Migrating And Optimizing The Video Encoder And Decoder Of MPEG-4 On DM642 Processor

With the fast development of modern information technology, the new standard of the video compression appears constantly. MPEG-4 is a new ISO/IEC standard developed by MPEG (Moving Picture Experts Group), the committee that also developed the standards known as MPEG-1 and MPEG-2. The whole name of MPEG-4 is ISO/IEC 14496. MPEG-4 is more efficient of the video compression and content-based interactivity. Now, many companies are researching and developing the application of MPEG-4. The field of product involves communication of picture, video monitor, digital TV, many products are implemented by multimedia processor which is programmable.Firstly, with the development of the video standard, we summarize MPEG-4 encoder and decoder; introduce the framework of video encoder and video decoder. And then we analyze main technology, for example, half-pixel search, block matching, DC/AC coefficient prediction, the mode of intra and inter, and research the sharp encoding/decoding, motion estimation and compensation, still texture encoding/decoding especially.Secondly, the paper introduces the DM642 processor, describes the CPU structure,assemble instruction,in-chip memory and pipeline in detail. Then the soft development environment and the method of the DSP program's optimization are introduced.Combined with the previous content, implementation of MPEG-4 Simple Profile's VOP and the migration on DM642 are introduced. Some optimization methods are imported to realtime applicationi. Choosing proper parameters of the CCS is fast and effective method, and using EDMA between in-chip memory to memory makes CPU be busy working, also, puting some frequent functions into L2 memory is a good idea. After analysing P-VOP's encoding flow of MPEG-4, improvement of P-VOP's encoding flow is introduced, and this method can increase...