Based On The Ip-videophone H.263 + Encoder And Its Optimization,

With the coming of IT era,simple media service can't satisfy the need of person. So much attention has been focused on how to provide better service under present condition. ITU-T has released some standard about multimedia communication in the past several years,such as H.320,H.323 and H.324. These standard ensure that the products of different company can be compatible each other. Especially H.323 standard which apply on IP communication provide a unifiable standard.During the past 20 years,DSP has broader and broader application because it fit digital signal processing much better than MCU. It can execute more complex algorithm and it is cheaper.So we designed a videophone system based on H.323 and DSP.The core of video communication is image encode and decode. There are many video compression standard such as:H.261,H.263,H.263+,H.263++,MPEG1,MPEG2,MPEG4,MJPEG. Which standard to use is decided by the image quality demand of the system and the bandwidth of corresponding channel. In our monitoring system,we decide to use the standard of Video Coding For Low Bit Rate Communication-H.263,because it can get better tradeoff between bit rate and image quality.This paper will emphasis on H.323 and H.263 standard,especially H.263 algorithm and its optimization methods. The selection of DSP is also present in this paper. In chapter 1 I introduce the foreground of ip video phone and its construction. In chapter2 I introduce the H.323 standard. In chapter3 the performance and construction of TM1300 is depicted.. In this chapter PSOS+ OS is also introduced. Chapter4 will emphasis on H.263+ standard and mainly introduce the motion estimation DCT and Quantization.,ect.. In chapters optimization methods is depicted in detail on TM1300 and some optimization methods are introduced.and in chapter6 I will introduce the system implement and its performance.