The Research And Application Of H.264/AVC Video Encoder Based On Embedded Platform

H.264/AVC becomes a new generation of international video coding standard for its coding efficiency and good adaptation to the network. It absorbs the experience of video coding standards, and adopts a lot of advanced coding techniques. Under the same image quality, compared with other video coding standards, the compressed bit rate of H.264/AVC is only 1/2 bit rate of H.263 or MPEG- 2, and 1/4 of bit rate of MPEG-2. With the emergence of open source code and a number of commercial codes such as JM, x264, combined with enhancing the ability of the professional video processing chip, H.264/AVC has gradually moved toward the fields of practical application. In the field of multimedia information distribution, video surveillance, video conferencing,IPTV, HDTV etc., the products with H.264/AVC video coding standard all have appeared.In this paper, the core algorithm in H.264/AVC is analyzed in depth, the module of which time complexity is high in the algorithm is optimized; the design idea and implementation theory of video processing system based on ARM+DSP architecture is researched; an improved proposal for the stability of TS transmission is proposed; and the real time digital multimedia encoder MVEC (Multimedia Video Encoder) based on H.264/AVC is realized. Mainly completes the following works:Firstly, the development history of the video coding algorithm is described, as well as the mainstream development platfonn situation of encoder is analyzed in this paper. The structure and the encoding process of H.264/AVC encoder is described in detail, the complexity of its core module is researched and tested in order to determine which module need to focus on optimizing.Secondly, the optimizing plans and strategies which reduce the complexity of the algorithm and save the time of coding for the time-consuming module of H.264/AVC are proposed in this paper. The following aspects are mainly optimized:according to the degree of the pixels change in the internal macro block, the selection strategy to the fast prediction mode in the frames is introduced; according to the prejudge of SKIP and the reference of the motion characteristics of the corresponding macro blocks, the selection strategy to the fast prediction mode between the frames is introduced; according to the selection strategy of the macro blocks to the prediction mode between the frames, the fast adaptive cross searching algorithm based on different searching radius is introduced.After completing the research on H.264/AVC standard algorithm, this paper focuses on the design of software and hardware architecture of the H.264/AVC encoder-MVEC based on the ARM+DSP platform. The choice of the MVEC platform, the selection of the chip, the design of software architecture of ARM, the design of software architecture of DSP is researched in detail and in depth.For the transmission of the video stream, analyzes and compares the two current mainstream transmission plans-TS and ISMA, and proposes a solution named PCR correction (anti-jitter) for the jitter phenomenon of TS caused by transmission multiplexing in order to improve the stability of the coding transmission system in this paper.Finally, makes a brief description on development environment and implementation process of MVEC, shows the outcome, and describes the application of MVEC in practical situations taken multimedia information distribution system as a case study in this paper.