Video conference system is a kind of multi-media communication technology. People can use it to meet with others on network. End-point is the important segment in video conference system, and video codec is the core. In this paper, a thorough study is carried out over the key algorithms of distortion constrained video codec, several optimization methods are proposed to enhance the coding speed and promote the applications of video coding in actual practice.Because of all of above, Xi'an government has certi...