CN115174998A

CN115174998A - Future network-based broadcast system of real 4K home theater broadband metropolitan area network

Info

Publication number: CN115174998A
Application number: CN202210572629.8A
Authority: CN
Inventors: 楼培德; 赵思行; 艾博; 谢明芹; 陈光琳; 张晓薇; 梁峰; 谢建平
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-10-11

Abstract

The application relates to a future network-based broadcast system of a real 4K home theater broadband metropolitan area network, which comprises the following steps: a national backbone network is constructed from the distribution management control module to the transfer modules located in various provinces and cities in China based on a future network IPV9, networking is also carried out from the transfer modules to the household metropolitan area network broadcasting modules in the provinces based on the future network, and networking is also carried out between the core routing unit and the broadcasting unit in the household metropolitan area network broadcasting modules based on the future network. The system can carry out national networking based on a future network, can meet the requirements of stability, safety and rapidness of ultra-large file transmission, provides massive V9IP addresses compatible with V4 and strong capability and equipment of the future network for spanning and covering a heterogeneous network, greatly reduces the information transmission cost of the whole system, particularly can fully utilize rich bandwidth and server resources of nodes in the heterogeneous V4vpn network, and realizes the transmission characteristics of good use, high speed, low price and safety of the heterogeneous networking of the future network; the transmission rate can reach 50M-100M, and the bandwidth can reach 100M-1000M.

Description

Future network-based broadcast system of real 4K home theater broadband metropolitan area network

Technical Field

The invention relates to the technical field of network on-demand, in particular to a real 4K home theater broadband metropolitan area network on-demand system based on a future network.

Background

Currently, with the rapid development of communication technologies and the improvement of living standards of people, emerging services such as internet of things (IoT), virtual Reality (VR), ultra-high definition video and the like are continuously emerging and start to gradually enter the daily life of people, and therefore, people have more entertainment options, and watching 4K video films at home has become the trend of people. But the current network environment with the crowded and unstable public network of the internet cannot guarantee the requirement of the real 4K video on the network transmission condition.

In recent years, the design and implementation difficulties of video distribution systems are: firstly, the volume of a video copy file is large, and the size of a digital release video package is 200 GB-400 GB and even can reach about 500 GB; secondly, to realize synchronous high-speed distribution from the Beijing distribution center to nodes at all levels of the whole country, if a traditional C/S architecture is adopted, huge bandwidth and hardware resources are needed, so that the factors such as network bandwidth, hardware cost, transmission speed and reliability need to be comprehensively considered in system design. By adopting a novel cloud network scheme, the transmission of the super-large files is still difficult to get rid of the difficult situation that the three elements of the current v4 internet transmission, namely the three elements, namely the good use, the high speed and the low price, can only occupy the two elements simultaneously.

Disclosure of Invention

The embodiment of the application provides a future network-based broadcast system of a real 4K home theater broadband metropolitan area network. The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

In a first aspect, an embodiment of the present application provides a future network-based on-demand system for a real 4K home theater broadband metropolitan area network, where the system includes:

the original video file storage module is used for storing original audio and video files;

the distribution management control module is used for converting the original audio and video files into DASH files and transmitting the DASH files to the transfer module;

the transfer module is used for receiving the DASH file transmitted by the distribution management control module, transmitting the DASH file to a home metropolitan area network multicast module, and receiving feedback information transmitted by the home metropolitan area network multicast module, and transmitting the feedback information to the distribution management control module;

the metropolitan area of family broadcasts the module, including:

the core routing unit is used for receiving the DASH file transmitted by the transfer module and sending the DASH file to an on-demand unit;

the on-demand unit is used for receiving and downloading the DASH file and transmitting feedback information of the DASH file after downloading to the transfer module through the core routing unit;

the original video file storage module, the distribution management control module, the transfer module, the core routing unit and the on-demand unit are networked through a future network.

Optionally, the distribution management control module includes: an encoding unit and a dividing unit;

the encoding unit is used for encoding the original audio and video file and acquiring the encoded original audio and video file;

the segmentation unit is configured to slice the encoded original audio/video file to generate the DASH file.

Optionally, the distribution management control module is configured to customize file configuration based on an open source DASH, and obtain the DASH file in the form of an executable file.

Optionally, the transit module is configured to set up a streaming server, and perform cross-domain control between the distribution management control module and the home metropolitan area network multicast module through the streaming server.

Optionally, the on-demand unit includes: the system comprises a streaming media control subunit, an HTTP access subunit, an analysis subunit and a video playing subunit;

the analysis subunit is configured to analyze the DASH file to obtain analysis information;

the HTTP access subunit is used for receiving the analysis information, obtaining a video segmentation file corresponding to the analysis information, and transmitting the video segmentation file to the video playing subunit;

the video playing subunit is configured to play the received video segment file;

and the streaming media control subunit is used for controlling the transmission among the analysis subunit, the HTTP access subunit and the video playing subunit.

Optionally, the on-demand unit includes: the code logic compiling subunit and the webpage compiling subunit;

the code logic compiling subunit is used for establishing the code logic of the javascript file and carrying out corresponding modification;

and the webpage compiling subunit is used for compiling an HTML5 webpage file.

Optionally, the on-demand unit is provided with an adaptive code rate algorithm and a buffer cache policy.

Optionally, the buffer caching policy is set with caching parameters initialBufferLevel, bufferpuning interval, and bufferToKeep.

Optionally, the buffer caching policy includes an LSTM neural network model; the buffer cache strategy is used for adaptively adjusting cache parameters initialBufferLevel, bufferpuning Interval and buffertoKeep through the LSTM neural network model.

Optionally, the future network comprises an IPV9 network.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

in the embodiment of the application, the future-network-based broadcast-on-demand system for the real 4K home theater broadband metropolitan area network constructs a national backbone network based on future network IPV9 from the distribution management control module to the transfer modules located in various provinces throughout the country, performs networking based on the future network from the transfer module to the intra-province home metropolitan area network broadcasting module, and performs networking based on the future network between the core routing unit and the broadcast-on-demand unit inside the home metropolitan area network broadcasting module. By networking based on a future network, the requirements of stability, safety and rapidness of transmission of larger original audio and video files can be met, massive V9IP addresses compatible with V4 and strong ability and equipment spanning a heterogeneous network of the future network are provided, the information transmission cost of the whole system can be greatly reduced, and particularly, rich bandwidth and server resources of nodes in the heterogeneous V4vpn network can be fully utilized; the transmission rate can reach 50M-100M, and the bandwidth can reach 100M-1000M.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic structural diagram of a future-network-based broadcast system for a broadband metropolitan area network of a real 4K home theater according to an embodiment of the present application;

fig. 2 is a schematic diagram of a CORS communication process of a future network-based real 4K home theater broadband metropolitan area network on-demand system according to an embodiment of the present application;

fig. 3 is a schematic diagram of a cache parameter setting process of a future-network-based broadcast system of a broadband metropolitan area network for a real 4K home theater according to an embodiment of the present application.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them.

It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of systems and methods consistent with certain aspects of the invention, as detailed in the appended claims.

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the application, the IPV9 network is a future network, based on decimal digital codes, adopts a zero trust security mechanism of communication after verification and is compatible with the current Internet system, and the problem of network transmission bottleneck is solved by combining an IPV9 backbone network and an operator metropolitan area network.

DASH is a streaming media transmission technology based on HTTP protocol, which decomposes an original audio/video file into a series of small file segments (i.e. video segment files of the present application) at a server (i.e. a distribution management control module of the present application), where each segment only contains playable content with a very short length, and the total length of the original audio/video may be as long as several hours. The client can adaptively select the audio and video quality by benefiting from the characteristic of DASH technology multi-rate slicing, and avoids playing pause and repeated cache under certain conditions, which has important significance in high-rate audio and video transmission. Therefore, the DASH technology is deployed in the server of the server and used for processing the audio and video.

The Nginx is a lightweight web server, has the characteristics of less occupied memory, strong concurrency capability and high configuration freedom, is a mainstream server file management system, and simultaneously supports the networking functions of a reverse proxy and a CDN.

Js is an open source dibbler, is specially designed for DASH format media, is developed at the front end on the basis of sufficiently analyzing experimental requirements, is designed into a special audio and video dibbler suitable for the application, realizes the playing of DASH files at a client, and can be installed in a Ubuntu and Windows operating system to test the stability of the dibbler.

Referring to fig. 1-3, schematic diagrams of a future-network-based live 4K home theater broadband metropolitan area network on-demand system are provided for the embodiments of the present application. As shown in fig. 1-3, a system of an embodiment of the present application may include: the system comprises an original video file storage module, a distribution management control module, a transfer module and a home metropolitan area network broadcasting module.

The original video file storage module is used for storing original audio and video files; the method can be an audio and video file storage server which is mainly used for storing original audio and video files, and in one embodiment, the original audio and video files are audio and video files to be requested.

The distribution management control module is used for converting the original audio and video files into DASH files and transmitting the DASH files to the transfer module; the distribution management control module is a control center for the whole audio and video transmission and distribution. The distribution management control module can be used as a distribution center management server of the application, and processes the audio and video files through a DASH technology, and the specific process comprises the following steps: an encoding unit and a partitioning unit.

The encoding unit is used for encoding the original audio and video file and acquiring the encoded original audio and video file; the segmentation unit is configured to slice the encoded original audio/video file to generate the DASH file.

In the encoding unit, the original audio/video file is encoded in different qualities by a DASH generator, a plurality of MP4 or h.264 files with different code rates and different definitions are generated after traversing and combining, then the content of the MP4 or h.264 file is divided into smaller file sequence segments by a dividing unit and stored in the same directory, and a Media Presentation description file recording audio/video segment information is generated at the same time, namely an MPD file. The MP4 or h.264 file may be the original audio-video file after encoding, and the media presentation description file may be a DASH file.

The media presentation description file has a hierarchical structure, and the application analyzes the recorded audio and video segmentation information and summarizes the segmentation mode of the DASH technology as follows:

(1) The largest unit of DASH segments is segments (Period), each Period containing consecutive audio-video segments at different resolutions.

(2) The second level unit of DASH segments is adaptation Set (adaptation Set), each containing audio or video segments at the same resolution.

(3) The third level unit of the DASH segment is description information (reproduction), which describes information such as resolution, code rate, and encoding mode of the audio/video segment.

(4) The minimum unit of the DASH Segment is a Segment (Segment), each Segment is an audio/video Segment with parameters such as resolution, code rate, encoding mode, etc., and each Segment has a corresponding Uniform Resource Locator (URL), and the Segment is a final parsing target during audio/video playing.

Because the media presentation description file uses Extensible Markup Language (XML), interaction can be performed between incompatible systems, and thus the audio/video file processed by the DASH technology has good compatibility.

In one embodiment, a first scheme for processing an original audio/video file by a DASH technology is as follows: processing the original audio and video file by adopting an FFmpeg + Bento4 combined mode, taking charge of the encoding of the original audio and video through FFmpeg in an encoding unit, taking charge of the slicing of the audio and video file through Bento4 in a segmentation unit, and obtaining the DASH file.

Generating a DASH file using the FFmpeg + Bento4 combination requires editing parameters in the form of command lines, and can simplify operations by editing python scripts on an Ubuntu system, and edit bat scripts on a Windows system.

The FFmpeg is a set of open source programs for recording and converting audio and video, and has powerful functions and more parameters. The command line parameters that need to be used in the present application are shown in the following table:

table 1 ffmpeg command line parameters

Based on the command line, the FFmpeg can process audio and video resources with different resolutions and different code rates.

Bento4 is a C + + class library and tool set designed for reading and writing ISO-MP4 files, and supports ISO-MP4 to MPEG2-TS conversion, parsing and multiplexing of H.264/H.265 elementary streams, content encryption and decryption and the like.

The Bento4 SDK developer suite contains a wide variety of tools, with common tool names and their functions as shown in table 2.

TABLE 2 common tools and their function of Bento4

Name(s)	Function(s)
		mp4info	Displaying file high-level information
mp4encrypt	Encrypted MP4 file
		mp4decrypt	Decrypting MP4 files
mp4fragment	Creating fragmented files from non-fragmented files
		mp4mux	Multiplexing one or more elementary streams into mp4 files
mp4dash	Creating MPEG DASH output streams from one or more MP4 files
		mp4aac	Extraction of original aac elementary stream from MP4
mp42ts	Converting mp4 files to MPEG2-TS files

The DASH file is made by using the mp4fragment and the mp4DASH tool, as shown in the above table 2, the mp4fragment is used for fragmenting the audio and video, and the DASH file is created by the mp4DASH according to the fragmented audio and video. Inputting the path where the file processed by the ffmpeg is located and the related command into the mp4fragment, taking processing of audio and video with 4K resolution as an example, the command lines needing to be input are sequentially as follows:

(1)fragment-duration 4000/4khdr_1080.mp4 4khdrvideo_2160+.mp4

(2)mp4dash 4khdrvideo_2160+.mp4-o4khdr_dash

wherein duration4000 represents an interval time of 4 seconds. Since both the 3840x2160 and 4096x2160 resolutions are referred to as 4K resolutions, and the latter code rates are higher in the present application, the present application names 4096x2160 as 4K + in the command line.

And after the operation is finished, obtaining an audio and video slice file and a DASH file containing slice information of the audio and video slice file, wherein the audio file and the video file are mutually independent and are independently stored, and each audio and video folder contains an initialization file of the content.

Because the test Video duration is short, the DASH file only contains one Period, the time Period contains two Adaptation sets, namely Video and Audio, and if the time Period contains information of different languages, the time Period can be further divided into a plurality of Adaptation sets, and for the Audio and Video used in the application, four types of repetition exist in the Video subset, namely: 4096x2160 non-blood induction 35Mbps, 3840x2160 non-blood induction 25Mbps, 2048x1024 non-blood induction 10Mbps and 1920x1080 non-blood induction 5Mbp Audio, and two descriptions are in the subset, namely: 128K Y44100hz and 192K Y44100hz. The application finishes the DASH slicing processing of the audio and video.

In an embodiment, the distribution management control module is configured to obtain the DASH file in the form of an executable file based on an open source DASH, a custom file configuration.

Dash is an open source project on GitHub, which is constructed based on FFmpeg tool in the same way as the first solution, but is different from the first solution in that the project uses MP4Box tool to perform original audio/video slicing operation, and the configuration input mode and the obtained media presentation description file are different. The DASHEncoder also supports MySQL database operation, so the method is suitable for large engineering projects.

The programming language of the DASH entry is C + +, the entry suffix is. Conf configuration file is used to obtain entry parameters, the file needs to perform parameter analysis in the entry master file, taking a test file named paris christmas.mp4 as an example, the test file is manufactured into DASH file with two resolutions of 4k speech recognized 15mbps and 2k speech recognized 10mbps, the interval duration is 2s, and the configuration details need to be entered are:

#＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝General Options＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

dest-directory：./source/

video-encoder：H264

audio-encoder：AAC

multiplexer：mp4box

#＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝Video Options＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

input：ParisChrismas.mp4

input-width：3840

input-height：2160

video-rep：10240@2048x1024|15360@3840x2160

fps：25

profile：high

preset：fast

passes：1

video-codec：libx264

#＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝Audio Options＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

audio-rep：2，44100，128|2，44100，192

audio-input：wonder.mkv

audio-codec：libvo_aacenc

#＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝MP4Box Options＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

mux-combi：10240@128|10240@192|15360@128|15360@192

#＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝MPD Options＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

rap-aligned：1

use-template-url：0

mpd-name：wonder

base-url：0

fragment-size：2000

segment-size：2000

minBufferTime：2000

the main file name of the dash project is dash. Cpp, and since the project mainly calls existing libraries and tools in the main file, the application mainly analyzes the main function implementation. The DASHEncoder cpp file is mainly associated with an anyOption cpp, a h264Encoder cpp and an MPDGener cpp file, wherein the anyOption is responsible for analyzing and setting related parameters, the h264Encoder is responsible for calling ffmpeg to finish audio-video conversion, and the MPDGener is responsible for calling an MP4Box slice and generating an MPD file. Because the project source code lacks maintenance, errors which cannot be compiled through occur, wherein two typical errors are as follows:

(1) The encode _ factor pointer is not created before the parse () function call.

(2) The video _ encoder _ type variable should be created after the pares () function is called.

And (3) obtaining pseudo code logic of the project file after the error is changed, namely DASHEncoder processing logic as follows:

1.int main(intargc,char*argv[])：

2. defining an anyOption pointer opt; an EncodeFactory pointer encodery;

3.int res＝parse(opt,argc,argv)

4.if(res

5.If file format is not supported:

6. throwing out an exception: unsupported file formats

MPD calling function acquisition configuration list parameter

8. Define MP4Box pointer muxer

9. Invoking transvideo () for video conversion

10. Calling Transaudio () for audio conversion

11. Calling avmux () for audio-video multiplexing

12. Calling mpdgen () to generate MPD file

13. Return result 0

Int pars (anyOption opt, intargc, char argv [ ]) { resolution parameter }

Inttransvideo (file parameter) { video conversion }

16. intraaudio (file parameter) { Audio conversion }

Intavmux (audio file, video file) { audio-video multiplexing }

Intmpedggen (MPD generator, output path) { output MPD file }

After running the solution and generating the executable file using the visual studio, dashencoder.

Wherein, the content of the MPD file is as follows:

as can be seen from the above, the processing manner of the video in the present scheme is different from that in the first scheme in that:

(1) The slicing mode is different. The DASHEncoder does not slice the audio and video files independently, but separates original audio and video resources with different qualities by using ffmpeg, then uses the MP4Box to traverse and multiplex the separated audio and video files to generate complete audio and video files, and finally slices the audio and video files;

(2) The MPD file recording information is different. The segment section identifies in detail the correspondence of the slice to the time, and the URL to which the segment corresponds is displayed under each entry. So far, the application successfully uses two ways to obtain the DASH file, and the realization of DASH at the server end is completed.

And the transfer module is used for receiving the DASH file transmitted by the distribution management control module, transmitting the DASH file to the home metropolitan area network multicast module, and receiving feedback information transmitted by the home metropolitan area network multicast module, and transmitting the feedback information to the distribution management control module.

In the embodiment of the present application, the relay module is only used as a relay node for DASH file transmission, and the relay module may be used as a relay server for DASH file transmission; the transfer module comprises: the system comprises a first-level transfer unit and a second-level transfer unit, wherein the first-level transfer unit can be used as a first-level transfer server for DASH file transmission, and the second-level transfer unit can be used as a second-level transfer server for DASH file transmission; the first-level relay server may be a data center in Jiangsu, and correspondingly, the second-level relay server may be a data center in Suzhou or a data center without tin.

In an embodiment, the transit module is configured to set up a streaming media server, and perform cross-domain control between the distribution management control module and the home metropolitan area network multicast module through the streaming media server. A streaming server may be built using nginnx.

Considering the storage and management problem of the film source, the application downloads the version 1.2 which can run in the Windows environment from the Nginx official network. Nginx is highly easy to use because the main task of the user is to configure Nginx. Conf files located under the conf folder. The configuration file is automatically loaded when the Nginx service is operated for the first time, and the Nginx-srreload command can be operated in the command line window after the configuration items are changed. The Nginx profile consists of 6 sections, the function of which is shown in table 3.

Nginx Module function Table

Module name	Function(s)
		main	Configuring nginx global information
events	Configuring nginx mode of operation
		http	Configuring http protocol information
server	Configuring streaming media server access information
		location	Configuring access routes
upstream	Configuration load balancing

The content to be configured is located in event, http, server and location modules, the port occupation condition of the current host is checked first before configuration is performed, then an unoccupied port is used as a process port, other configuration items further include addresses and port numbers of a streaming media server, the maximum connection number, a root file directory, a file reading request and the like, and after configuration is completed, pseudo codes of a conf file (namely an algorithm of the streaming media server configuration module) are as follows:

1.Event setting the maximum connection number of working process to 1024

Http-importing a mapping table of file extension and file type

3. Set the maximum file transfer size to 5120m

4. Opening the transmission of files in sendfile mode

5.server setting the monitor port 910

6. The server name is set to 192.168.3.64

Location setting D disk as root

8. Allowing all access under a path

9. Turning on autoindex, autoindex _ exact _ size, autoindex _ localtime

Location/set setting folder path for automatic jump access

It should be noted that the configuration file should be edited by using a visual studio code or other professional application, and if the configuration file is modified by using a text editor, a messy code problem may occur, resulting in a failed start-up of the streaming server process. After editing and storing the parameters, inputting start nginx in a command line to start service, inputting URL (Uniform resource locator) http:// localhost:910 in an address column of a browser, returning, and if a welcome interface is displayed, proving that the service is successfully started, and if the application is a test in an intranet, inputting http://192.168.3.64 in the address column of the browser of another device under the same local area network to obtain a file list obtained by accessing a streaming media server.

Clicking one file in the file list obtained by accessing the streaming media server, and automatically popping up a downloading page by the browser, wherein the situation shows that the streaming media server is successfully built.

Before the cross-domain problem between the distribution management control module and the home metropolitan area network broadcasting module is solved, the homologous strategy of the browser is known.

The same-source policy is an important security policy proposed by Netscape, which is used for limiting the interaction between an origin document or a script loaded by the origin document and another access source, and is one of the security policies that all browsers conform to at present. The specific meanings are as follows: two URLs are called homologous if the protocols, port numbers, and host used by the two URLs are the same, and are called non-homologous otherwise. The information contained by the URL is also referred to as source information. Resource interaction between different sources is constrained by a source policy, and the constrained behaviors include: the method comprises the following steps of cross-domain write operation, cross-domain resource embedding and cross-domain read operation, wherein the read operation is generally not allowed, but is also mainly used in the resource access process of the application. Under the condition of no configuration, the problem that the DASH player manufactured by the present application is used to request DASH resources stored on a streaming media server, and the error information obtained by the browser console refers to that the resources are prohibited by the cor policy, obviously, the constraint of the cor policy is a direct reason for the failure of resource request, so the present application will continue to research the cor policy.

The CORS policy is known as Cross-Domain resource sharing (CORS), a W3C standard that allows JavaScript running on a browser to issue an XMLHttpRequest request to a Cross-source server for exchanging data in the background. The CORS strategy overcomes the limitation that Ajax can only be used in a same source mode, the application is wide, the current mainstream browser supports CORS communication, and cross-source communication can be achieved if a streaming media server realizes a CORS interface. The CORS strategy is based on an HTTP message header, the browser divides CORS requests into simple requests and non-simple requests, the requests belong to the simple requests as long as the request method is one of HEAD/GET/POST, HTTP header information is limited to several fields of Accept/Accept-Language/Content-Language/LastEvent-ID/center-Type, and the requests sent by the method belong to the simple requests.

The process of CORS communication is shown in FIG. 2.

In order to avoid unexpected influence of the cross-domain request on the user data of the distribution center management server, in the actual communication process, the browser needs to initiate a pre-check request by using an OPTIONS method to obtain whether the streaming media server allows cross-domain, only after the streaming media server is determined to allow cross-domain, the requester can formally initiate a cor simple request, an Origin field is added in the header of a request message to explain the source information of the request, the streaming media server determines whether to approve the request according to the analyzed source information, and if so, the streaming media server returns a response message, and newly added fields in the response message are listed in table 4.

Table 4. Agree with the new field added in the cross-domain request response message

If the source information contained in the request message is not in the allowable range, the streaming media server will also return a normal HTTP message, but does not contain an Access-Control-allocation-Origin field, and the browser will throw out the error information obtained by the browser console mentioned above after parsing.

In summary, the reason why the browser is denied access to the resource has been found, and it is easy to see from analysis that the cross-domain problem should be solved at the backend by modifying the cross-domain request permission information, so the cross-domain problem solution obtained by the present application is: relevant fields are added in a local module of the Nginx configuration file, and a list of the added fields (namely, an algorithm of cross-domain configuration) is as follows:

1.add_header Access-Control-Allow-Origin*；

2.add_header Access-Control-Allow-Methods'GET,POST,OPTIONS'；

3.add_headerAccess-Control-Allow-Headers'DNT,X-Mx-ReqToken,Keep-Alive'；

4.add_headerAccess-Control-Allow-Headers’Range’；

wherein, the first row represents that all cross-domain request sources are accepted, and the item needs to be limited during actual deployment because the item is used by experiments. The second row indicates acceptance of the OPTIONS preview request and the third row indicates addition of a new content format support type by the streaming server. In addition, the present application adds permission for the Range field in the fourth row: the Range request allows a manager to send only a part of the HTTP message to the client from the streaming media server, resource waste is avoided, the request mode is suitable for downloading files with interruption and recovery functions and transmission of large media, and the Range request has important significance for transmitting high-bit-rate audio and video and therefore must be added. After the configuration file is reloaded, the streaming media server resource is requested again, and the player successfully acquires and plays the streaming media resource stored on the streaming media server.

Therefore, the streaming media server is successfully built by using Nginx, the cross-domain problem is solved, and audio and video playing based on URL address resolution of the streaming media server is realized.

The metropolitan area of family broadcasts the module, including:

the core routing unit is used for receiving the DASH file transmitted by the transfer module and sending the DASH file to an on-demand unit; the core routing unit may act as a router for the core layer.

The on-demand unit is used for receiving and downloading the DASH file and transmitting feedback information of the DASH file after downloading to the transfer module through the core routing unit; the on-demand unit can be used as an on-demand player of the client.

In the on-demand unit, the client may implement playing of DASH resources through DASH technology.

Firstly, the purpose of DASH resource segmentation transmission is to effectively reduce the pause phenomenon in the streaming media playing process, so that a player supporting segmentation transmission needs to be designed at a client, the player also needs to have the function of adjusting the audio and video quality, and meanwhile, the process of switching the audio and video quality by a user according to the network condition of the user needs to be perceptive-free and the audio and video playing needs to be in seamless connection. In the on-demand unit, the process of the client requesting DASH resources includes: the system comprises a streaming media control subunit, an HTTP access subunit, an analysis subunit and a video playing subunit;

the analysis subunit is configured to analyze the DASH file to obtain analysis information; the parsing information includes segment information and a corresponding URL address of the DASH streaming media.

In the embodiment of the application, a client represented by an on-demand unit and a distribution center management server represented by a distribution management control module transmit a DASH file by using an HTTP protocol through a transfer module, when the client requests a DASH resource, the client first acquires the DASH file, analyzes the DASH file by an analysis subunit to obtain segment information of a DASH streaming media and a corresponding URL address, then transmits the analyzed information to an HTTP access subunit, the HTTP access subunit receives an audio/video segment file corresponding to the URL address in the segment information of the DASH streaming media, and finally transmits the audio/video segment file to a video playing subunit for playing. The DASH player is designed according to the transmission logic of the on-demand unit and the distribution management control module; the DASH technology is deployed in an on-demand system, so that audio and video watched by users can be smoother, content providers can add multiple audio tracks and multiple video tracks more conveniently, and more flexible and diversified content services are provided for different user groups.

Js is an open source audio and video player project developed according to a DASH protocol established in the industry, and is constructed based on a javascript library named Grunt.

Js should be presented in the form of HTML5 web page, so the process of developing on-demand unit in the present application at the client includes: the code logic compiling subunit and the webpage compiling subunit; the code logic compiling subunit is used for establishing the code logic of the javascript file and carrying out corresponding modification, and is expected to mainly work in a dash.

The dash.all.debug.js file used in the present application is a DASH player script having sixty thousand lines of codes, in which functions suitable for various scenes are built and other script files are associated, and the functions and functions used in the present application are listed in table 5.

Table 5.Dash.all.debug.js script function and function

Name(s)	Function(s)
		MediaPlayer()	Specifying a dash object
create()	Creating a dash object
		initialize(view,source,Autoplay)	Initializing basic parameters
updateSetting(…)	Updating advanced parameters
		getActiveStream()	Obtaining a current play stream
getDashMetrics()	Obtain the dash space
		getDashAdapter()	Obtaining dash adapter

In table 5, the source parameter of the initialize function is responsible for entering the URL, since the URL used in the present application is a streaming server URL, the parsing process is modified, and the modified parsing logic pseudo code (i.e. the algorithm for creating the player) is as follows:

1.source＝get(URL)

if source resource exists:

attatcchsource (afferent source):

if player is not initialized:

throw uninitialized exception

If source type = string:

7. load URIFragmentModel

8.initialize(source)：

9. Resolving to obtain parameters

10. Returning the parsed source

11. Execution _ initializepfeed ():

12. js load Manifest Lored

13.loader(source)：

14. Changing the parsing mode to parsing nginx URL format

And the webpage compiling subunit is used for compiling an HTML5 webpage file, inserting a related script and realizing the front end of the player. The web page is written to include two parts of content, which are: 1. writing a script part function; 2. and performing page design by using the CSS file. The script part function pseudo code (i.e. the algorithm of the player parameter script function) is now listed as follows:

function dash (key identification):

2. defining the layer, controllbar, url, video, eventPoller

3.player.initialize(video,url,true)

4.controlbar.initialize()

Layer update setting (update advanced function)

Player.on (setting parameters in audio and video playing)

Eventpoller = setInterval (function () { get Current event information })

8. Calculating a current bit rate

Document, addEventLister ('set snoop event', function () { dash () ])

In the high-level function of the player of the on-demand unit, an adaptive code rate algorithm and a buffer cache strategy are set. The adaptive code rate algorithm has multiple options and can also be customized, a default algorithm is used in the application, and the audio and video self-adaptation is closed; the buffer cache strategy is provided with cache parameters of initial buffer level, buffer Pruning Interval and buffer ToKeep, and in order to enable the cache speed and the cache size to be within a reasonable interval, the three cache parameters are temporarily set to be 12, 10 and 20 in sequence.

The page design part mainly associates the resource loading keys with the script and designs the positions of the components, and the pseudo code part is not listed because the process is complicated and does not relate to functional design. The player identifies the author unit and the quotation information and realizes the following functions:

(1) Supporting the automatic loading of streaming media by inputting URL addresses;

(2) Adjusting audio and video quality, sound and subtitle display through the control bar;

(3) The progress bar dragging and thumbnail displaying functions are supported;

(4) When a plurality of different streaming media resources exist, the playlist is supported to be loaded;

(5) Supporting the display of the current streaming media transmission related parameters;

after testing, the player can successfully play the DASH streaming media after loading the public network DASH resources, and realize the related functions. So far, the present application completes the production of the DASH player, that is, the realization of DASH on the client.

The buffer cache strategy comprises an LSTM neural network model; the buffer cache strategy is used for adaptively adjusting cache parameters initialBufferLevel, bufferprings interval and bufferToKeep through the LSTM neural network model.

The LSTM neural network model is an important component of the dynamic cache system and is responsible for predicting the network condition in the next time period, and the output result is the calculation basis of the cache parameters, so that the performance of the LSTM neural network model directly determines the overall performance of the dynamic cache system.

The dynamic cache system based on the LSTM neural network model is designed as follows:

redefining a cache strategy: due to the high audio and video transmission code rate, all network resources are prevented from being used for audio and video playing. The bandwidth occupied by audio and video playing is assumed to be 70Mbps. Taking a video with a playing code rate of 35Mbps as an example, the buffering strategy is analyzed by taking 60s as a time period in the application:

(1) When the network condition is good, the audio and video resources are played at the bandwidth of 70Mbps, and besides instant playing, the audio and video in the next time period can be buffered by the same network bandwidth resources, and at the moment, the jamming cannot occur;

(2) If the available bandwidth of the network is below 70Mbps and above 35Mbps, the buffering time can be reduced, the requirement of instant playing can be met, and the playing card pause can not occur;

(3) If the bandwidth resource is less than 35Mbps, the play speed is greater than the buffer speed, and the pause occurs after the buffer resource is exhausted.

Due to the randomness of the network, the predicted data output by the LSTM neural network model actually reflects the variation trend of the packet loss rate, so that the network throughput rate is calculated according to the predicted packet loss rate in the form of average prediction and weighting. In summary, in the present application, the default buffering duration is set to 60s and 30s, x1 represents the packet loss rate in this time period, and c1 represents the actual bandwidth of the current network; x2 represents the average packet loss rate in three time periods, c2 represents the network predicted bandwidth in the next time period, and the buffering parameter setting is shown in table 6.

TABLE 6 cache parameter setting Table

It should be noted that good network conditions do not mean x1= x2=0, but c1, c2 rates are not lower than 35Mbps, and bad network conditions do not mean x1, x2! =0, but the c1, c2 rates are not greater than 35Mbps. According to the method and the device, the influence of the RTT time on the throughput rate calculation result is limited in the calculation process, and the RTT time in the current time period is used for calculating and predicting the throughput rate from the viewpoint of simplifying the processing process.

After the dynamic cache strategy is designed, the dynamic cache system is applied to the player that needs to modify the script, the player cache setting function is in updateSetting, and the cache parameter change path is as shown in fig. 3.

The caching parameters are packaged into an updating object in an HTML webpage, the object is initialized firstly when being called by dash. Therefore, to realize the dynamic setting of the cache parameters, the following contents are completed on the basis of the existing work: 1. calculating actual bandwidth and predicted bandwidth by HTML at intervals, and obtaining cache parameters according to a cache strategy; 2. setting the script as bidirectional binding, and adjusting the cache parameters in real time by the background. In the HTML script, the dynamic refresh calculation of the cache parameter is completed by using a timer, and the pseudo code (algorithm for refreshing the cache parameter) is as follows:

1. reading pred.csv files

2.setInterval(handeldata(){

3. Obtaining the current packet loss rate and the RTT time

4. Calculating the current network bandwidth according to the current packet loss rate and the RTT time

5. Calculating the next time period to predict the network bandwidth according to the predicted packet loss rate and the RTT time

6. Obtaining cache parameters according to cache policy

7. Encapsulating cache parameters as obj

8. Refer obj to the parameter updateSetting ()

9.}, refresh once per minute)

The code successfully executes the data refreshing within the set time after the HTML webpage is opened through testing. After the work of the script part of the webpage file is completed, the second step is to enable the background script to have a bidirectional binding function. The bidirectional binding means that the changes between the webpage and the background script are mutually visible, and corresponding operations can be executed according to the changes of data to update the state of the user. The most common method for realizing bidirectional binding is a subscription-publishing mode, which needs a publisher and a subscriber, in the application, the publisher is a cache policy calculation value, the subscriber is a data.js script data updating module, and the subscriber needs to hijack the data of the publisher. The pseudo code for the changes made to the web page and script portion (i.e., the algorithm for the subscription-publication model) in this application is as follows:

1.Varobj. List = { define subscription event function }

Obj. list = function (event name):

3. defining a subscription event function

Obj. Trigger = function (event name):

5. defining a publish event function

List ("timer refresh" function ()):

7. subscribing to an event: the timer refreshes the data

8. Observing data changes to trigger subscription events

9. The script changes the cache parameters

After testing, the script successfully refreshes the cache parameters in the background, which means that the cache strategy is written into the cache system. So far, the dynamic cache system based on the LSTM neural network model is successfully designed.

The original video file storage module, the distribution management control module, the transfer module, the core routing unit and the on-demand unit are networked through a future network; the future network comprises an IPV9 network. The distribution management control module is networked with the transfer modules of each province by adopting a future network IPV9, a national backbone network is built through backbone routers, and the IPv9 decimal network has the advantages of safety, controllability, compatibility, large number of addresses, low communication cost and the like. The method has great advantages in networking, safety and the like, and can meet national high-speed services. Otherwise, the market price of a trans-provincial gigabit data special line can reach dozens to one million, and if networking in the national range is to be realized, the cost is too high.

The user router is deployed on each home metropolitan area network broadcasting module, future network networking is also realized between the transfer module and the home metropolitan area network broadcasting module, a large number of IP addresses can be provided through the future network networking, and the adding requirements of a plurality of home metropolitan area network broadcasting modules are met.

In the home metropolitan area network broadcasting module, future network networking is realized between the core routing unit and the broadcasting unit, and network transmission is faster, better effect and safer through the future network networking.

In the embodiment of the application, a transmission mode of combining an IPV9 backbone network and an operator metropolitan area network is adopted. The metropolitan area network is a link necessary for connecting a user access network and a wide area network, and has main functions of data aggregation and classification, local exchange, export traffic forwarding, service control and the like.

The access to the metropolitan area Network is performed using Optical Transport Network (OTN) technology. The OTN is a transport network covering an optical layer and an electrical layer based on a Wavelength Division Multiplexing (WDM) technology, and is also a next-generation backbone transport network, which inherits dual advantages of a Synchronous Digital Hierarchy (SDH) and a WDM, adds an intelligent optical switching function, and can implement optical cross by data configuration without manually jumping an optical fiber, thereby greatly improving maintainability of Wavelength Division equipment and flexibility of networking. The OTN is not a network structure, but a transmission technology applied to network construction, and may be applied to metropolitan area network construction.

The metropolitan area network is also provided with a CDN network. The CDN can redirect the user request to the service node nearest to the user in real time according to network flow, connection of each node, load conditions, distance to the user, response time and other comprehensive information, so that the user can obtain required content nearby, the problem of resource congestion of the Internet is effectively solved, and the response speed of the user for accessing a website is improved.

The application has the advantages that:

(1) The IPV9 network has good compatibility and can effectively transmit data.

(2) The transmission speed of the networking mode of the IPV9 backbone network and the operator metropolitan area network is extremely high, and the bottleneck problem of network transmission is effectively solved; the network bandwidth in the mode completely meets the requirement of transmitting high-bit-rate audio and video files.

(3) The DASH technology can effectively process original audio and video files provided by a service provider; an on-demand system with Dynamic Adaptive Streaming over HTTP (DASH) technology based on HTTP as a core is designed. The method comprises the steps that original video files are subjected to diversified processing at a server side (namely a distribution management control module of the application), a player capable of transmitting videos in a segmented mode is designed at a client side, a streaming media server is built, and the problem of cross-domain is solved.

(4) The client can successfully acquire the audio and video resources stored by the streaming media server.

(5) Js open source project design based on DASH can successfully play audio and video processed by the DASH technology, and can realize various preset functions.

(6) The whole playing effect of the on-demand system is good, and the resolution ratio switching is very smooth.

(7) Aiming at the defects of a cache mechanism in the process of transmitting high-code-rate audio/video files, the application provides a dynamic cache system based on an LSTM neural network model. A caching strategy is formulated based on a prediction result output by the constructed LSTM neural network model, and finally background data of the player is successfully modified, so that the caching strategy is reasonable.

(8) The on-demand system designed by the application is a complete, high-speed and high-quality home theater broadband metropolitan area network on-demand system.

The real 4K home theater broadband metropolitan area network on-demand system based on the future network constructs a national backbone network based on a future network IPV9 from a distribution management control module to a transfer module positioned in each province and city of the whole country, performs networking based on the future network from the transfer module to a home metropolitan area network on-demand module in the province, and performs networking based on the future network between a core routing unit and an on-demand unit in the home metropolitan area network on-demand module. By networking based on a future network, the requirements of stability, safety and rapidity of transmission of larger original audio and video files can be met, the communication cost of the system is greatly reduced, massive IP addresses are provided, and the bandwidth and server resources of nodes in the network are fully utilized; the transmission rate can reach 50M-100M, and the bandwidth can reach 100M-1000M; network transmission is safer.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A real 4K home theater broadband metropolitan area network on-demand system based on a future network is characterized by comprising:

the transfer module is used for receiving the DASH file transmitted by the distribution management control module, transmitting the DASH file to a home metropolitan area network broadcasting module, receiving feedback information transmitted by the home metropolitan area network broadcasting module, and transmitting the feedback information to the distribution management control module;

the household metropolitan area network broadcasting module comprises:

2. The broadband metropolitan area network multicasting system of claim 1 wherein said distribution management control module comprises: an encoding unit and a dividing unit;

3. The broadband metropolitan area network multicasting system of claim 1, wherein the distribution management control module is configured to obtain the DASH file in the form of an executable file based on an open source DASH, custom file configuration.

4. A broadband metropolitan area network multicast system according to claim 1, wherein said transfer module is used to build a streaming media server, and cross-domain control is performed between said distribution management control module and said home metropolitan area network multicast module through said streaming media server.

5. A broadband metropolitan area network multicasting system according to claim 1 wherein said on-demand unit comprises: the system comprises a streaming media control subunit, an HTTP access subunit, an analysis subunit and a video playing subunit;

the parsing subunit is configured to parse the DASH file to obtain parsing information;

6. A broadband metropolitan area network multicast system according to claim 1 wherein said on-demand unit comprises: a code logic compiling subunit and a webpage compiling subunit;

and the webpage compiling subunit is used for compiling an HTML5 webpage file.

7. A broadband metropolitan area network multicasting system according to claim 1 wherein said on-demand unit is provided with an adaptive code rate algorithm and a buffer caching strategy.

8. The broadband metropolitan area network multicast system according to claim 7, wherein said buffer caching strategy is configured with caching parameters initialBufferLevel, bufferpringing interval, and bufferToKeep.

9. A broadband metropolitan area network multicasting system according to claim 8 wherein said buffer caching strategy includes an LSTM neural network model; the buffer cache strategy is used for adaptively adjusting cache parameters initialBufferLevel, bufferpuning Interval and buffertoKeep through the LSTM neural network model.

10. A broadband metropolitan area network networking system according to claim 1, wherein said future network comprises an IPV9 network.