Research Of H.264 Coding Standard And Optimization Design Based On DM642

H.264 is the newest video coding standard which is designed by the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. H.264 can save approximately 50% bit rate at equivalent picture quality relative to the existing standards. Due to the advanced compression performance and the "network-friendly" nature, H.264 will be adopted over a broad variety of applications such as video telephone, broadcast, streaming services, storage and so on.In this paper, H.264 standard is researched and expatiate the basic algorithms of every part of the encoder. According to the analysis of the old methods, an optimized method of nine 4×4 luma prediction mode was proposed. The method is based on most-probable character, temporal&spatial character and the neighborhood prediction mode character. The experiment result shows that this method is able to achieve a reduction up to 50% time for I frame encoding, with nearly equivalent encoding performance to the original RDO full search method of H.264 reference software. This paper also analysises and compares the excellence and shortcoming of five fast motion estimate search methods separately, and optimized methods of H.264 encoder based on DM642 are designed. It includeds how to migrate JM86, introduced about DM642 and hardware, optimization of C language and linear assemble language, utmost utilize cache on DM642 and memory assignment. Experiment result shows that encoder has better performance through these methods, encode speed can achieve about 14~16 frames per second.