Optimization And Realization Of AVS2Viedo Decoder Based On DSP

With the development of multimedia technology,video codec,as the foundationof multimedia technology, has also been rapidly development since the1980s, Theinternational community formulated video compression standard MPEG and H.26x.AVS is China’s audio and video standards with independent intellectual propertyrights, which has many advantages,such as its framework and performance aresimilar with H.264, but complexity is much lower than H.264. DSP is a dedicatedmicroprocessor for digital signal processing, which are particularly suitable for audioand video codecs. This article is mainly to achieve the AVS2video standard decoderand ultimately can achieve real-time decoding based on TMS320C6678hardwareplatform.The main research contents are as follows:Firstly, I expound the necessity and the possibility of video compression andintroduce the development process of the international video standards and thenational video standards. To illustrate the necessity of formulating video standards aswell as advantages, comparing the AVS and H.264in respect of quantizationtransformation, intra prediction, inter prediction, the entropy coding, the loopfilter.Secondly, all the key video decoder technology is be analysised in detail. Adedetailed description of the hardware platform used in this article is be expressed,which includes the process of development, characteristics, overall architecture, thecomposition of C66x corePac, data channel,on-chip memory, instruction set, EMDA,etc and laies the foundation of transplanting video decoder to TMS320C6678and itsoptimization. Making a simple introductiong of development tools CCS5.3and DSPprogram development and optimization process.Finally, Transplanting the video decoder to the DSP based on the analysis of thevideo decoder and the performance and resource of TMS320C6678.In the process oftransplanting, the following work to be done: specification data structure, real-timeprocessing, deleting redundant function, delete or modify the function which is notsupported by DSP platform, etc.After, The program is be optimized in respect of Clanguage, algorithm and DSP platform. In terms of C language level, loop structureand function calls, data structure is mainly be optimized; In terms of the algorithm level, overall structure of code, the processing of all zero block, motion compensationis mainly be optimized; In terms of DSP platform, the compiler, the CACHEmechanism, the storage space, EDMA, intrinsics function is mainl be used to optimizethe program. Finally realizes the real-time decoding decoder for D1(720×576).Finally using multiple test sequence to test decoder, The experimental resultsshow that the AVS2decoder is implemented on TMS320C6678and the average videodecoding speed reaches30frames per second approximately.