Optimization Of H.264 Decoding On Embedded Linux

With the development of mobile computing,the application of video playing used in embedded system is increasing sharply. Among the variety of video coding technologies,H.264/AVC raised by JVT(Joint Video Team)became the standard in the industry circle for its good efficiency. But the high compress rate means more complex computation, so it's difficult to use H.264 on embedded system for its limitation of hardware computation ability. This paper gives a novel method of H.264 decoding based on embedded Linux on ARM.The key point of this paper is the realization and optimization of the H.264 Baseline decoder. All of the research is based on version JM10.2 of JVT. First, the main time-consuming functions and sub-functions of system were build by analyzing the complexity of video coding layer, and there proportion of the whole decoding process were calculated, those functions and sub-functions which influence the decode speed most will be optimized on different level. Then the general programming optimizing method and the special optimizing method for H.264 decoding were integrated to give the detail of optimizing method for the variable length code,reverse DCT transform and motion compensate part of the decoding process. At last, the detail scheme of H.264 decoding based on S3C2410 of ARM9 is given in this paper, including constructing environment for developing,reducing embedded Linux operation system,implementing device drivers,transplanting decode program from PC to ARM, etc. The result and discussion of simulation and some suggestions of improving the efficiency of decoding were given at the end of this paper.