Research Of H.264 Video Code Technology

H.264 is the latest video coding standard in which some new coding techniques has adopted to achieve high coding efficiency. Among the techniques of H.264, variable block-size motion estimation utilizes seven block sizes to reduce the temporal redundancy between frames. In video compression, motion estimation plays a key role for reducing the complexity of the calculation. There are different impacts on the performance while using various search algorithms for motion estimation. Efficient algorithm can save more computing time and more search points. Many novel techniques are adopted in motion estimation of H.264.It basically includes the motion vector at quarter pixel resolution with variable block sizes and multiple reference frames. With these attractive characteristics, it can achieve more accurate prediction and higher compression efficiency. However, because of these characteristics, the complexity and computation load or motion estimation increase greatly in H.264.This paper firstly briefly describes the basic concepts and existing methods of video coding. Then, it briefly analyzes the technical characteristics of video coding. After that this paper introduces several existing classical Block-Matching Motion Estimation. It also analyses their strengths and weaknesses respectively. At last, it analyses the core algorithm of motion estimation-UMHexagonS which is used in H.264. In order to improve the lack of motion estimation algorithm, the algorithm was optimized. Experiment results show that the optimized UMHexagonS algorithm can achieve good performance not only in reducing the time of encoding and ME, but also in keeping the quality of the video.