Research And Design Of IP-based Multifunctional Video Conference System

With the development of computer and Internet, a multimedia intercommunion method combined with characters, voice and visible images are much more preferred than traditional character intercommunion. The rapid development of transformation and communication technology for digital images promotes the realization of the multimedia intercommunion. A video conference system can be recognized as an internet based multimedia intercommunion for a conference attended by people in several different places. This system can provide an excellent real time communicating platform for the attendee, who can make the video, voice and characters intercommunion based on the Internet. At present, the technology development and application of multimedia intercommunion have been being in an increasing scale. Multimedia intercommunion system as a rising communicating tool has been widely used in every walk of life in order to promote the work efficiency and competition.The multimedia intercommunion criterion H.323 made by ITU-T is firstly introduced, especially for the system structure and standard protocol stack of H.323. The connection process of a multimedia video conference is also analyzed. The feasibility of QoS used in a multimedia video conference system is then explored, including the application of QoS in IP internet and in H.323. The compression coding of Low Code Rate in the multimedia video conference system is also studied.The program design of a video conference system has been conducted based on the API -A Real Time Communication provided by Microsoft Corporation. And the specific realization process is also illustrated. The results show that this system can be applied in the normal computer terminal with less hardware for a video conference on the Internet. The meeting fee can be greatly reduced because the words, video and voice communication are all based on the Internet. Based on the video intercommunion, the digital conference function has been strengthened and number of the electronic white board has been increased in this system, which makes the communication for the attendee more convenient.A video interception module has been developed based on the above-mentioned video conference system. This module is created by using the tool pack of VFW, which is video program software under the platform of Windows. Based on the interface function provided by VFW, the video and one frame image can be intercepted, and the intercepted images can be carried out in format transformation, then the transformed images can be displayed to attendee in this module.The digital conference function has been enhanced, the number of the electronic white board has been increased and the digital image transformation function has been strengthened in the developed video conference system presented in this thesis. These progresses can be directly used in the long-distance monitor, business conference and long-distance training, and can provide a strong foundation for deep development as well.