Research And Relization Of MPEG-4 Algorithmic Optimization Based On ARM Platform

In recent years, multimedia applications have gradually extended into many fields. While doing researches on the theories of new advanced compression technologies, people are paying great attention to putting these theories into practical applications. At present, with the capability of preserving high image quality under low bit-rate, high compression rate and low computation complexity than other Profiles, MPEG-4 Video Simple Profile has gradually become a new application focus on embedded equipment.MPEG-4 algorithm optimization is a new application of MPEG-4 video decoding technology. The studies may directly accelerate MPEG-4 applications and reduce the requirement for platform. The resource of entire systematic hardware platform has been optimized. MPEG-4 software decoding has much research significance and high commercial application value with ARM platform.With full understanding MPEG-4 standard, optimization the MPEG-4 performance on ARM platform is carried out. Firstly, the MPEG-4 performance algorithm in ARM926EJ-S platform is analyzed and tested. The strategy of optimization includes:1. The MPEG-4 on the general C layer has been optimized. The method of "peep- hole optimization" in compile principle and some general optimization strategies are adopted.2. The data flowing of MPEG-4 standard has been analyzed, and combining the Cache performance of ARM926EJ-S, the global optimization for data flowing is carried out.3. Each function module of MPEG-4 has been analyzed in detail. Some functional modules, such as the data stream decomposing, IDCT, AC/DC prediction and the moving compensation are optimized.4. Considering the factors such as DMA and Cache, systematic optimization for the algorithm of MPEG-4 has been carried out on ARM platform.In this paper, the pixel moving compensation of the MPEG-4 standard is tried to be improved, and the new method is tried to copy the image when doing with the pixel moving compensation. In addition, the AVI file is composed and the synchronization of sound and video is achieved primarily.Experiment shows that although it is based on ARM platform, with various algorithm optimizations, the speed of MPEG-4 video decoding may be reached to 38 F/s. The system has reached high performance and playing speed, which has much application value.