Design And Implementation Of AVS Based Instant Messenger System

Network elements unconsciously infiltrate to society's every corner along with the rapid developing network technologies. During this process, the network communication becomes to be a most novel, fashionable, convenient and multiplex way in modern society human communication. Instant messenger also becomes the netizen's most commonly used network tool. At the same time, the audio and video communication technology has a good application in instant messenger along with network and multimedia technology's development. It has infused a new vigor for the instant messenger's further development. However, the present domestic situation is that most of the core technologies rely on purchasing overseas correlation technique provider's solution. Especially some technologies such as audio and video coding and decoding involve to extremely expensive patent charge question. It restricts and affects our country instant messenger market even the entire audio and video industry's healthy development seriously.AVS standard is the fully Intellectual Property of second generation Source Coding-Decoding Standard owned by China. It is the series of "information technology advanced Audio and Video Coding" standard abbreviation and established by the AVS Workgroup which was authorized and established by Science and Technology Department under National Information Industry Ministry in June, 2002. AVS standard has got great development and has been applied in many fields now. However, the application of AVS in the so broad instant messenger market is nearly zero. So developing instant messenger based on AVS and extending its usage in commercial product is very important. It has very big significance for filling the blank of AVS standard's usage in this technology filed and promoting our audio and video industry developing. This system's research and development are precisely based on this purpose.This paper analyses SIP, AVS standard, AVS video coding-decoding technology and media stream's transportation and synchronization after investigates the instant messenger market's present situation and the correlated realization techniques widespread. Especially has study on AVS standard and AVS video coding-decoding standard, and compared with other main standards. Design and realize function completed instant messenger. During the process of designing and realizing audio and video communication, we make certain adjustments to the AVS video technique related algorithm to adapt in the real-time application of instant messenger. Transportation and synchronization are very difficult problem during audio and video communication. We bring forward transportation and control solution based on RTP/RTCP, and get a good effect. In this paper, we use the video coding-decoding technology of AVS standard. Also it is firstly used in instant messenger. Our instant messenger system is designed based on SIMPLE, so it has nice expansibility and intercommunion. It can communicate with the other IM which follows the same standard. This specialty not only can bring nice convince, but also can avoid the complicated conversion and procession because of different IM protocol. It can make fully use of current resource.