Design And Implementation Of Video Conferencing

In this thesis, an experimental video conferencing system is designed and some relating key technologies are studied, which include:(1) MMX?technologyOn the basis of the theory of video compression and ITU-T H. 263 recommendation, the MMXIM technology is used in two largest parts of the recommendation: motion estimation and DCT (iDCT), a desired result has been got.(2) Multi-cast technologyIn this thesis, multi-cast technology is studied and implemented by using Windows Socket2.(3) DirectDraw technologyAs a COM of DirectX, DirectDraw is studied and is used in video display. This makes the video display more fast because it can access to the hardware directly.(4) RTF protocolBecause of the real-time requirement, RTF is studied and used to transmit audio and video data on network on UDP protocol. In this way, the problem of delay and jitter is resolved successfully.The ITU-T H. 323 recommendation is studied in this thesis also, because it is a good reference to design a video conferencing.By using these technologies, a video conferencing system is implemented based on LAN. It is a good experiment of the application of multi-media communication.