Design of real-time VOD system based on web

VOD (Videoondemand) is called video-on-demand, also known as interactive TV on-demand system. The traditional TV system information is transmitted in one way and the user can only receive it passively. And VOD is a "user autonomy" of the new concept based on the two-way video and audio information system, to achieve the needs of users to play video audio programs ideal. VOD is an important part of the future information superhighway architecture, and it is the soul of broadband service in the future Information service. The technology is a combination of multidisciplinary and multidisciplinary integration of computer technology, network communication technology, multimedia technology, TV technology and digital compression technology.

The VOD service, which was developed in the late 90, has been widely used in all major star hotels and upscale residential districts, and has become an essential facility for improving service standards and increasing competitiveness. Through the VOD system, people will be able to watch the most popular film and television programs, query a large number of service information, online shopping, understand the latest financial developments, enjoy high-quality multimedia video programs ... Enjoy a full range of multi-functional information services.

At present, text, images and narrowband audio and video signals have been digitized, and can be stored, transmitted and reproduced through the network; However, these traditional means can not fully meet the needs of today's society for high quality, continuous multimedia such as high fidelity audio and television quality video, including the requirements for mass data storage and continuous playback. They require a large-capacity storage device, requiring a broadband network environment and, most importantly, the need to ensure real-time transmission. Traditional technology can not meet the strict real-time and large capacity requirements, its technical bottleneck is particularly reflected in network bandwidth, file system and storage device I/O performance of the three aspects.

The real-time High-definition video-on-demand system is launched in this context, which includes client, server-side software, and set-top box hardware. The system is designed for the demand of the Chinese users and small and medium sized networks for the broadband Information Service, the system is based on the Browser/applicationserver/databaseserver model, and the Internet technology is used as the basis of the information service. Through the design and realization of real-time data stream protocol to form the control layer of multimedia data transmission, by supporting distributed video service and distributed video file system to ensure the adaptability of the system to different network scale and specific users, it provides a kind of advanced technology for continuous multimedia data storage and real-time transmission. An economically effective complete solution.

The working principle of real-time VOD system

The system utilizes the advanced and increasingly mature browser/applicationserver/databaseserver three layer application development technology and the Internet technology realization, may use the ordinary PC machine (or the Set-top box) as the Operation Terminal, User Terminal software configuration is very simple: operating system (windows95/98 Chinese version) +web browser (netscapenavigator) + video player (client standard plug-in).

The development model of three-tier application has become the most popular development mode because of its advanced development technology, superior manageability, maintainability and simple and convenient application mode, which replaces the traditional Client/server two-tier application development mode. It minimizes the client's hardware and software requirements, reduces maintenance, and eases program modification and upgrades by minimizing the application's clients to a single browser through a centralized processing model.

At home and abroad at present, the development of Internet applications and three-tier applications has been very common, in the technology has been very mature and advanced, including related technologies including security mechanisms, IC card applications and online payment technology has been more mature. In the next few years, this model will become the mainstream application model of computer service information System.

The basic working methods of the system are:

1, through the browser login user account, select the type of service;

2, search, access to a variety of traditional multimedia resources and browse video program management pages. The browser obtains the information through the Internet service (Web server, FTP server, etc.) and displays the result in the Customer window;

3. When the user chooses the video service, the browser invokes the video program management script installed on the Web server;

4, Program management script calls the IIS database connection object, will store in the program database the video program list to present to the user;

5, the user chooses to play the video program, the broadcast script on the Web server will be called;

6, the script through the program server to select one or more video server, and return the results to the browser;

7, the browser activates the video player;

8. The video player requests the video server to transmit the data, and in decoding, playing the movie while adjusting the transmission rate and responding to the user VCR control, these control operations by the player and the video server through consultation to complete;

9. During the program playback or during the program playback, users can jump to other pages by interacting with the browser interface and the player interface.