Design And Implementation Of The Video Capture And Transportation System Based On Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSN) have been paid much attention recently in the realms of the image, video capturing and other information-intensive sensing which is developed on the basis of the traditional wireless sensor networks. As a novel information acquiring and processing technology, WMSN can be used in the military, civil and commercial fields with promising prospects. Not only does it have the advantages of self-organization, unmanned monitoring in the traditional wireless sensor networks, but also it is capable of faster transmission, better processing capability, handling more complex tasks and richer medium awareness. For these characteristics, specific software used in multimedia sensor node is badly needed in order to complete the more complex tasks like collecting, processing and transmitting.In this thesis, the multimedia sensor networks are firstly researched. Then a set of video transmission system named VTSN is designed and implemented, which is applied in multimedia sensor networks. The System is based on embedded Linux environment which has the good portability and scalability. Meanwhile the advanced multi-media development framework is adopted known as Gstreamer. After a series of video stream processing and image optimization, the system can encode the video stream and transmit it based on the RTP protocol via V4L2 interface. On the other hand, the remote terminal will take the corresponding inverse process to receive and decode and re-display the video. What's more, the system requirements can be met through the process management functions which could reach the goal of intelligent running.Towards the problem of unstable video streaming caused by the high dynamic networks existed in WMSN, the performance of VTSN is enhanced in terms of the parameter optimization and system fabric improvement. The thesis adjusts parameters from the collection part, processing part and transmission part to obtain the most suitable ones for WMSN. Meanwhile, a dedicated queue module is also added, which provides a buffer zone specially designed for mandatory multi-threaded systems, in order to guarantee the reliability and stability of video transmission.Finally, the method of transplanting the system VTSN to the hardware platform of sensor node is described to make sure the system designed can run on the target platform to complete the functions of the video information gathering and transmitting.