Published Online: May 07, 2018
Page range: 23 - 26
DOI: https://doi.org/10.21307/ijanmc-2018-005
Keywords
© Wang Pengfei 2018 et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
There are many products in the market for hotel monitoring, but these products are often expensive and cannot be widely applied to all kinds of hotels. Based on the above, this system using Linux operation system based on the ARM9 processor to construct the monitoring system, which can be widely used in the hotel lobby, stairs and building dead ends, so as to ensure the real-time monitoring of the hotel in all directions [1].
This system is based on the Linux embedded system, mainly composed of the software and the hardware [2]. It includes the image and video collection, the display module, the data processing and the transmission module. The network transmission environment is LAN. The structure of the system is shown in Figure 1.
Figure 1.
Overall structure diagram of the system
The image acquisition module collects the image data through the USB camera [3]. The data processing module mainly deals with the user commands and the operation of the generated data. Data transmission module is currently popular browser /Web server mode, through the embedded Web server communicates the client PC browser between the HTTP data format. The image display module is the PC port under the LAN, which sends data requests to the Web server through the browser web pages [4].
According to the functional requirements of this system, the following hardware devices are needed. The specific hardware structure is showed in Figure 2.
Figure 2.
The system hardware structure
In Figure 2, ARM9 S3C2440 is the main chip of the system. The image data was collected by the USB camera; the collected images stored in SDRAM for transferred facilitate [5]. The video data stored in Flash. By the DM9000 card, the network module could communicate with the development board. At the same time, in order to realize the serial communication interface RS232 combined the monitoring system and PC. The wireless network connects the wireless LAN and the development board for the wireless communication.
Based on the Linux operation system, the image acquisition program, the Web server BOA and the CGI/HTML5 were combined together [6]. The software structure is shown in Figure 3.
Figure 3.
The system software structure
The operating system uses the management processors, the memory, the devices and the user interfaces. The Linux operation system could be reduced for the requirement function [7]. The application program could visit the device by the related API and then controls the hardware through the driver.
V4L (Video4 Linux) is the driven structure of the video device in the Linux kernel. It provides a unified function interface for the upper-layer applications accessing to the underlying video devices.
V4L2 could support the multiple hardware devices and the running framework of V4L2 in Linux is shown in Figure 4.
Figure 4.
The structure of V4L2
From Figure 4, the frame structure mainly includes four parts. It is showed in Table 1.
TABLE 1.
THE FRAME STRUCTURE OF V4L2
After the embedded processor gets the image information, the JPEG compress program is executed and the image acquisition is completed. Finally, the video coding is carried out by the MPEG-4 video coding standard. The process of video image acquisition is shown in Figure 5.
Figure 5.
The image collection flow chart
First, the system creates a file to save the collected image information. Next, open the USB camera’s device. With opening the device file, gets the driver information of the device. After the image formatting is completed, the image buffer will be applied [8]. Then establish the mapping of the kernel space image buffer to the user space. Finally, using the camera to capture the image data, the collected data will be saved to the driver’s buffer [9].
After the video image file collection is well done, the Web server should be established. Through the network protocol, the client can browse the Website and download the files. That is the mainstream browser/server mode [10].
With the characteristics of embedded Linux system and the requirement of the development board hardware resources (DM9000), the communication between the Web server and the client using the TCP/IP protocol. By the CGI program, realizes the video data transmission. The transferred diagram among the development board, server and the client is shown in Figure 6:
Figure 6.
The net transmission based on the TCP/IP protocol
DM9000 net chip sets the IP address and the physical address of the development board. When the development board works in the normal Linux system, connects the RJ45 interface to the router through the cable, the wired/wireless devices in the same local area net can achieve the network communication.
The system could browse and download the video files on the web page which collected by the development board [11]. So the server needs to respond to the request from the client web page and access the files in the server through the CGI common gateway interface program. The CGI program’s model in the server is shown in the Figure 7.
Figure 7.
The flow chart of the CGI
The CGI program is running on the server and the client sends a CGI request through the HTML pages to the server. The server receives will be executed after the specified CGI application, then the CGI application sends the result to the client web browser. This result is formatted into HTML format and displayed by the browser.
In this paper, using our school hotel as an example to implement and test the function of the above system. The system ensures the overall stability and smooth operation of the system, and completes the image video acquisition and the client’s web page display [12]. The monitoring result is showed in Figure 8.
Figure 8.
The test result of the proposed monitoring system
The all-around monitoring of the hotel has become a basic condition for safety. Video surveillance is not only small, stable and safety, but also does not appear the “dead angle” phenomenon than the artificial monitoring. Based on the characteristic, the proposed video acquisition and transmission system has a very good market prospect.