H.264 Motion Estimation Algorithm and Application of hierarchical coding
|School||Huazhong University of Science and Technology|
|Course||Microelectronics and Solid State Electronics|
|Keywords||H.264 Motion Estimation Sampling optimization Scalable Coding|
Information needs of modern multimedia rapid growth , thanks to the information source processing technology and network communication technology . The video coding technology is one important area . Latest H.264 video coding standard , because the compression rate and the advantages of network transmission is considered to be the next major video compression coding technology . The H.264 encoding complexity is the impact on its large-scale application of the bottleneck. How to maintain the advantages of H.264 encoded reduce its complexity and diversity make for great application environment still has a wide range of adaptability in order to enhance the practicality of H.264 coding standard is our problem to be solved . This paper studied the H.264 standard video encoding process , the focus of H.264 encoding part of the complex that is the highest principle of motion estimation and summarizes the current major motion estimation algorithm, test compare their performance . Then the H.264 standard can be extended hierarchical coding techniques . By analyzing the process of motion estimation in H.264 , discovery rate -distortion cost of distribution and macroblock partition size and the relationship between the reference frame is proposed based on sampling optimized fast motion estimation algorithm . The algorithm predicted search starting point , and then the multi-precision sampling searching , and then a fine search multiple templates , and finally to 1/ 4 pixel block diamond search . Sampling search combines video and summary of relevant rules, select adaptive search templates and candidate search point , and in a few steps to introduce a number of new search for adaptive threshold is used to determine the optimal solution in advance or early exclusion bad solution . Then test the algorithm with full search method and the classic fast algorithm uMHexagonS algorithms. The results showed that , compared to uMHexagonS algorithm, the proposed algorithm coded in maintaining image quality of the premise, the estimated average speed of its movement by 32 %, and has a strong versatility. H.264 video coding system to adapt to the network environment and the quality of service a variety of code stream . This paper will present a fast motion estimation algorithm is applied to the system , and adding predictive coding mode between layers of measures to reduce the complexity of hierarchical coding , test results show that hierarchical encoding speed by 20 % or more.