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Position:IcFull.com » IC Electronic information » Category: L

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Linux platform applications online advertising machine design

In Electronic Infomation Category: L | on April 15,2011

Online advertising machine known as digital signage system, is in the network era of rapid development of information arising in the context of a new network of multimedia information distribution system. Based on this system, the user can display a variety of ways in the public release of public information on the contents of the terminal. Currently, digital, network, information-based multimedia network advertising to become a major highlight of the media market, but the stand-alone version of the advertising and MMBT2907A datasheet and media release form of the single has been difficult to meet the increasing market demand, domestic and MMBT2907A price and foreign are actively involved in multi species and MMBT2907A suppliers and multi-media, interactive form of online advertising Machine. In this paper, the advantages of Linux to embedded system design, the majority of Linux systems using open source software and support tools to construct low cost, features a sound and flexible network media distribution network advertising systems.

1 System Overview

Shown in Figure 1, the entire system can be divided into advertising monitoring terminal, the server control center, advertising display terminal three parts. Monitoring control terminal through the Web browser, enter the administrator receives the page control commands, routed through the network control center to submit the form to the server. Monitor Terminal Server Control Center, submitted under different categories form the corresponding CGI call the appropriate routine to start the process of Socket Services, the establishment and development of board Socket * network communication between the service process, passing the corresponding control commands and information. Advertising display terminal control commands and parse the appropriate information, to control the display terminal device information broadcast media forms.


Figure 1 System Diagram

1.1 hardware environment

Advertising monitoring terminal and server control center equipment for the ordinary PC. Advertising display terminal is used in embedded VT8430 core development board wins. The development board is the core processor technology introduced Sheng multi-standard digital audio and video media processing chip CSM1200. The chip ARM9 core, supports MPEG2, H.264, AVS HD and SD decoding / output, video output support PAL/NTSC/480p/576p/720p/1080i. At the same time, CSM1200 is a rich media capabilities and powerful peripherals embedded platform SoC, the flexibility to choose a variety of LCD or other display device, information distribution node as advertising media playback device.

1.2 Software Environment

Monitoring control center terminal and the server using Linux system platform. Monitoring terminal only able to provide a normal Web page browsing can be achieved through the browser interaction information. Server control center and display of multimedia information distribution terminal is a key part of the environment need to configure the following relevant:

Construction of CGI module. CGI-based Web browser used to design the B / S (Browser / Server) system architecture, the client can not (client) in the case, widespread use of Web browsers buttons, input boxes, fonts and colors and other interfaces element. Browsers on different platforms by monitoring terminal can control the form to submit information interaction. Download the official website after libcgi 1.0.tar.gz source package, unpack, compile and install.

create and configure httpd service. Official website to download httpd 2.2.4.tar.gz, unpack, configure, compile and install, set the corresponding CGI program and the html path and directory services to provide monitoring client Web browser control page directory and a different set of CGI routines storage directory.

configuration database. Sqlite3 database installed to provide a variety of media information for the query, insert and delete and other control operations. SQLite is stored in a single disk file data in a complete system, especially suitable for embedded system design. In Ubuntu10.04 server platform, use aptitude install libsqlite3 0, libsqlite3 dev, libsqlite3 libsqlite3 doc and open source software package can be.

custom display terminals Linux system. Display system CSM1200 ARM9-based chip, the use of arm 9tdmi linux gun cross compiler tools, the kernel source package based Linux2.6.27 custom development board for the display platform, Linux operating system environment, see reference [1]. Uboot kernel compiled after the programming, the production of root file system, and set the startup mode to load the Linux production kernel. Detailed steps, see reference [2].

Qt environment to build display terminal. Qt GUI display terminal through the broadcast media information, the first open-source software package for Qt qtopia core opensource src 4.2.2.tar.gz, unpacked setting arm 9tdmi linux gun for the compiler environment , compile and install Qt package, copy the necessary resources to the development board file system.

Most of the built environment can be obtained from the official website of the corresponding open source packages installation and detailed configuration information.

2 system features modular design

System Functional Block Diagram Figure 2. Monitoring terminal control page from the Qt, Mplayer control page and the file update control pages. Monitoring control page in a different trigger a control operation, to access the server through the Web functionality to the server control center to submit a different form. Control center of the main part of the site by the server Web httpd, CGI control module, the database Sqlite3 and TCP Socket Client-side components. According to the different monitoring terminal to submit the form, the corresponding control program will execute CGI, CGI program in the corresponding entry, delete and update Sqlite3 database operations, while calling and open the corresponding Socket Client process control commands and the corresponding database Information submitted through the network to the display terminal Socket TCP Socket Server * server. Display terminal TCP Socket Server * TCP Client-side receiving control from the command, control commands through the analytical categories, will air control commands and related information is written to the local or Qt Mplayer local socket server and stored on the local Linux file system. Qt Mplayer player player and read their local socket file system control information, call the appropriate audio and video drivers to control the audio and video files in the Qt Mplayer-side interface and the display and playback.


Figure 2 System Functional Block Diagram

3 key algorithm

3.1 database design

Control terminals according to advertising monitoring the different media types, the use of Sqlite3 database maintenance media video player, photo background and Qt subtitle information. Database theory see reference [3]. For advertising monitoring as administrators and managers, managers need to design ID, login password and user name information corresponding to the advertising machine monitoring and management. Video and pictures on the media is concerned, involves the insertion of the corresponding media object, delete, update and control operations such as the play order, so were set ID, file name, adding time and make the appropriate order number to the maintenance and control of management. Corresponding database design schematics shown in Figure 3.


Figure 3 database design schematics

3.2 advertising display terminal

Advertising display terminal principle Qt GUI shown in Figure 4. Qt interface design principles, see references. Development board is powered, the main program begins execution, Mplayer media player reads the stored video files during the development board to loop playback, while * their local socket. When the network communication module will control the terminal control commands coming from Mplayer player written after the local socket, Mplayer will perform the appropriate response to control commands, such as pause, play next, re-start playback. Qt GUI application started, first read the local image files and text files, for loop. At the same time, Qt GUI program * command * Qt GUI thread local socket. When a control command, Qt GUI application to perform the appropriate actions, such as closed, open, update rolling subtitles.


Figure 4 Qt graphical interface schematics

Local socket with the local TCP Socket Server-side communication, and control commands related to the final upload, the local TCP Socket Server command from the control center is a TCP Socket Client-side on the control command upload. Part of the local control socket Socket Server code is as follows:

While (1 ){//*, resolution, receiving a command from the server-side connection

Write_domain_socket_qt (); / / Qt socket

... ...

Write_domain_socket_player (); / / Player

... ...

}

3.3 Server Control Center

Server administrator control center by passing the users control command, to control the display terminal images, video and print media playback status updates and changes. The user or administrator Qt Mplayer by clicking on the various control buttons to control page and update the media file manipulation, trigger a variety of CGI routine monitoring center, so the various control operations monitoring terminal will control operations and the corresponding CGI routines one by one correspondence. CGI routines TCP Socket network communication through the terminal server to the display control command to submit the appropriate and relevant control information, to complete a variety of media information on the operation of control. Linux Network socket programming, see reference [6].

Figure 2 shows, the display terminal into Qt and Mplayer module. Which, Qt module for playing the media image and caption information, Mplayer is responsible for playing all kinds of video files. Video and image files for the media information in a controlled manner is basically divided into two types: one is not simply content with the upload operation mode of media control operations (such as video playback pause, adjust video sequence, etc.), only need to click the button to complete the relevant control; the other is based on the updated file upload media operations, such as video files, pictures, database updates and other operations. Therefore, the combination of these different control methods are given subtitles rolling advertising machine, pure file upload control and command key algorithm.

Qt update the display terminal forms part of the marquee is as follows:


"" ""

""

Value = chang_list >""

""

Value = updated text > "" ""

Name = up_txt cols = 30 rows = 8 wrap ="">

"" "" ""

Add user control page updated Qt text, click the Update button will trigger the change subtitles subtitles CGI routines. qt_change_list.cgi routine will create a development board from the local to the display of the TCP Socket Server-side TCP socket connection, and control command "Update Text" and the text with the upload to the TCP Socket Server-side server.

Control commands to control advertising forms part of the design are as follows:

For simple control commands, advertising is relatively simple design of the terminal, for each control command corresponds to a different CGI routines and command macro definitions, each routine by the corresponding control command to Socket Upload can be achieved.


"" ""

"" ""

""

Value = control command > ""
Upload file

key form part of the design:


"" ""

""

Size = 25 maxlength = 100 >""

"" ""
Will be based on Qt

file upload pictures and video files to upload different invoke the corresponding routines. Here in addition to pictures or video files uploaded to the development board display outside the terminal, but also to the monitoring center Sqlite3 database server, add the appropriate resource information and status information, according to a database of previous design attributes of different media types to add the appropriate domain relevant information in order to follow the insert, sort, delete and update operations. Where transmission model using multi-threaded design Uploader my_scp achieve greater speed video and image files transfer, on the multi-threaded programming, see reference [7]. Upload file part of the code is as follows:

Sqlite3_mprintf (); / / add the relevant information to the database

Sqlite3_exec (); / / add the upload to the database records

3.4 Monitoring Terminal

Order to improve safety performance, you need to set the user password feature. Administrator user name and password match the input, you can get control of advertising rights. According to the different types of advertising media, respectively, Qt is designed to control page, Mplayer control page and document control page updates. Different control by controlling the page, you can control the different advertising media player operations.

4 Conclusion

The project design and the use of Linux open source software tools to build networks based on embedded multi-node system, the superior performance of advertising and, ultimately, a satisfying result. The design of the system not only covers the development of Linux system software and hardware technology, but also covers a variety of embedded product design and overall quality of a number of skills, has some practical value.

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