Realization And Optimization Of AVS Video Decoder Based On TMS320DM642

The second part of Audio and Video Coding Standard(AVS) which developed independently by China, has been authorized as the national standard in March 2006. Compared with the other prevalent international video standards, AVS has three advantages: high performance, simple computational complexity, and low patent costs. At present, lacking of feasible encode and decode solutions, the application of AVS has encountered some obstacles. Therefore, after researching on key module, an AVS decoder solution based on TI TMS320DM642 is presented. The optimized decoder can decode at speed of 35frame/s for D1 resolution test sequence, which can satisfy the requirement of real-time, for example, video monitor or video meeting etc.Firstly, the thesis summarizes the main method in video coding domain, provides an introduction of the researching history and current status of international video compression standard. The frame and hierarchy of AVS decoder and encoder is presented, the key module algothrim is analyzed and researched, besides, a comparison between AVS and MPEG-2, H.264/AVC is presented.Second, research has been done on the loop-filter module which impacts video quality of encoder and decoder. The reasons of block-effect in video coding and the method of filter are summarized. After the analysis of the adaptive loop-filter of AVS, a new loop-filter based on block edge has been presented, what's more, the time-adaptive loop-filter is presented which can be applied to AVS decoder.Third, the AVS decoder source code has been optimized and repotted from PC to DSP platform successfully. The software and hardware platform has been introduced, the decoder mechanism is designed and AVS decoder source code which offered by AVS work team is repotted to DSP platform. Subsequently, the optimization method is summarized at program level, algothrim level, language level respectively and the data of decoder performance is informed.The final part concludes this thesis, points out the direction for further research and improvement, and looks forward to the bright future of AVS application.