H.264 Video Encoder Based On TMS320DM642

Video monitoring can be directly perceived through the sense. Because of its richness and convenience, it is used widely by safety guard, product management, and so on. It plays an important role in the environment monitoring. The video compression is key technology of video monitoring, and video codec is one of the most important core modules for a multimedia application systems. H.264/AVC is newest video coding standard of the ITU-T Video Coding Experts Group and ISO/IEC Moving Picture Experts Group. The H.264/AVC video coding standard can achieve considerably higher coding efficiency than previous standards. Due to the advanced compression performance and the"network-friendly"nature, H.264/AVC will be the next generation of"industry-leading"video coding standard.This paper will make an emphasis on research of key technologies and the implementation of H.264 video encoder based on DM642 platform. At the beginning of the paper , we analyse the complexisity of video encoder and different parameters which have an effect upon encoder performance. According to the fact that video scene is smooth , little motion, has many background blocks, method for detecting skipped macroblock ahead of discrete cosine transform, quantization and context adaptive variable length coding and early termination algorithm are improved. A fast mode decision algorithm for Intra prediction in H.264/AVC video coding is proposed based on Prediction Mode Histogram. Experimental results show that the algorithm increases the speed of intracoding significantly with negligible loss of peak signal-to-noise ratio. Secondly, we discussed the method that T264 encoder based on PC is transferred to DM642 platform, then the application optimization in DM642 embedded system was made by the following sides: application architecture,memory system,Cache optimization and EDMA. After those steps, not only the encoding performance is improved , but also many skills of software development about DM642 were summaried.