Multicast type contents reception control method and multicast type contents reception client

The present invention particularly relates to a multicast-type content reception control method and a multicast-type content reception client that switch and control content output in a multicast-type content reception client when a plurality of contents to be distributed exist.

Conventionally, in the multicast type content receiving client (hereinafter, may be simply called a client), when there are a plurality of contents delivered from the multicast type content distribution server, arbitrary contents are output on the client. In addition, in order to switch the content to be output at an arbitrary timing, the reception start processing and the reception processing for the delivered content are performed each time the switching is performed. The start processing and end processing of this reception are performed as follows.

A client wishing to receive multicast distribution content first makes it possible to receive information (packets) addressed to the IP multicast address corresponding to the content to be distributed. Specifically, the process of starting the operation of receiving data addressed to the IP multicast address and opening the port of the port number corresponding to the IP multicast address is performed. Next, the client notifies the router that supports multicast in the IP network to which it is connected by the IP multicast address according to IGMP (Internet Group Management Protocol), and sends information (packets) addressed to the IP multicast address. Performs the process of declaring to receive (Join). Then, each router that supports multicast in the IP network by join processing builds a delivery route so that information (packets) addressed to the IP multicast address is forwarded to the client that performed join processing, and then starts forwarding. , Information (packet) addressed to the IP multicast address reaches the client.

Next, when the client terminates the reception of the information (packet) addressed to the IP multicast address, the client cancels the state in which the information (packet) addressed to the IP multicast address can be received. Specifically, the process of ending the operation of receiving data addressed to the IP multicast address and closing the port of the port number corresponding to the IP multicast address is performed. Next, the client declares (Leave) processing to the router in the IP network to which it is connected to end receiving information (packet) addressed to the IP multicast address according to IGMP. Then, the information (packet) addressed to the IP multicast address forwarded by each router in the IP network by the leave process does not reach the client.

In the above method, the port open processing, join processing, close processing, and leave processing for starting and ending reception of the delivered content are performed by the client (that is, the content receiving system side) mainly by the client.

On the other hand, as a method of switching the content to be output on the client from a plurality of contents distributed from the multicast type content distribution server, there is a method of instructing the client from the outside to start and end processing of reception (for example,). See Patent Document 1).

In this method, a client that receives arbitrary content (first content) is identified, and from a communication device other than this client, from the first content to this client via the IP network to which the client is connected. Deliver a request to switch to the second content.

The client that receives the above switching request determines whether or not to accept the request, and when accepting the request, terminates the operation of receiving the information (packet) addressed to the IP multicast address corresponding to the first content and IP. Close the port with the port number corresponding to the multicast address. The client then declares to the routers in the IP network to which it is connected to end receiving information (packets) addressed to that IP multicast address according to IGMP (Leave), and each router in the IP network. The information (packet) addressed to the IP multicast address to be forwarded is not received.

Then, in order to receive the information (packet) addressed to the IP multicast address corresponding to the second content requested to be switched from the communication device other than this client, the reception operation of the information (packet) addressed to the IP multicast address is started. Then, open the port with the port number corresponding to the IP multicast address. The client then declares (Join) that it will receive information (packets) addressed to its IP multicast address according to IGMP to the multicast-enabled router in the connected IP network. Then, each router that supports multicast in the IP network builds a delivery route so that the information (packet) addressed to that IP multicast address is forwarded to the client, and starts forwarding, so that the information addressed to that IP multicast address is forwarded. (Packet) reaches the client.

By the series of operations described above, the content output on the client is switched from the first content to the second content by a communication device other than the client that receives the content.

In addition, the number of routers between the multicast type content distribution server and the client that receives the content in the IP network is defined as the diameter of the network, and the set of IP multicast address and port number corresponding to one content is the multicast channel. Is defined as.

Normally, a client that receives content delivered from a multicast-type content distribution server starts receiving information (packets) addressed to the IP multicast address from the reception process of opening the port with the port number corresponding to the IP multicast address. The time required for the network increases as the diameter of the network increases. This is the number of times control information is exchanged between each router that supports multicast in the IP network and is required to build a delivery route for forwarding information (packets) addressed to that IP multicast address to the client. This is because the amount of route calculation on each router is proportional to the number of routers.<patcit num="1"><text>JP-A-2002-314600</text></patcit>

<p> In the conventional method, there are a plurality of contents distributed from the multicast type content distribution server, and in order to switch the content to be output by the client receiving the content, the IP multicast address corresponding to the output content is to be switched each time. The above-mentioned series of processes is performed.</p><p> Therefore, in the conventional method, there is a problem that there is a time lag in switching the output content in the client that receives the content.</p><p> Therefore, the present invention solves the problem that a time difference occurs when switching the output content in a client that receives the content distributed from the multicast type content distribution server, and the client itself and a communication device other than the client. However, the purpose is to provide a real-time method in which there is no time lag when switching the content output on the client.</p>

<p> In order to solve the above-mentioned problems, in the present invention, a content receiving client that receives a plurality of contents distributed from one or a plurality of multicast type content distribution servers via a network on a plurality of different multicast channels is the content receiving client. In the method of receiving the content according to its own instruction, the content receiving client has a step of acquiring a plurality of multicast channel information corresponding to a plurality of contents in advance, a step of performing a receiving procedure according to the multicast channel information, and a step on the content receiving client. The content receiving client has a step of receiving a request to switch the output content in the above and a step of selecting and outputting the corresponding content from a plurality of contents that have already been received, whereby multiple contents can be viewed on the client. Will be possible.</p><p> Further, when the client and a communication device other than the client request to switch the output content on the client, the client selects and outputs the corresponding content from the plurality of contents already received. This makes it possible to view multiple contents on the client.</p>

<p> As described above, the multicast type content receiving client joins the router corresponding to the multicast in the IP network to which it is connected to the plurality of multicast IP addresses according to IGMP, and receives a plurality of contents in advance. By making it possible, when there is a content switching request from the multicast type receiving client or a communication device other than the multicast type receiving client, the output content can be switched immediately, which occurs in the conventional method. It is possible to prevent time consumption due to switching and the occurrence of harmful effects due to the switching, and it is possible to view a plurality of contents without disturbing images and sounds.</p>

The multicast-type content reception control method according to the first aspect of the present invention is a content reception client that receives a plurality of contents distributed from one or a plurality of multicast-type content distribution servers via a network on a plurality of different multicast channels. However, in the method of receiving the content according to the instruction of the content receiving client itself, the content receiving client has a step of acquiring a plurality of multicast channel information corresponding to the plurality of contents in advance and a step of performing a receiving procedure according to the multicast channel information. , The content receiving client adopts a configuration having a step of receiving a request for switching the output content on the content receiving client and a step of selecting and outputting the content corresponding to the switching request from a plurality of contents already received. In the state where multiple contents can be received in advance, or by receiving and accumulating, when there is a content switching request from the multicast type receiving client or a communication device other than the multicast type receiving client, the output content is immediately output. Can be switched.

The multicast-type content reception control method according to the second aspect of the present invention is a content reception client that receives a plurality of contents distributed from one or a plurality of multicast-type content distribution servers via a network on a plurality of different multicast channels. However, in the method of receiving the content according to the instruction from the communication device other than the content receiving client, the content receiving client obtains a plurality of multicast channel information corresponding to the plurality of contents in advance, and the receiving procedure according to the multicast channel information. The step of receiving the display content switching information from the external communication device, and the step of selecting and outputting the content corresponding to the display content switching information from the plurality of contents already received by the content receiving client. It has a structure, and can be enjoyed like a drama or sports broadcast broadcast on TV by switching the content based on the intention of the content creator or producer, for example.

A third aspect of the present invention is the multicast type content reception control method according to the first aspect or the second aspect, wherein the content selection outputs any one or a plurality of contents. By selecting a plurality of contents to be multicast, it is possible to enjoy a plurality of contents having different appearances.

A fourth aspect of the present invention is characterized in that, in the multicast type content reception control method according to the second aspect, the step of receiving display content switching information from an external communication device receives a plurality of display content switching information. For example, you can enjoy each of the contents created based on the intentions of the creators and producers of multiple contents.

The multicast-type content receiving client according to the fifth aspect of the present invention is a content receiving client that receives a plurality of contents distributed from one or a plurality of multicast-type content distribution servers via a network on a plurality of different multicast channels. Receives a request to switch between a channel information receiving means that acquires a plurality of multicast channel information corresponding to a plurality of contents in advance, a multicast information receiving means that performs a receiving procedure according to the multicast channel information, and an output content on this content receiving client. It has a configuration having a content switching control means and a display content selection processing means for selecting and outputting the content corresponding to the switching request from the plurality of already received contents, and can receive a plurality of contents in advance. By setting the state, when there is a content switching request from the multicast type receiving client or a communication device other than the multicast type receiving client, the output content can be switched immediately.

A sixth aspect of the present invention is characterized in that the multicast type content receiving client according to the fifth aspect further includes a content switching information distribution means for distributing the switching request as display content switching information. By distributing the display content switching information from the client side as well, it is possible to enjoy the content based on the intentions of more people.

The multicast-type content receiving client according to the seventh aspect of the present invention is a content receiving client that receives a plurality of contents distributed from one or a plurality of multicast-type content distribution servers via a network on a plurality of different multicast channels. , A channel information receiving means for acquiring a plurality of multicast channel information corresponding to a plurality of contents in advance, a multicast information receiving means for performing a receiving procedure according to the multicast channel information, and a multicast channel for receiving display content switching information from an external communication device. It has a configuration having an information receiving unit and a display content selection processing means for selecting and outputting content corresponding to the display content switching information from a plurality of already received contents, for example, a content creator or a content creator. It is produced based on the producer's intention, and by switching the content based on that intention, it can be enjoyed like a drama or sports broadcast broadcast on TV.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a block configuration diagram of a multicast type content receiving client according to the first embodiment of the present invention.

In FIG. 1, video input from a plurality of cameras (103-1 to 103-n) is received by the content input unit (104-1 to 104-n) and distributed to different multicast channels by the multicast transmission processing unit 105. Multiplier content distribution server 102, multicast content receiving client 112 that receives multiple contents distributed by the multicast content distribution server 102, and multicast channel information for a plurality of contents distributed from the multicast content distribution server 102 (for example, , Fig. 4) is delivered to the multicast type content receiving client 112. Regarding the content to be displayed on the multicast type content receiving client 112 and the multicast type content receiving client 112, a request to switch the content is delivered to the multicast type content receiving client 112. It consists of a display content switching information distribution device 106. Further, the multicast type content distribution server 102, the multicast type content reception client 112, the multicast channel information distribution device 101, and the display content switching information distribution device 106 are connected to the IP network 107.

Specifically, images from multiple viewpoints (for example, images of soccer games, movies, plays, etc. from multiple viewpoints) taken by multiple shooting cameras installed at multiple points are displayed as different contents via the IP network. It is assumed that the distribution server that distributes the content and the client that receives the contents (operated by the user who views the video) (for example, multicast-type distribution video playback software that operates on a PC). Then, the user displays a video on the client according to his / her taste (for example, a video from a viewpoint in which an interested player is shown in a soccer match video, or a viewpoint video from an interested actor in a movie / stage video). ) To switch and enjoy. In addition, at the instruction request of the video production side (for example, a program producer or a movie director), control information for switching the video displayed on the client is distributed from a communication device other than the client, and the distributed video is effectively distributed by the user. It is also envisioned that they will be viewed by.

Next, the multicast type content distribution server 102 will be described.

The multicast-type content distribution server 102 transmits multi-viewpoint images taken by a plurality of cameras (103-1 to 103-n) installed at multiple points to the content input unit (104-1 to 104-n). input. The content input units (104-1 to 104-n) convert each input video into a video signal format that can be played back by a client (for example, multicast-type distribution video playback software on a PC).

The multicast transmission processing unit 105 divides the video signal from the content input unit (104-1 to 104-n) into packets, and treats each content input unit (104-1 to 104-n) as a plurality of different contents. Deliver to different multicast channels.

Next, the operation of the multicast type content receiving client 112 will be described with reference to the operation flow of FIG.

The multicast channel information receiving unit 113 of the multicast type content receiving client 112 (for example, the multicast type distribution video reproduction software running on the PC) receives a plurality of multicast channel information in which a plurality of contents are distributed by the multicast type content distribution server 102. It is acquired from the multicast channel information distribution device 101 and stored in the multicast channel information storage unit 114 (S201). Figure 3 shows an example of multicast channel information. The multicast channel information 300 includes an IP multicast address 301, a port number 302, and a channel name 303.

Next, the multicast information receiving unit 115 opens (S202) the port of the port number 302 corresponding to one or more IP multicast addresses 301 described in the multicast channel information 300.

Further, the multicast information receiving unit 115 refers to a plurality of IP multicast addresses described in the multicast channel information 300 according to IGMP for the router 108 corresponding to the multicast in the IP network 107 to which the multicast type content receiving client 112 is connected. Join to 301 (S203).

Through these series of processes, in the multicast type content receiving client 112, packets (110-1 to 110-n) destined for a plurality of multicast channels distributed by the multicast type content distribution server 102 in the multicast information receiving unit 115 are sent via the IP network 107. It becomes ready to receive and starts receiving (S204). Each received packet (110-1 to 110-n) is stored in the received content storage unit 125 by the primary storage unit 116 for each multicast channel (S205). The received content storage unit 125 is a primary storage, and when it becomes full, the oldest content is overwritten.

Next, the content switching operation in the multicast type content receiving client 112 will be described.

In order to switch the content displayed on the display unit 123, the user inputs the request from the content switching input unit 120 (for example, a button for channel selection provided in the video playback software), and the information is input. By transmitting the content from the content switching control unit 121 to the display content selection processing unit 124, the content intended by the user is displayed on the display unit 123.

Specifically, for example, as shown in FIG. 3, the content type 304 and the camera viewpoint 305 are described corresponding to each channel 303, and this information is displayed on the display unit 123 so that the user can select the content. To do. Further, the channels may be sequentially selected and the contents may be displayed on the display unit 123. The history of switching by the user may be stored in the content switching information storage unit 117 as the display content switching information 111.

Further, the displayed content or the content different from the content being viewed may be accumulated in the display content storage unit 122 and may not be deleted or overwritten unless instructed.

In addition, the user can display the content stored in the received content storage unit 125 on the display unit 123 at a later date and repeatedly view the content.

In addition, the user can switch the content displayed on the display unit 123 from the content stored in the received content storage unit 125 at a later date according to the switching history stored in the content switching information storage unit 117, and repeatedly view the content. it can.

Further, the multicast type content receiving client 112 receives the display content switching information 111 distributed from the external display content switching information distribution device 105 by the content switching information receiving unit 118, and receives the displayed content switching information 111 by the content switching control unit 121. By transmitting the content to the content selection processing unit 124, the content according to the display content switching information 111 can be displayed on the display unit 123. Further, the content switching control unit 121 stores the received display content switching information 111 in the content switching information storage unit 117.

The display content switching information 111 distributed from the outside is produced based on the intention of the content creator or producer, for example, and is like a drama or sports broadcast broadcast on TV by switching the content based on the intention. You can enjoy it. Further, a plurality of display content switching information 111 may be distributed by a plurality of producers having different viewpoints, and the user may be allowed to select the information 111. As described above, by making multiple contents receivable in advance (because they are received and stored?), Content can be switched from the multicast type receiving client or a communication device other than the multicast type receiving client. When there is a request, it is possible to switch the output content immediately, and it is possible to prevent the time consumption due to the switching that occurred in the conventional method and the adverse effect caused by it, and multiple images and sounds are not disturbed. You can watch the content.

A plurality of multicast type content distribution servers 102 can be configured.

The multicast channel information distribution device 101 and the multicast type content distribution server 102 can be realized on the same device.

The multicast channel information distribution device 101 and the display content switching information distribution device 106 can be realized on the same device.

The multicast type content distribution server 102 and the display content switching information distribution device 106 can be realized on the same device.

The multicast channel information distribution device 101, the multicast type content distribution server 102, and the display content switching information distribution device 106 can be realized on the same device.

The content displayed on the screen 123 can be recorded by the display content storage unit 122.

The display content switching information 111 is distributed from the display content switching information distribution device 106 at the timing of content switching, or is distributed from the display content switching information distribution device 106 as a file describing all the content switching timings and switching requests. Will be done.

As described above, the multicast type content receiving client joins the router corresponding to the multicast in the IP network to which it is connected to the plurality of multicast IP addresses according to IGMP, and receives a plurality of contents in advance. By making it possible, when there is a content switching request from the multicast type receiving client or a communication device other than the multicast type receiving client, the output content can be switched immediately, which occurs in the conventional method. It is possible to prevent time consumption due to switching and the occurrence of harmful effects due to the switching, and it is possible to view a plurality of contents without disturbing images and sounds.

(Embodiment 2) FIG. 4 is a block configuration diagram of a multicast type content distribution system according to the second embodiment of the present invention.

The second embodiment has the same basic configuration as the first embodiment, but allows content switching information to be distributed from the multicast type content receiving client, and the first embodiment. The points that differ from the above will be mainly explained.

In FIG. 4, as in the first embodiment, the multicast type content distribution server 204 that distributes a plurality of contents to different multicast channels, and the multicast type content reception that receives a plurality of contents distributed by the multicast type content distribution server 204. Consists of the multicast channel information distribution device 201 that distributes multicast channel information (for example, shown in FIG. 3) for a plurality of contents distributed from the clients 207 and 218 and the multicast type content distribution server 204 to the multicast type content reception clients 207 and 218. .. Further, the multicast type content distribution server 204, the multicast type content reception clients 207 and 218, and the multicast channel information distribution device 201 are connected to the IP network 206.

The multicast type content receiving clients 207 and 218 acquire the multicast channel information 202 and 203 from the multicast channel information distribution device 201 as in the first embodiment, and distribute the multicast channel information 202 and 203 from the multicast type content distribution server 204 based on the multicast channel information 202 and 203. It is assumed that multiple contents have been received. The procedure is the same as in the first embodiment up to the point where the port is opened, the plurality of IP multicast addresses 301 described in the multicast channel information 300 are joined, and reception is started.

Next, the user of the multicast type content receiving client 207 inputs the request from the content switching input unit 215 in order to switch the content displayed on the display unit 212, and the information is selected from the content switching control unit 214. By transmitting to the processing unit 211, the content intended by the user or the producer is displayed on the display unit 212.

Specifically, for example, as shown in FIG. 3, the content type 304 and the camera viewpoint 305 are described corresponding to each channel 303, and this information is displayed on the display unit 212 so that the user can select the content. To do. The history of switching by the user or the producer is temporarily stored in the content switching control unit 214, and the accumulated history is distributed from the content switching information distribution unit 213 as display content switching information 217. The producer may create and distribute the display content switching information 217, and may distribute it to pre-registered users for free or for a fee.

The display content switching information 217 may be created / distributed by a plurality of producers from their respective viewpoints or based on the intention of the plurality of producers.

On the other hand, in the multicast type content receiving client 218, the content switching information 217 is received by the content switching information receiving unit 219 via the IP network 206.

The content switching information 217 is transmitted from the content switching information receiving unit 219 to the display content selection processing unit 223 via the content switching control unit 220. The display content selection processing unit 223 selects the display content based on the content switching information 217, so that the display unit 225 can view the same content as the display unit 212.

As described above, in the present embodiment, for example, the content (channel) to be viewed based on the intention of a certain user or producer is created as the display content switching information 217, and the content recommended by the user or producer is viewed by distributing the content (channel). Will be possible.

The multicast channel information distribution device 201 and the multicast type content distribution server 204 can be realized on the same device.

As explained above, the content switching information can be distributed from the multicast type content receiving client, and by distributing it as the display content switching information from the client side as well, the content based on the intentions of more people can be enjoyed. be able to.

Further, it has a display content selection processing means for selecting and outputting content corresponding to the display content switching information from a plurality of contents that have already been received, and is produced based on the intention of the content creator or producer, for example. By switching the content based on the intention, it can be enjoyed like a drama or sports broadcast broadcast on TV.

According to the present invention, the multicast type content reception control method enables the output content to be switched immediately when there is a content switching request, and is used in the technical field of viewing a plurality of contents without disturbing images and sounds. Applicable to applications.

<figref num="1">Block configuration diagram of the multicast type content distribution system according to the first embodiment of the present invention</figref><figref num="2">A flowchart for receiving a plurality of contents in the multicast type content receiving client according to the present invention.</figref><figref num="3">The figure which shows the example of the multicast channel information which concerns on this invention.</figref><figref num="4">Block configuration diagram of the multicast type content distribution system according to the second embodiment of the present invention</figref>

Code description

101 multicast channel information distribution device 102 multicast type content distribution server 103 -1, ..., 103-n camera 104 -1, ..., 104-n content input unit 105 multicast transmission processing unit 106 Display content switching information Distribution device 107 IP network 108 multicast-compatible router 109 multicast channel information 110 -1, ..., 110-n content 111 Display content switching information 112 multicast-type content receiving client 113 multicast channel information receiving unit 114 multicast channel information storage unit 115 Multicast information receiving unit 116 Temporary storage unit 117 Content switching information storage unit 118 Content switching information receiving unit 120 Content switching input unit 121 Content switching control unit 122 Displayed content storage unit 123 Display unit 124 Displayed content selection processing unit 125 Received content storage unit 201 Multicast information distribution device 202 multicast channel information 203 multicast channel information 204 multicast content distribution server 205 -1, ..., 205-n content 206 IP network 207 multicast content reception client 208 multicast channel information receiver 209 multicast information reception Part 210 Temporary storage section 211 Display content selection processing section 212 Display section 213 Content switching information distribution section 214 Content switching control section 215 Content switching input section 217 Content switching information 218 multicast type content receiving client 219 Content switching information receiving section 220 Content switching control Part 221 Multiplier information receiving part 222 Temporary storage part 223 Display content selection processing part 224 Multiplier channel information receiving part 225 Display part