Research On Technologies Of Audio And Video Processing And Transmission Of Wireless Video Intercom System

Wireless video intercom system can achieve real-time transmission of voice and image, and satisfy the needs of construction and maintenance of power facilities, mine construction, mining, oil fields, military exercises and other needs of many special occasions. So that it increasingly becomes an extensive research focus. The rapid progress of wireless communication technology and video compression technology, provides a technical basis to build a wireless security monitoring system for satisfying the actual needs.The thesis made in-depth research of video processing and transmission technology of wireless video intercom system, combining the demand of the power facilities construction and maintenance. It had great practical value.This thesis presented audio and video processing and transmission of wireless video intercom system as the main line.The DM355 processor is proposed as the core in the wireless video intercom system design plan.In this thesis,it presented the hardware environment and software environment design and build processing of audio and video subsystem of the wireless video intercom system, and analysed the algorithm principle of audio processing technical standard ITU-T G.711 and video processing technical standard MPEG4,raised the specific implementation method based on audio and video processing algorithms, and verified the audio and video processing effects. Based on analysis of transport layer protocol TCP and UDP,the thesis proposed the MPEG-4 video streaming transmission plan by the RTCP control WLAN,which combined RTP and UDP.According to the principles and provisions of packaging RTP MPEG-4 video streaming,the thesis presented the specific algorithm of packaging MPEG-4 video streaming.The hardware circuit of wireless video intercom system consists chiefly of central control module with the core DM355, power management module, audio processing module, video input and output modules, video processing module, memory storage modules, data transfering module and signal interface,and so on. Through migrating Linux kernel, downloading and curing Linux kernel and file system, designing Linux driver, we built the software operating environment of wireless video intercom system.On this basis, It achieved and verified the audio and video processing by programming.