Study And Implement Of Video Encoder Based On Embedded System

In recent years, with the prevalence of 3G wireless communication, and the development of multimedia processing technology, digital video service has gained people's attention greatly. Real-time multimedia applications, such as videoconference systems, video monitor systems, HDTV etc., have been widely used. Although network environment and storage conditions have been progressing a lot, the bandwidth resource is still limited as far as the fast growth of multimedia applications is concerned. Therefore, video codec technologies that can produce high compression ratio and high picture quality have been a hotspot issue in multimedia field.By comparing the recent developments and research, there are two different methods to implement video digital transmission and digital storage. One method is to use PC. The other method depends on the embedded system. Both of the two methods have their own advantages respectively. PC based method has higher coding rate and is easier to implement. Method based on embedded system becomes the hotspot because of its convenience and small consumption.H.264/AVC is the latest international video coding standard. It is designed and developed by a Joint Video Team (JVT) consisting of experts from ITU-T's Video Coding Experts Group (VCEG) and ISO/IEC's Moving Picture Experts Group (MPEG). Compared with the former video codec, there are many advantages in H.264/AVC video encoding. The efficiency of encoding is higher about 35% to MPEG-4.It is higher about once to H.263.This paper focuses on the realization of H.264/AVC encoder on the embedded processor Intel XScale PXA255. According to H.264/AVC profile and level suggestion and the character of embedded system, H.264/AVC Baseline profile is chosen. First this paper introduces the development of hardware and software on PXA255 in brief, and then focuses on the main character of H.264/AVC: intra prediction, inter prediction, integral DCT, quantization, CAVLC encoder, partitioned structure. And then it has the character of network friendliness. In contrast to the encoding structure of H.263 and the programming module of JM10.1, the reference software of H.264/AVC, it develops the software encoder of H.264/AVC with embedded Visual C++.At last it compares this encoder to the JM10.1 Baseline Profile encoder by experimenting with the standard video sequence (foreman, salesman, carphone). At last it concludes: The implement of H.264/AVC video codec on embedded system is feasible.