The Design And Implementation Of Embedded Group Video Chat Module

In recent years, with the rapid development of the network technology and multimedia technology, many kinds of applications of multimedia appear and have good development. In this context, efficient and easy-to-use multimedia terminal devices become more and more popular in many kinds of institutes and companies, and it brings convenience and funny to life.Group video chat system becomes more and more popular and focused by researchers, for its features of real-time and affability. With a thorough discussion of key technologies which comprise SIP protocol, streaming media transmission based on RTP protocol, media codec and UI implementation based on embedded Qt, this thesis discusses the design and implementation of a group video chat software which supports small-scale group chat.In this thesis, we firstly make a research on two available architectures to build the system. One is centralized architecture, and the other is distributed architecture. Take the features of small-scale and the limitation of the hardware resource into consideration, and after a comparison of the two kinds of architecture, we choose the distributed architecture. On the side of the choice of the signaling protocol, the smart and easy-extended SIP protocol meets the need of the group video chat system. The system realized much extension based on SIP, like adding new partners and kicking out partners and so on. On the side of media transmission, with the hardware platform with suit of SDK which provides the packing and unpacking of the RTP data packets, we can conveniently realize the transmission of the streaming media based on jrtplib function library. On the side of the codec of the media data, the hardware platform provides the high-performance audio/video codec hardware, with which we can conveniently realize the A/V codec. On the side of the user interface, we choose the embedded Qt as its technology to implement a perfect and friendly UI to provide user with convenience and enjoys. The embedded group video chat system which based on distributed architecture, withSIP protocol as its core technology, realize many controls on group chat and the codec of media data and the transmission of streaming media. The system has feature of real-time and dependability to meet the need of group video chat of small scale.