Research On Real-time Video Transport Technology Based On Linux

The topic is from the item "portable video cipher machine" of General Staff Confidential Bureau. The general considerations of item is to apply wireless net as communication means of video transmission under specific environment to establish video security communication system with strong mobility, portable and classified capacity, so as to meet the ever-growing mobile video requirements of different departments (campaign, intelligence and scout) in our army. As one of the subtopics, real-time video transmission is to optimize the quality of video transmission on wireless communication net. However, compared with wired net, although the wireless communication net has the essential condition of real-time transmission video information, its interference is serious and the possibility to produce error code and video communication dynamic fluctuation is greatly enhanced. Because the net can not supply the service quality assurance of video business, a lot of work should be done to guarantee the transmission quality of real-time video data such as how to improve the robustness of video compressed encoding and according to the real-time control of wireless channel state and the transmission of video data, how to improve the anti err code and anti time delay capacity. Otherwise, computer operating system is developed to flush-bonding operating system and emphasized the volume, power consumption and portable ability, so combining video communication with flush-bonding system to compose the video transmission system user terminal has greatly superiority.In this paper, we focus on the transport controlling technique for real-time streaming video. A preventing congestion strategy of adaptive adjustment method for client side buffer based on UDP is proposed in this work. And combining the characteristic of video streaming, we work a controlling arithmetic for streaming video transport based on the estimated status of network. Aim at the improved scalable encoding scheme based on position reordering and VLC reshuffling, we propose an adaptive unequal packet loss protection strategy to offer QoS for the scalable streaming video in network. It can determine current network status and estimate available bandwidth resources by calculating arithmetic equation, then adjust the number of sending layers and forward error correction schemes of those which are different important. In accordance with many simulation testing, this controlling strategy can relax the load in the network effectively and improve the whole system quality for the video communication. In order to make the embedded system process the real-time data flow, we extend the real-time data interface to it, including the hardware extension and the driver program.