CN106817629A - A kind of medium information transmission method, apparatus and system - Google Patents

Abstract

The application relates to the field of communication technology, and discloses a media content transmission method, device and system, which are used to provide a new unicast-multicast conversion form to improve the applicability of the system. The method is as follows: the first BNG receives the multicast join request sent by the second BNG, and the multicast join request is used to request to join the multicast network to receive the information sent by the multicast network; the first BNG sends the multicast join request The multicast join request is converted into a unicast request, and the unicast request is sent to the source server, and the unicast request is used to request media content from the source server; the first BNG receives the source server as a unicast The first media information containing the media content returned in broadcast form, and converting the first media information into second media information containing the media content, and grouping the second media information in the multicast network sent as a broadcast.

Description

A method, device and system for media information transmission

technical field

The present application relates to the field of communication technologies, and in particular to a media information transmission method, device and system.

Background technique

Currently, more and more operators are involved in content operations. Operators purchase sports and entertainment broadcasting rights, and distribute the content to various users (terminals) through their own networks. During the operation process, there are usually some high-profile rebroadcast content, such as football finals, the first broadcast of a new film, etc. At this time, the operator will have a large number of users simultaneously requesting to watch popular videos. Since these users are only temporary users, the operator expects to serve these temporary viewers to obtain additional income, but also does not want to expand capacity because of these temporary users. In this case, the operator adopts multicast mode to bear the hot video, that is, guides the hot media stream from the video source server in unicast mode, and distributes it to each user in multicast mode. In this way, the load of the video source server can be reduced, the traffic of the backbone network can be reduced, and the traffic of the metropolitan area network can be reduced.

However, there are more and more types of terminals for watching popular videos, including mobile phones and other handheld terminals with wireless communication functions. Such terminals often do not support multicast. Therefore, it is necessary to convert the multicast to unicast when approaching such terminals, and send the video to the terminals in unicast form. The process of converting multicast to unicast is generally performed by a broadband network gateway (BNG) close to the terminal.

As shown in Figure 1, in the media stream distribution structure of the prior art, the terminal sends a query request carrying a domain name to a domain name server (Domain NameServer, DNS), and the DNS performs conversion between the domain name and its corresponding Internet Protocol (Internet Protocol, IP) address , and feed back the converted IP address to the terminal. The terminal initiates a HyperText Transfer Protocol (HyperText Transfer Protocol, HTTP) request message based on the Transmission Control Protocol (Transmission Control Protocol, TCP) to the corresponding BNG according to the IP address, requesting the M3U8 index and TS video files. BNG obtains channel information configuration from the policy server, including channel range, channel video source address, channel multicast address, and channel bandwidth. The BNG parses the HTTP request message, maps the channel number carried in the HTTP request message to a multicast address, and requests the multicast stream from the video source server. The video source server sends the multicast stream in multicast form. BNG generates M3U8 index and TS video files from the received multicast stream, and sends them to the terminal in unicast form.

It can be seen that the unicast-multicast conversion form in the prior art requires that the video source server must support multicast, but some video source servers do not necessarily support multicast, for example, the video source server deployed earlier may not necessarily support groupcast. broadcast.

To sum up, the existing media stream distribution architecture and unicast-multicast conversion form lack applicability, and how to design a more applicable media stream distribution architecture becomes a problem.

Contents of the invention

The embodiments of the present application provide a media information transmission method, device and system, which are used to provide a new unicast-multicast conversion form to improve the applicability of the system.

The specific technical scheme that the embodiment of the present application provides is as follows:

In the first aspect, a method for transmitting media content is provided. One BNG is respectively deployed on the side close to the terminal and the side close to the video source server. All multicast protocol interaction and multicast forwarding are only in the network between the two BNGs. Carried on. The video source server can use unicast to send media content to the BNG close to the video source server, which can avoid the limitation caused by the video source server having to support multicast and make the media content transmission system more applicable.

In a possible design, the BNG near the video source server is the first BNG, and the BNG near the terminal is the second BNG. The first BNG receives the multicast join request sent by the second BNG, the multicast join request is used to request to join the multicast network to receive the information sent by the multicast network, and the first BNG sends the multicast join request Convert to a unicast request, and send the unicast request to the video source server, the unicast request is used to request media content from the video source server, and the first BNG receives the video source server to unicast The first media information that contains the media content returned in the form, and converts the first media information into second media information that contains the media content and can be sent in the form of multicast, and the second media information is broadcast in the In the above-mentioned multicast network, it is sent in the form of multicast. The first BNG can replace the video source server to send media information in the form of multicast, and is applicable to the video source server supporting the unicast form. Since the multicast forwarding process is relatively complex and will introduce a large delay, and the video source server and the terminal are both strong computing and weak forwarding devices, they are not good at multicast forwarding. It is completed on a BNG, and the BNG is a strong forwarding device, and the processing efficiency of multicast is higher.

In a possible design, the first BNG converts the multicast join request into a unicast request in the following manner: the first BNG parses the multicast join request to obtain the first payload field , and obtain the first IP address of the video source server; the first BNG generates the unicast request, and the source address of the unicast request is the second IP address and the destination address of the first BNG is the first IP address, and the carried content is the payload field.

In a possible design, the first BNG converts the first media information into second media information that contains the media content and can be sent in a multicast form, and the second media information is broadcast in the multicast In the network, it is sent in the form of multicast, which is realized in the following manner: the first BNG analyzes the first media information to obtain the second load field; the first BNG generates second media information, and the second media information The destination address of the information is the IP address of each receiving node in the multicast network, and the carried content is the second load field; the second media information is sent to each receiving node in multicast form in the multicast network node; wherein, the receiving node includes the second BNG.

In a possible design, before the first BNG receives the first media information including the media content returned by the video source server in unicast form, the first BNG and the video source server perform Security negotiation; after the first BNG receives the first media information containing the media content returned by the video source server in unicast form, if the first media information is encrypted by the video source server, the The first BNG decrypts the encrypted first media information based on the security negotiation result to obtain the media content. The first BNG can send a media content request to the video source server instead of the terminal, and can support encrypted and non-encrypted media content.

In a second aspect, a device for transmitting media content is provided, and the device has a function of realizing terminal behavior in any possible design of the first aspect and the first aspect. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more modules corresponding to the above functions.

In a third aspect, a device for transmitting media content is provided, including a transceiver, a memory, and a processor, wherein the memory is used to store a set of programs, and the processor is used to call the programs stored in the memory to execute the above-mentioned The method described in the first aspect and any possible design of the first aspect.

In a fourth aspect, a computer storage medium is provided for storing a computer program, and the computer program includes instructions for executing the method in the first aspect or any possible implementation manner of the first aspect.

In a fifth aspect, a media content transmission system is provided, including a first BNG and a second BNG, the first BNG is connected to the second BNG, and the first BNG is used to implement the first aspect and the first aspect A method in any possible implementation of . In this way, the limitation caused by the video source server having to support multicast can be avoided, making the media content transmission system more applicable.

Description of drawings

FIG. 1 is a schematic diagram of a media stream distribution architecture in the prior art;

FIG. 2 is a schematic diagram of a media stream distribution architecture in an embodiment of the present application;

FIG. 3 is one of the schematic flow charts of a method for transmitting media content in an embodiment of the present application;

FIG. 4 is the second schematic flow diagram of the method for transmitting media content in the embodiment of the present application;

FIG. 5 is one of the structural schematic diagrams of a transmission device for media content in an embodiment of the present application;

FIG. 6 is a second structural schematic diagram of a device for transmitting media content in an embodiment of the present application.

detailed description

In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings.

In the embodiment of this application, one BNG is respectively deployed on the side close to the terminal and the side close to the video source server, and all multicast protocol interaction and multicast forwarding are only performed on the network between the two BNGs. The video source server can use unicast to send media content to the BNG close to the video source server, which can avoid the limitation caused by the video source server having to support multicast and make the media content transmission system more applicable.

It should be noted that the ordinal numerals such as "first" and "second" mentioned in the embodiment of the present application are used to distinguish multiple objects, and are not used to limit the order of multiple objects.

In the embodiment of the present application, as shown in FIG. 2 , the architecture of media stream distribution includes a terminal 201 , a first BNG 202 , a second BNG 203 and a video source server 204 . Optionally, DNS server 205 and policy server 206 are also included.

Wherein, the terminal is connected to the second BNG203, and is used to send a video request to the second BNG203 to request the required media stream; the terminal is also connected to the DNS server 205, and is used to send a query request carrying a domain name to the DNS server 205 to query the media The address of the flow; the DNS server 205 is used to convert the domain name into a corresponding IP address, and feed it back to the terminal; the second BNG203 is connected to the first BNG202, and is used to realize the interaction of the multicast protocol and the multicast content with the first BNG202 forwarding; the second BNG203 is also connected with the policy server 206, and is used to obtain channel information configuration from the policy server 206; the first BNG102 is also connected with the video source server 204, and is used to send a unicast request to the video source server 204, and will receive The received media content is sent out in the form of multicast; the video source server 204 is used to save and output the media source, for example, it may be a head-end device of an interactive Internet TV.

It should be noted that the application scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute limitations on the technical solutions provided by the embodiments of the present application.

With reference to the network architecture shown in FIG. 2 , the method and device for transmitting media content provided by the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 3 , in the embodiment of the present application, the flow of the method for transmitting media content is as follows.

Step 301: the second BNG sends a multicast join request to the first BNG, and the first BNG receives the multicast join request sent by the second BNG.

Wherein, the multicast join request is used to request to join the multicast network to receive information sent by the multicast network.

Specifically, before the second BNG sends the multicast join request to the first BNG, it receives the media content request sent by the terminal in unicast form, and the media content request is used to request the media content to be played.

In view of the prior art, the request message for the terminal to initiate a media content request to the BNG is a TCP-based HTTP request message. If the request message is encrypted, the BNG cannot parse the message to obtain channel information.

Optionally, in the embodiment of the present application, the request message of the media content request sent by the terminal to the second BNG is based on the User Datagram Protocol (User Datagram Protocol, UDP) format, and the request message in the UDP format does not need to be encrypted to avoid Solved the problem that the second BNG cannot parse the encrypted message. Also, terminal coupling is reduced.

Step 302: the first BNG converts the multicast join request into a unicast request, and sends the unicast request to the video source server, where the unicast request is used to request media content from the video source server.

Since the first BNG is deployed between the second BNG and the video source server in the embodiment of the present application, the multicast join request sent by the second BNG is intercepted by the first BNG and will not be sent to the video source server. After receiving the multicast join request, the first BNG converts the multicast join request into a unicast request, and then sends it to the video source server in unicast form.

The specific conversion method is: the first BNG parses the multicast join request, obtains the first payload field, and obtains the IP address of the video source server, which is recorded as the first IP address here. The first BNG uses the source address as the IP address of the first BNG (referred to as the second IP address here), and the destination address as the first IP address, and performs address encapsulation on the first payload field.

The video source server will receive the unicast request sent from the first BNG, the video source server will analyze the unicast request, obtain the channel number, obtain the media content to be returned to the first BNG, and encapsulate the address of the media content, with the first The IP address is the source address, and the second IP address is the destination address to perform address encapsulation, and the first media information is generated after encapsulation.

Step 303: The video source server returns first media information including media content in unicast to the first BNG, and the first BNG receives the first media information including media content returned by the video source server in unicast.

After the video source server receives the unicast request sent from the first BNG, the video source server parses the unicast request, obtains the channel number, obtains the media content to be returned to the first BNG, and encapsulates the address of the media content, using the first The IP address is the source address, and the second IP address is the destination address to perform address encapsulation, and the first media information is generated after encapsulation.

Based on the fact that the video source server may send encrypted media information, in the embodiment of this application, before the first BNG receives the first media information including media content returned by the video source server in unicast form, the connection between the first BNG and the video source server conduct security consultations;

After the first BNG receives the first media information containing the media content returned by the video source server in unicast form, if the first media information is encrypted by the video source server, then the first BNG, based on the security negotiation result, 1. Decrypt the media information to obtain the media content.

Step 304: The first BNG converts the first media information into second media information that contains media content and can be sent in a multicast format.

Specifically, the first BNG needs to multicast to the second BNG and other receiving nodes in the multicast network. Here, after receiving the first media information, the first BNG needs to change the destination address to correctly Distribute multicast streams. The first BNG parses the first media information and obtains the second payload field. The first BNG generates the second media information. The destination address of the second media information is the IP address of each receiving node in the multicast network, and the source address is still the video The first IP address of the source server, carrying the content as the second payload field.

Step 305: the first BNG sends the second media information in multicast form in the multicast network.

Specifically, the first BNG sends the second media information to each receiving node in a multicast form in the multicast network. Wherein, the receiving node includes the second BNG.

Using the method provided by the embodiment of the present application, the first BNG can replace the terminal to send a media content request to the video source server, and can support encrypted and non-encrypted media content. The first BNG can replace the video source server to send media information in the form of multicast, and is applicable to the video source server supporting the unicast form. Since the multicast forwarding process is relatively complex and will introduce a large delay, and the video source server and the terminal are both strong computing and weak forwarding devices, they are not good at multicast forwarding. The BNG is completed on one BNG, and the BNG is a strong forwarding device, which has higher processing efficiency for the multicast. Therefore, the method in the embodiment of the present application makes the end-to-end performance stronger and the forwarding delay lower.

The method for transmitting media content in the embodiment of the present application will be further described in detail below in combination with specific application scenarios. It is assumed that the first BNG is represented by BNG-1, and the second BNG is represented by BNG-2, and it is assumed that the video source server is an IPTV headend. The terminal wants to request the video stream from the IPTV headend to play. The specific process is shown in Figure 4.

Step 401: The terminal sends a video request to BNG-2 in unicast form.

The video request message is in UDP format, and the video request message carries video source address, channel number and other information.

Step 402: After receiving the unicast video request sent by the terminal, the BNG-2 converts the unicast video request into a multicast join request.

Specifically, BNG-2 obtains channel information from the policy server, and maps the channel number carried in the unicast video request to the multicast destination address in the Protocol Independent Multicast (PIM) network according to the channel information. Recapsulate the video request according to the multicast destination address, change the destination address to the multicast destination address, and generate a multicast join request. The encapsulation address of the multicast join request is different from that of the video request, but the packet content is the same.

Step 403: BNG-2 sends a multicast join request to BNG-1.

Step 404: BNG-1 converts the multicast join request into a unicast request, and sends the unicast request to the IPTV headend.

After BNG-1 receives the multicast join request, it parses the message of the multicast join request, obtains the video source address carried in the message, takes the video source address as the destination address, and the IP address of BNG-1 as the source address, Recapsulate the packet of the multicast join request to obtain the unicast request. The unicast request is an HTTP request.

Step 405: The IPTV headend returns the unicast HTTP video stream to BNG-1 according to the unicast HTTP request.

The IPTV headend can encrypt the HTTP video stream.

Step 406: After receiving the unicast HTTP video stream, BNG-1 parses the payload field in the HTTP video stream, and performs address encapsulation, wherein the encapsulated destination address is the IP address and source address of each multicast receiving node. The address remains unchanged, and a multicast HTTP video stream is generated.

If the HTTP video stream is an encrypted message, BNG-1 and the IPTV head end have completed the security negotiation, therefore, BNG-1 can analyze the encrypted message.

Step 407: forward the encapsulated multicast HTTP video stream in multicast form according to the multicast route.

Step 408: BNG-2 receives the multicast HTTP video stream, parses the payload field, and performs address encapsulation, wherein the encapsulated destination address is the terminal's IP address, the source address remains unchanged, and the encapsulated message is unicast UDP packets in the form of

Step 409: BNG-2 sends the UDP message in unicast form to the terminal.

In this way, after the terminal sends a video request in unicast form, it receives a UDP message returned in unicast form.

In summary, through the introduction of the solutions in the above application scenarios, it can be seen that under this form of network architecture, the dependence on the IPTV headend can be reduced, and the IPTV headend that only supports unicast can also be applied to video streams in this network architecture. distribution, avoiding the requirement that the IPTV headend must support multicast. Since the IPTV headend of the existing network supports unicast as a basic function, the method provided in the embodiment of the present application can be applied to more IPTV headends and has wide applicability.

Due to the deployment of BNG-1, BNG-1 can replace the terminal to initiate a video request to the IPTV headend. If the video content is encrypted, then BNG-2, as the receiving end, has completed the security negotiation with the IPTV headend and can parse the encrypted video. content, and then the parsed content is delivered to BNG-2 through multicast, and BNG-2 is delivered to the terminal through unicast. Therefore, the method in the embodiment of the present application can support encrypted and non-encrypted video streams.

Based on the same inventive concept as the media content transmission method shown in FIG. 3 and FIG. 4, as shown in FIG. and sending unit 503, wherein:

The receiving unit 501 is configured to receive a multicast join request sent by other devices, and the multicast join request is used to request to join the multicast network to receive information sent by the multicast network;

The processing unit 502 is configured to convert the multicast joining request received by the receiving unit 501 into a unicast request, and send the unicast request to the video source server, and the unicast request is used to request media content from the video source server;

The receiving unit 501 is further configured to receive first media information including media content returned by the video source server in unicast form;

The processing unit 502 is further configured to convert the first media information received by the receiving unit 501 into second media information including media content;

The sending unit 503 is configured to send the second media information converted by the processing unit 502 in a multicast form in the multicast network.

Optionally, the processing unit 502 is used for:

Analyzing the multicast join request, obtaining the first payload field, and obtaining the first IP address of the video source server;

Address encapsulation is performed on the first payload field with the source address as the second IP address of the device and the destination address as the first IP address.

Optionally, the processing unit 502 is used for:

Respectively replace the destination address of the first media information with the IP address of each receiving node in the multicast network to generate the second media information;

The sending unit 503 is configured to: send the second media information to each receiving node in the form of multicast in the multicast network;

Wherein, the receiving node includes the second BNG.

Optionally, the processing unit 502 is also used for:

Before receiving the first media information including media content returned by the video source server in unicast form, security negotiation is performed with the video source server; and,

After receiving the first media information containing media content returned by the video source server in unicast form, if the first media information is an encrypted message, the first BNG analyzes the encrypted message based on the security negotiation result to obtain the media content .

Based on the same inventive concept as the media content transmission method shown in FIG. 3 and FIG. 4, as shown in FIG. , memory 603 and bus 604, transceiver 601, processor 602, and memory 603 are all connected to bus 604, wherein a group of programs are stored in memory 603, processor 602 is used to call the program stored in memory 603, when the program is executed , make the processor 602 perform the following operations:

Receive a multicast join request sent by other devices through the transceiver 601, and the multicast join request is used to request to join the multicast network to receive information sent by the multicast network;

Convert the received multicast join request into a unicast request, and send the unicast request to the video source server, where the unicast request is used to request media content from the video source server;

Receive the first media information including the media content returned by the video source server in unicast form through the transceiver 601;

converting the received first media information into second media information containing media content;

The converted second media information is sent in a multicast form in the multicast network.

Optionally, the processor 602 is used for:

Analyzing the multicast join request, obtaining the first payload field, and obtaining the first IP address of the video source server;

Address encapsulation is performed on the first payload field with the source address as the second IP address of the device and the destination address as the first IP address.

Optionally, the processor 602 is used for:

Respectively replace the destination address of the first media information with the IP address of each receiving node in the multicast network to generate the second media information;

Sending the second media information to each receiving node in multicast form in the multicast network through the transceiver 601;

Wherein, the receiving node includes the second BNG.

Optionally, the processor 602 is also used for:

Before receiving the first media information including media content returned by the video source server in unicast form, security negotiation is performed with the video source server; and,

After receiving the first media information containing media content returned by the video source server in unicast form, if the first media information is an encrypted message, the first BNG analyzes the encrypted message based on the security negotiation result to obtain the media content .

The processor 602 may be a central processing unit (central processing unit, CPU), a network processor (network processor, NP) or a combination of CPU and NP.

The processor 602 may further include a hardware chip. The aforementioned hardware chip may be an application-specific integrated circuit (application-specific integrated circuit, ASIC), a programmable logic device (programmable logic device, PLD) or a combination thereof. The aforementioned PLD may be a complex programmable logic device (complex programmable logic device, CPLD), a field-programmable gate array (field-programmable gate array, FPGA), a general array logic (generic array logic, GAL) or any combination thereof.

The memory 603 may include a volatile memory (volatile memory), such as a random-access memory (random-access memory, RAM); the memory 603 may also include a non-volatile memory (non-volatile memory), such as a flash memory (flash memory) ), a hard disk (hard disk drive, HDD) or a solid-state drive (solid-state drive, SSD); the storage 603 may also include a combination of the above types of storage.

It should be noted that the device provided in FIG. 5 can be used to implement the methods shown in FIG. 3 and FIG. 4 . In a specific implementation manner, the processing unit 502 in FIG. 5 may be implemented by the processor 602 in FIG. 6 , and both the receiving unit 501 and the sending unit 603 may be implemented by the transceiver 601 in FIG. 6 .

The present application also provides a media content transmission system, including a first BNG and a second BNG, and the first BNG may be the device provided in the embodiment corresponding to FIG. 5 and FIG. 6 . The media content transmission system is used to execute the method in the embodiment corresponding to FIG. 3 and FIG. 4 .

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

While preferred embodiments of the present application have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be construed to cover the preferred embodiment and all changes and modifications which fall within the scope of the application.

Apparently, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. In this way, if the modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and equivalent technologies, the present application also intends to include these modifications and variations.

Claims (10)

1. a kind of transmission method of media content, it is characterised in that including：

First wideband network gateway BNG receives the multicast addition request that the 2nd BNG sends, and the multicast adds request for asking Multicast network is added to receive the information that the multicast network sends；

Multicast addition request is converted to unitcast request by the first BNG, and the unitcast request is sent into video source Server, the unitcast request is used for the video source server request media content；

First BNG receives the first media comprising the media content that the video source server is returned with unicast fashion Information, and the first media information is converted to comprising the media content and can believed with the second media of multicast form transmission Breath, second media information is sent in the multicast network in multicast form.

2. the method for claim 1, it is characterised in that multicast addition request is converted to list by a BNG Request is broadcast, including：

First BNG adds request to parse the multicast, obtains the first Load field, and obtain the video source First Internet protocol IP address of server；

First BNG generates the unitcast request, and the source address of the unitcast request is the 2nd IP ground of a BNG Location, destination address are first IP address, and carrying content is first Load field.

3. method as claimed in claim 1 or 2, it is characterised in that the first media information is converted to and included by a BNG The media content and the second media information that can be sent in multicast form, by second media information in the multicast Sent in multicast form in network, including：

First BNG is parsed to first media information, obtains the second Load field；

First BNG generates the second media information, and the destination address of second media information is each in the multicast network The IP address of individual receiving node, carrying content is second Load field；

Second media information is sent to each and receives section by the first BNG in the multicast network in multicast form Point；

Wherein, the receiving node includes the 2nd BNG.

4. the method as described in claim 1,2 or 3, it is characterised in that a BNG receive the video source server with Before the first media information comprising the media content that unicast fashion is returned, also include：

Security negotiation is carried out between first BNG and the video source server；

First BNG receives the first media comprising the media content that the video source server is returned with unicast fashion After information, also include：

If first media information is based on the security negotiation knot by the video source server for encrypting, a BNG Really, first media information being encrypted is decrypted.

5. a kind of transmitting device of media content, it is characterised in that including：

Receiving unit, the multicast for receiving the transmission of other devices adds request, and the multicast adds request for asking to add Multicast network is receiving the information that the multicast network sends；

Processing unit, adds request to be converted to unitcast request for the multicast that receives the receiving unit, and by institute State unitcast request and be sent to video source server, the unitcast request is used for the video source server request media content；

The receiving unit, be additionally operable to receive the video source server with unicast fashion return comprising the media content First media information；

The processing unit, the first media information for being additionally operable to receive the receiving unit is converted to comprising in the media The second media information that hold and can be sent in multicast form；

Transmitting element, for second media information of changing the processing unit in the multicast network with multicast shape Formula sends.

6. device as claimed in claim 5, it is characterised in that the processing unit is used for：

Add request to parse the multicast, obtain the first Load field, and obtain the video source server the One Internet protocol IP address；

Generate the unitcast request, the source address of the unitcast request is that second IP address of a BNG, destination address are First IP address, carrying content is first Load field.

7. the device as described in claim 5 or 6, it is characterised in that the processing unit is used for：

First media information is parsed, the second Load field is obtained；

The second media information is generated, the destination address of second media information is each receiving node in the multicast network IP address, carrying content is second Load field；

The transmitting element is used for：Second media information is sent into each in multicast form in the multicast network to connect Receive node；

Wherein, the receiving node includes the 2nd BNG.

8. the device as described in claim 5,6 or 7, it is characterised in that the processing unit is additionally operable to：

Before the first media information comprising the media content that the video source server is returned with unicast fashion is received, Security negotiation is carried out between the video source server；And,

After the first media information comprising the media content that the video source server is returned with unicast fashion is received, If first media information is by the video source server for encrypting, based on the security negotiation result, to the institute being encrypted State the decryption of the first media information.

9. a kind of transmitting device of media content, it is characterised in that including transceiver, processor, memory and bus, transmitting-receiving Device, processor, memory are connected with bus, wherein, batch processing is stored in the memory, the processor is used to call The program stored in the memory, when program is performed so that the computing device such as any one of claim 1-4 institute The method stated.

10. a kind of Transmission system of media content, it is characterised in that including the first wideband network gateway BNG and the 2nd BNG, institute State a BNG to be connected with the 2nd BNG, a BNG is used to perform the method as described in claim any one of 1-4.