Based On DSPs's MPEG-4 Video Compression Algorithm Research And Implementation

The modes of realizing video compression algorithms include software, ASIC chips and DSP chips. The mode of adopting DSP chips to realize video compression algorithms is the best one. The mode utilizes the digital signal processing function of DSP chips and software programming to realize video compression algorithms. The mode has many advantages, such as high compression ratio, good image quality and easy updating, etc. These algorithms can be applied to embedded systems.The basic task of this paper is to study how to utilize DSP chips to realize the MPEG-4 video compression algorithm and optimize the algorithm in some degree to meet the requirement of real-time video compression. This paper discusses the technologies of the MPEG-4 compression algorithm. The technologies include predictive coding, discret cosine transform and variable length coding, etc. Motion estimation affects the performance of inter coding and compression effect. So this paper proposes to adopt diamond search algorithm with better performance in several fast motion search algorithms. The motion module and the quantization module are improved to resolve their issues. In the course of improving the compression algorithm, the whole flow of the compression algorithm, the I-frame coding flow, the motion estimation flow, the P-frame coding flow and the motion estimation module have been designed in detail.Meanwhile, this paper analyses the VLIW architecture and the hardware resource of TMS320C6000 DSPs. The algorithm has been optimized by adopting the methods which include configurating memory reasonably, optimizing cache, using EDMA to transfer data and rewritting the critical code by using linear assembly. In addtion, The compression algorithm is tested by using the DM642 EVM board and the emulator. The emulation results show the performance of the algorithm is excellent, the image quality can meet the requirement of applications, the algorithm can realize real-time MPEG-4 video compression process, and it can be applied to real products.