Design And Implementation Of Embedded Video Conferencing Software

With the rapid development of the internet and multimedia technology, multimedia communication is playing a major role in Internet applications. Network video conferencing is one of the most common applications of video conferencing. The architecture of video conferencing system can be central or distributed. The traditional centralized architecture suffers from high control and deployment cost due to high performance requirement for central server. The distributed architecture does not need a central server, this low resource consumption and easy to use style is preferred in recent video conferencing applications.With a thorough discussion of commonly used techniques in video conferencing, this thesis discusses an implementation of such a video conferencing software based on a high-performance audio/video codec hardware and embedded Linux software platform. Compared to the systems that implements on PC, such an embedded implementation has the advantage of small capacity, low power consumption and high stability. The system provides friendly user interface, with which users can make audio and video communication conveniently, with support for common conference controls, such as privilege management and conference management functions such as enter a conference, talk request and leave a conference. As traditional centralized video conferencing system suffers from high server load and low scalability, our system is based on a distributed architecture with no central control server in place. We implement the video conferencing software based on SIP protocol with proper extensions to meet the control requirement. The terminals are capable of signaling and media streaming control without additional central server, such a system is easy to deploy and use. Our test result shows that a video conferencing system composed of such terminal can realize the video conferencing function with a high stability and good real-time characteristics.