terminal 1 ′ and stored in the content buffer 1152 of the storage unit 115.

  The request transfer request unit 114 checks the content buffer 1152, and at the timing when the number of segmented data stored becomes equal to or greater than a preset buffer specified value (same as the buffer specified value shown in FIG. 5), And the transfer request including the HTTP server address information is transmitted to the viewing start auxiliary server 2, and the received manifest is stored in the manifest storage unit 1153 (implemented only once after activation). Here, the HTTP server address information is address information at which the HTTP server unit 116 accepts an HTTP request from the HTTP distribution / playback unit 12, and is composed of a set of an IP address and a port number.

  The HTTP server unit 116 has a server function of receiving a transmission request for HTTP distribution from the HTTP distribution reproduction unit 12 and transmitting the manifest and the segmented data to the HTTP distribution reproduction unit 12. When receiving a manifest request from the HTTP delivery / playback unit 12, the HTTP server unit 116 inputs the manifest from the manifest update unit 117 and transmits the manifest to the HTTP delivery / playback unit 12. When receiving a request for segmented data from the HTTP delivery / playback unit 12, the HTTP server unit 116 extracts the segmented data of the sequence number from the content buffer 1152 of the storage unit 115 and transmits it to the HTTP delivery / playback unit 12. To do.

  The manifest update unit 117 updates the manifest stored in the manifest storage unit 1153 based on the state of the segmented data in the content buffer 1152. A manifest updating method by the manifest updating unit 117 will be described with reference to FIGS.

  FIG. 7 is a diagram illustrating an example of the state of the content buffer 1152. FIG. 8 is a diagram showing an example of a manifest for the state of the content buffer 1152. The number of stored segments of the manifest generated by the P2P communication unit 11 is the number obtained by adding the buffer specified value to the number of segments of the manifest generated by the origin server 3. In the present embodiment, the number of manifest segments generated by the origin server 3 is 5, and the buffer specified value is 2.

  FIG. 8A shows a manifest received from the viewing start auxiliary server 2 by the request transfer request unit 114, which is an initial value of the manifest (hereinafter referred to as an initial manifest). The IP address “192.168.11.1” in the figure indicates the IP address of the viewing start auxiliary server 2. In this embodiment, the initial segmentation data acquisition destination URL is the viewing start auxiliary server 2, but the segmentation data acquisition destination URL may be another server.

  The buffer state 1 in FIG. 7A shows a state in which the number of segmented data in the content buffer 1152 is smaller than the number of stored segments soon after the P2P communication unit 11 is activated. Buffer state 2 shows a state in which segmented data equal to or more than the number of segments stored in the manifest is stored in the content buffer 1152.

  When updating the manifest, the segmented data with the sequence number that goes back from the current time to the number of storage segments is used as the head, and the segmented data with the latest sequence number is stored.

  The buffer state 1 includes segmented data (16 to 19 in the buffer state 1 in FIG. 7A) that is not stored in the content buffer 1152, that is, before the start time of data relay. Therefore, the acquisition destination URL of the sequence number described in the initial manifest is used as the acquisition destination URL of the segmented data. The acquisition URL of the segmented data stored in the content buffer 1152 is generated based on its own HTTP server address information. FIG. 8B shows an example of the manifest in the buffer state 1. In FIG. 8B, the acquisition destination URLs of the segmented data from the top to the fourth are the viewing start auxiliary server 2 (“192.168.11.1”), and the acquisition destinations from the fifth to the seventh are acquired. The URL is its own HTTP server unit 116. Here, “127.0.0.1:5555” indicates HTTP server address information. In this example, “127.0.0.1” is an IP address and “5555” is a port number.

  In the buffer state 2, since all segmented data is stored in the content buffer 1152, the segmented data acquisition URL is generated based on its own HTTP server address information. FIG. 8C shows an example of the manifest in the buffer state 2. In FIG. 8C, the acquisition destination URL of all segmented data is the HTTP server unit 116 of the P2P communication unit 11.

  The HTTP delivery / reproduction unit 12 includes a manifest request destination storage unit 121, a manifest request unit 122, a manifest reception unit 123, a manifest analysis unit 124, a segment reception unit 125, a reproduction buffer 126, and a content reproduction unit 127. Prepare. When the P2P communication unit 11 completes the process of joining the P2P network, the HTTP distribution / playback unit 12 switches the segmented data acquisition destination from the segmented data acquisition destination URL to the P2P communication unit 11.

  The manifest request destination storage unit 121 is a storage unit that stores address information of a manifest acquisition destination. At the time of start-up, the acquisition destination URL of the manifest including the address information of the viewing start auxiliary server 2 described in the viewing page acquired from the Web server 4 is stored.

  The manifest request unit 122 inputs a manifest acquisition URL from the manifest request destination storage unit 121, and transmits an HTTP request including the terminal ID to the viewing start auxiliary server 2. For example, when the manifest acquisition URL is “http://192.168.11.1/content01.m3u8” and the terminal ID is “0001”, the query parameter is added as “? Nid = 0001” to the manifest acquisition URL. Then, “http://192.168.11.1/content01.m3u8?nid=0001” is described in the request line of the HTTP request. The manifest request may be periodically made every predetermined time (for example, 1 second), or may be made after receiving all the segmented data described in the manifest.

  If the status code included in the received HTTP response is “200”, the manifest receiving unit 123 receives the manifest from the manifest request destination and outputs it to the manifest analyzing unit 124. When the status code included in the received HTTP response is “301”, “302”, or “307”, the transfer destination URL is extracted from the “Location” header of the HTTP response header, and the manifest request destination In addition to storing in the storage unit 121, the manifest reception unit 123 is instructed to transmit an HTTP request to the transfer destination URL.

  The manifest analysis unit 124 extracts information on the acquisition destination URL of the segmented data associated with the sequence number from the manifest, and transmits an HTTP request for the acquisition destination URL of the segmented data to the segment reception unit 125 in order of the sequence number. To instruct.

  Based on the instruction from the manifest analysis unit 124, the segment receiving unit 125 sequentially transmits HTTP requests to the segmentation data acquisition destination URL, receives the segmented data from the acquisition destination URL, and stores the segmented data in the reproduction buffer 126.

  The content playback unit 127 sequentially inputs segmented data from the playback buffer 126, decodes the input segmented data, and plays back the content.

[Content delivery method]
Next, a content distribution method according to an embodiment of the present invention will be described using the flowcharts of FIGS. An example of the message format of the HTTP request / HTTP response used in the description is shown in FIG. The HTTP request / HTTP response is divided into a header part and a body part above and below the line feed code, and the top line of the HTTP response header includes a status code. The body part may not exist.

  FIG. 9 is a flowchart showing the starting operation of the P2P terminal 1. The P2P terminal 1 acquires the viewing page of the selected content from the Web server 4 (step S1001), and viewing / listening player software (HTTP distribution / playback unit 12) and P2P communication software (P2P communication unit 11) of the viewing page (see FIG. 2). ) Is executed in parallel by the HTTP delivery processing unit 12 (step S1002) and the P2P communication unit 11 by the P2P communication unit 11 (step S1003). Thus, the P2P terminal 1 is activated and executes a series of processes. Details of the P2P communication process (step S1003) will be described later with reference to FIGS. 10 to 13, and details of the HTTP distribution process (step S1002) will be described later with reference to FIG.

  FIG. 10 is a flowchart showing the operation of the P2P communication process by the P2P communication unit 11. The content ID and terminal ID of the content selected from the viewing page are acquired and stored in the terminal information storage unit 1151 (step S1101). Next, it participates in the P2P network based on the content ID and the terminal ID (step S1102). Details of step S1102 will be described later with reference to FIG.

  When the P2P terminal 1 participates in the P2P network, the data relay unit 113 sequentially transmits the connection destination P2P terminal 1 ′ or the distribution from the segmented data of the latest sequence number at the data relay start time (the time when the process first entered). A request is made to the server 5 (step S1103). When the P2P terminal 1 receives the segmented data (step S1104-YES), the P2P terminal 1 stores the received segmented data in the content buffer 1152 (step S1105). If segmented data has not been received (step S1104-NO), the process proceeds to step S1106.

  Next, it is confirmed whether or not the HTTP server unit 116 is being activated (step S1106). If the HTTP server unit 116 is being activated (step S1106—YES), the process proceeds to step S1111. In the initial state, it is not being activated (NO in step S1106). If the HTTP server unit 116 has not been activated (NO in step S1106), it is confirmed whether the number of segmented data stored in the content buffer 1152 exceeds the buffer specified value (step S1107). If the buffer specified value is not exceeded (step S1107-NO), the process returns to step S1103. If the buffer specified value is exceeded (step S1107-YES), the HTTP server unit 116 is activated (step S1108), and the HTTP is set. The server address information is stored in the HTTP server address information storage unit 1154 (step S1109).

  Next, the request transfer request unit 114 requests the viewing start auxiliary server 2 to transfer a request for the viewing start auxiliary server 2 of the HTTP distribution reproduction unit 12 to the P2P communication unit 11 (step S1110). Details of step S1110 will be described later with reference to FIG.

  With the processing so far, the preparation for the P2P communication unit 11 to receive the HTTP request from the HTTP distribution reproduction unit 12 is completed, and the process proceeds to the HTTP server processing (step S1111). Details of step S1111 will be described later with reference to FIG. Next, it is confirmed whether or not the reproduction is finished (step S1112). If the reproduction is finished (step S1112-YES), the process is finished, and if the reproduction is not finished (step S1112-NO). Return to step S1103.

  FIG. 11 is a sequence diagram showing a P2P network participation process (step S1102) by the P2P communication unit 11. The connection destination introduction request unit 111 of the P2P communication unit 11 transmits a connection destination introduction request including a content ID, a terminal ID, and address information to the terminal management server 6 (step S1201).

  The terminal management server 6 updates the list of terminal information with the received terminal information, and extracts a plurality of pieces of terminal information of the P2P terminal 1 ′ or distribution server 5 participating in the P2P network that relays the content with the content ID (step) In step S1202), the connection destination candidate list is transmitted to the P2P communication unit 11 of the P2P terminal 1 (step S1203).

  Next, the connection destination introduction request unit 111 of the P2P communication unit 11 receives the connection destination candidate list from the connection destination introduction response, and stores it in the terminal information storage unit 1151 (step S1204). Let N be the number of received lists. Next, the loop counter I is set to 0 (step S1205). When I is smaller than N (step S1206-YES), the connection control unit 112 extracts the I-th terminal information (step S1207), and the I-th A connection request is transmitted to the P2P terminal 1 ′ (step S1208). If there is a response within a predetermined time (for example, 2 seconds) (step S1209), the connection control unit 112 receives the connection response (step S1210), and if the connection is OK (step S1211-YES), the I-th By establishing a connection with the P2P terminal 1 ′ as an upstream terminal, the mobile terminal joins the P2P network (step S1213). If NO in step S1209 or NO in step S1211, the loop counter is incremented (step S1212), and the process returns to step S1206. Returning to step S1206, if I is greater than or equal to N (step S1206 -NO), the process returns to step S1201.

  As described above, the P2P terminal 1 can connect to the P2P terminal 1 ′ or the distribution server 5 already connected to the P2P network and receive segmented data.

  FIG. 12 is a sequence diagram illustrating a request transfer request process (step S1110) for the viewing start auxiliary server 2 by the P2P communication unit 11. When the content buffer 1152 of the P2P communication unit 11 exceeds the buffer specified value, the P2P communication unit 11 transmits a transfer request including the terminal ID and the transfer destination URL (HTTP server address information) to the viewing start auxiliary server 2 (step) S1301). The viewing start auxiliary server 2 receives the transfer request (step S1302), and extracts the terminal ID and the transfer destination URL from the transfer request (step S1303).

  Next, the viewing start auxiliary server 2 checks whether or not the extracted terminal ID is registered in the transfer waiting list 261 (step S1304). If registered (step S1304-YES), The transfer enable / disable flag of the terminal ID is updated to “transfer ready”, and the extracted transfer destination URL is registered as the transfer destination URL (step S1305). If the terminal ID is not registered in the transfer waiting list 261 (step S1304-NO), the terminal ID is registered in the transfer waiting list 261, the transfer enable / disable flag is set to “transfer ready”, and the transfer destination URL is The extracted transfer destination URL is registered (step S1306). Next, the manifest is extracted from the manifest storage unit 263 and transmitted to the transfer request source (P2P communication unit 11 of the P2P terminal 1) (step S1307). The manifest transmitted at this time is as described in the manifest storage unit 263 of the viewing start auxiliary server 2.

  The P2P communication unit 11 receives the transfer response from the viewing start auxiliary server 2 (step S1308). Then, a manifest is extracted from the received transfer response, stored as an initial manifest in the manifest storage unit 263 (step S1309), and the transfer request process is terminated.

  As described above, when the content buffer 1152 of the P2P communication unit 11 exceeds the buffer specified value, the request for the HTTP delivery / playback unit 12 is requested to be transferred to the P2P communication unit 11 and the viewing start auxiliary server 2 is requested. When the server 2 transfers the request to the HTTP delivery / reproduction unit 12, the HTTP delivery / reproduction unit 12 can make a request to the P2P communication unit 11.

  FIG. 13 is a flowchart showing HTTP server processing (step S1111) by the P2P communication unit 11. The P2P communication unit 11 of the P2P terminal 1 waits for an HTTP request from the HTTP distribution / playback unit 12 via the local communication I / F 14 and receives an HTTP request (step S1401-YES). If the request target is a manifest, segmented data (Step S1402). If the request target is a manifest (step S1402-YES), the manifest is updated from the initial manifest and the contents buffer 1152, and set in the body of the HTTP response (step S1403). The update of the manifest is as described in the manifest update unit 117 of the P2P communication unit 11. Next, the status code of the HTTP response header is set to “200 OK” (step S1404), the HTTP response is transmitted to the HTTP delivery / playback unit 12, and the process ends (step S1405).

  If the request target is segmented data in step S1402 (step S1402-NO), the segment Id is acquired from the request (step S1406), the segmented data of the segment Id is extracted from the content buffer 1152, and HTTP The response body is set (step S1407), and the process proceeds to step S1405.

  As described above, the P2P communication unit 11 can process the request related to HTTP distribution of the HTTP distribution reproduction unit 12 and transmit the content.

  Next, the operation concerning the HTTP request of the HTTP delivery / playback unit 12 of the P2P terminal 1 of the viewing start auxiliary server 2 will be described with reference to FIG. FIG. 14 is a flowchart showing an operation related to the HTTP request of the viewing start auxiliary server 2.

  The viewing start auxiliary server 2 receives the HTTP request from the HTTP delivery / reproduction unit 12 of the P2P terminal 1 (step S2101), and checks whether the request target is a manifest or segmented data (step S2102). If the request target is a manifest (step S2102-YES), the terminal ID is extracted from the request (step S2103).

  Then, the viewing start auxiliary server 2 checks whether or not the extracted terminal ID is registered in the transfer waiting list 261 (step S2104). If the extracted terminal ID is not registered in the transfer waiting list 261 (step S2104-NO), the terminal ID is registered in the transfer waiting list 261, and the transfer enable / disable flag is set to “transfer disable” (step S2105). The manifest is extracted from the manifest storage unit 263 and set in the body of the HTTP response (step S2108). The manifest to be extracted is as described in the manifest storage unit 263 of the viewing start auxiliary server 2. On the other hand, if the extracted terminal ID is registered in the transfer waiting list 261 in step S2104 (YES in step S2104), the transfer enable / disable flag and transfer destination URL of the terminal ID are extracted from the transfer waiting list 261 (step S2104). In step S2106, if the transfer enable / disable flag is “transfer disabled” (step S2107—NO), the process proceeds to step S2108. Next, the status code of the HTTP response header is set to “200 OK” (step S2109), and an HTTP response is transmitted (step S2110).

  Returning to step S2102, if the request target is segmented data (step S2102-NO), the segment Id is acquired from the request (step S2113), and the segmented data of the segment Id is extracted from the segment buffer 262. The HTTP response body is set (step S2114), and the process proceeds to step S2109.

  Returning to step S2107, if the transfer enable / disable flag is “transfer ready” (step S2107—YES), the transfer destination URL is set in the “Location” header of the HTTP response header (step S2111). For example, Location: http://127.0.0.1:5555/content01.m3u8. Then, the status code of the HTTP response header is set to “302 Found” (step S2112), and an HTTP response is transmitted (step S2110).

  Next, it is confirmed whether or not the content has ended. If the content has not ended yet (step S2115-NO), the processing returns to step S2101. If the content has ended (step S2115-YES), the process ends.

  As described above, the viewing start auxiliary server 2 makes a manifestation and segmentation until an HTTP request from the HTTP distribution reproduction unit 12 of the P2P terminal 1 of a certain terminal ID is received from the P2P communication unit 11 of the terminal ID. The P2P terminal 1 plays the role of an HTTP distribution server that transmits data. When there is a transfer request from the P2P communication unit 11, the request from the HTTP distribution reproduction unit 12 is transferred to the HTTP server unit 116 of the P2P communication unit 11. To help you start watching quickly.

  FIG. 15 is a flowchart showing the HTTP delivery / playback operation by the HTTP delivery / playback unit 12. The operation of the HTTP delivery / reproduction unit 12 of the P2P terminal 1 will be described with reference to FIG. The HTTP distribution / playback unit 12 acquires the content access destination URL (viewing start auxiliary server 2) and the terminal ID from the viewing page received from the Web server 4, and the manifest acquisition destination URL is, for example, http://192.168.11.1 Set /content01.m3u8?nid=0001 (step S1501).

  Next, for example, an HTTP request shown in FIG. 16A is transmitted to the acquisition URL of the manifest (step S1502), and when an HTTP response is acquired (step S1503), the status code of the HTTP response is confirmed (step S1503). Step S1504). For example, when the status code is “200” as shown in FIG. 16C (step S1504-YES), the manifest is extracted from the body of the HTTP response (step S1505), and the segmented data is extracted from the extracted manifest. The sequence number and the acquisition destination URL are extracted (step S1506).

  Next, it is confirmed whether a predetermined time (for example, 1 second) has passed since the previous manifest was received, or whether the segmented data described in the manifest has already been acquired (step S1507). Step S1507—YES), the process returns to Step S1502. If neither is satisfied (step S1507-NO), an HTTP request is transmitted to the acquisition URL of the segmented data of the smallest sequence number that has not been acquired (step S1508), and an HTTP response is received (step S1509). The segmented data is extracted from the body of the received HTTP response and stored in the reproduction buffer 126 (step S1510).

  Next, when the content is not yet reproduced (step S1511-NO), it is confirmed whether data necessary for reproduction is stored in the reproduction buffer 126 (step S1512). If the data necessary for reproduction is not yet stored in the reproduction buffer 126 (step S1512—NO), the process returns to step S1507, and if stored (step S1512—YES), reproduction is started. (Step S1513). When reproduction is started or during reproduction (step S1511-YES), the segmented data is sequentially extracted from the reproduction buffer 126 and reproduced (step S1514). If reproduction has not ended (step S1515-NO), the process returns to step S1507. If reproduction has ended (step S1515-YES), the process ends.

  Next, returning to the processing of step S1504, for example, when the status code is other than 200 (302) as shown in FIG. 16D (step S1504-NO), from the “Location” header of the HTTP response header. The transfer destination URL indicating the access information to the HTTP server unit 116 of the P2P communication unit 11 is acquired (step S1516), the acquired transfer destination URL is set as the acquisition destination URL of the manifest, and the process returns to step S1501. FIG. 16B shows an example of an HTTP request for the subsequent manifest.

  The above-described comprehension of the present invention is that the HTTP distribution / playback unit 12 sends a request for information (manifest) including the acquisition URL of the segmented data to the viewing start auxiliary server 2, and the viewing start auxiliary server 2 performs segmentation. A response including the data acquisition destination URL is transmitted to the HTTP distribution reproduction unit 12, and the HTTP distribution reproduction unit 12 receives and reproduces the segmented data from the segmented data acquisition destination URL. Further, the P2P communication unit 11 performs a P2P network participation process, and when the P2P communication unit 11 completes the participation process to the P2P network, the HTTP distribution reproduction unit 12 sets the acquisition destination of the segmented data to the P2P communication. Change to part. As a result, the P2P terminal 1 can quickly start viewing the content without waiting for the end of the P2P network participation process. In addition, when the number of P2P terminals 1 that receive content is small, it is possible to provide a content distribution service only by HTTP distribution, and to switch to P2P distribution when the number of P2P terminals 1 exceeds a predetermined number. It becomes.

  As a specific example of changing the acquisition destination of the segmented data to the P2P communication unit 11 for the HTTP distribution / playback unit 12, when the P2P communication unit 11 completes the P2P network participation process, the HTTP distribution / playback unit 12 starts viewing. A request transfer request for requesting to transfer a request for the auxiliary server 2 to the P2P communication unit 11 is transmitted to the viewing start auxiliary server 2, and the request from the HTTP distribution reproduction unit 12 is transmitted to the viewing start auxiliary server 2 by P2P communication. When the request is transferred from the viewing start auxiliary server 2 in the P2P communication unit 11, the acquisition destination URL of the segmented data is updated to the URL of the P2P communication unit 11, and the updated segment A response including the acquisition URL of the encrypted data is transmitted to the HTTP distribution reproduction unit 12. Thereby, the distribution destination of the content can be switched seamlessly and stably from the viewing start auxiliary server 2 to the P2P communication unit 11. Furthermore, the HTTP delivery / reproduction unit 12 and the P2P communication unit 11 are not necessarily activated simultaneously in the P2P terminal 1, and switching to P2P communication is possible even if the P2P communication unit 11 is activated at an arbitrary timing.

  In addition, the P2P communication unit 11 transmits a request transfer request to the viewing start auxiliary server 2 when the number of stored segmented data received from the other P2P terminal 1 ′ becomes equal to or greater than a predetermined buffer specified value. Is preferred. By providing the buffer specified value, viewing stability can be improved.

  It should be noted that a computer can be suitably used to function as the P2P terminal 1 described above, and such a computer stores a program describing processing contents for realizing each function of the P2P terminal 1 in a storage unit of the computer. It can be realized by reading and executing this program by the CPU of the computer. This program can be recorded on a computer-readable recording medium.

  Similarly, a computer can be suitably used to function as the above-described viewing start auxiliary server 2, and such a computer stores a program describing processing contents for realizing each function of the viewing start auxiliary server 2. This program can be realized by reading out and executing the program by the CPU of the computer. This program can be recorded on a computer-readable recording medium.

  Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications and changes can be made without departing from the scope of the claims. For example, it is possible to combine or divide a plurality of constituent blocks or steps described in the embodiments into one. In the above-described embodiment, the initial segmentation data acquisition destination URL is the viewing start auxiliary server 2, but the segmentation data acquisition destination URL may be another server.

DESCRIPTION OF SYMBOLS 1 P2P terminal 2 View start auxiliary server 3 Origin server 4 Web server 5 Distribution server 6 Terminal management server 11 P2P communication part 12 HTTP distribution reproduction | regeneration part 13 Communication I / F
14 Local communication I / F
21 Delivery material reception unit 22 HTTP request reception unit 23 Request analysis unit 24 HTTP response transmission unit 25 Request transfer request reception unit 26 Storage unit 27 Communication I / F
111 Connection destination introduction request unit 112 Connection control unit 113 Data relay unit 114 Request transfer request unit 115 Storage unit 116 HTTP server unit 117 Manifest update unit 121 Manifest request destination storage unit 122 Manifest request unit 123 Manifest reception unit 124 Manifest analysis unit 125 Segment Reception unit 126 Playback buffer 127 Content playback unit 261 Transfer waiting list 262 Segment buffer 263 Manifest storage unit 1151 Terminal information storage unit 1152 Content buffer 1153 Manifest storage unit 1154 HTTP server address information storage unit

Claims (8)

A content distribution system comprising: a P2P terminal that can participate in a P2P network; and a viewing start assistance server that assists in obtaining segmented data that is a unit of content division in the P2P terminal,
The P2P terminal includes a P2P communication unit that performs P2P communication with other P2P terminals, and an HTTP distribution reproduction unit that receives and reproduces the segmented data.
The HTTP delivery / playback unit transmits a request for information including an acquisition destination URL of segmented data to the viewing start auxiliary server,
Upon receiving the request from the HTTP delivery / playback unit, the viewing start auxiliary server sends a response including a segmented data acquisition URL to the HTTP delivery / playback unit,
The HTTP distribution reproduction unit receives and reproduces the segmented data from the acquisition URL of the segmented data,
The P2P communication unit performs a process of joining a P2P network,
The HTTP delivery / playback unit changes the acquisition source of the segmented data to the P2P communication unit when the participation process to the P2P network by the P2P communication unit is completed. When the participation process to the P2P network is completed, the P2P communication unit starts a request transfer request for requesting the HTTP delivery / playback unit to transfer the request to the viewing start auxiliary server to the P2P communication unit. To the auxiliary server,
Upon receiving the request transfer request from the P2P communication unit, the viewing start auxiliary server transfers the request from the HTTP delivery / playback unit to the P2P communication unit,
When the request is transferred from the viewing start auxiliary server, the P2P communication unit updates the acquisition destination URL of the segmented data to the URL of the P2P communication unit, and sets the acquisition destination URL of the updated segmented data. The content delivery system according to claim 1, wherein a response including the response is transmitted to the HTTP delivery / playback unit.   The said P2P communication part transmits the said request transfer request | requirement to the said viewing-and-listening auxiliary auxiliary server, when the storage number of the segmented data received from the other P2P terminal becomes more than a predetermined regulation value. Content distribution system. A P2P terminal that can participate in a P2P network,
A P2P communication unit that performs P2P communication with other P2P terminals, and an HTTP distribution reproduction unit that receives and reproduces the segmented data;
The HTTP delivery / playback unit transmits a request for information including an acquisition destination URL of the segmented data to the viewing start auxiliary server,
The HTTP delivery / playback unit receives a response including a segmented data acquisition destination URL from the viewing start auxiliary server, receives the segmented data from the segmented data acquisition destination URL, and plays back the segmented data.
The P2P communication unit performs a process of joining a P2P network,
The HTTP delivery reproduction unit is a P2P terminal that changes the acquisition destination of the segmented data to the P2P communication unit when the participation process to the P2P network by the P2P communication unit is completed. When the participation process to the P2P network is completed, the P2P communication unit starts a request transfer request for requesting the HTTP delivery / playback unit to transfer the request to the viewing start auxiliary server to the P2P communication unit. To the auxiliary server,
When the request is transferred from the viewing start auxiliary server, the P2P communication unit updates the acquisition destination URL of the segmented data to the URL of the P2P communication unit, and sets the acquisition destination URL of the updated segmented data. The P2P terminal according to claim 4, wherein a response including the response is transmitted to the HTTP delivery / playback unit.   The said P2P communication part transmits the said request transfer request | requirement to the said viewing-and-listening start auxiliary server, when the storage number of the segmented data received from the other P2P terminal becomes more than predetermined predetermined value. P2P terminal. A viewing start auxiliary server that assists in obtaining segmented data that is a unit of content division in a P2P terminal,
The P2P terminal includes a P2P communication unit that performs P2P communication with other P2P terminals, and an HTTP distribution reproduction unit that receives and reproduces the segmented data.
In response to a request for information including the segmentation data acquisition destination URL from the HTTP distribution reproduction unit, a response including the segmentation data acquisition destination URL is transmitted to the HTTP distribution reproduction unit,
When receiving a request transfer request for transferring the request to the P2P communication unit from the P2P communication unit, the viewing start auxiliary server transfers the request from the HTTP delivery / playback unit to the P2P communication unit. A content distribution method in a content distribution system comprising: a P2P terminal that can participate in a P2P network; and a viewing start auxiliary server that assists in obtaining segmented data that is a unit of content division in the P2P terminal,
The P2P terminal includes a P2P communication unit that performs P2P communication with another P2P terminal, and an HTTP distribution reproduction unit that receives and reproduces the segmented data,
Transmitting a request for information including an acquisition destination URL of segmented data to the viewing start auxiliary server by the HTTP distribution reproduction unit;
When receiving the request from the HTTP delivery / playback unit by the viewing start auxiliary server, transmitting a response including an acquisition destination URL of the segmented data to the HTTP delivery / playback unit;
Receiving and reproducing the segmented data from the acquisition URL of the segmented data by the HTTP delivery / reproducing unit;
Performing a process of joining a P2P network by the P2P communication unit;
When the HTTP delivery / playback unit completes the process of joining the P2P network by the P2P communication unit, the step of changing the acquisition source of the segmented data to the P2P communication unit;
Content delivery method including: