Research And Realization Of AVS Real-time Decoder Based On DSP

AVS (Audio and Video Coding Standard),the second part of which has been authorized, is the standard of video and audio developed by our country independently.It has the superiority of simple computational complexity and low patent licensing fees.At present,the application of AVS in the field of Video and Audio domain has encountered obstacle ,because of short of feasible encoder and decoder solutions, so the research on AVS1-P2 has become necessary to solve the problem. The purpose of the thesis is to improve the speed of frame to meet the request of real-time video displaying.At first,the algorithms of AVS1-P2 is studied,the characteristics of TMS320DM642 is analyzed the the methods of DSP to optimize Video are researched,establishing the foundation for optimizing decoder.The speed of every modules is the key factor in the process of optimizing the decoder.The improvement of the speed of decoder So the keystone is to provide solutions for the kernel specially with the purpose of improving the frame rate of decoder.Sub-pixel motion interpolation filter module reusing shareable samples not only simplifies the 1/4 sample interpolation algorithm,but also improves interpolation filter efficiency through using DMA parallel prefetching from the reference samples to improve access efficiency and using intrinstics to enhance counting efficiency.The optimization for the sub-pixel interpolation filter module has increased 7 frame/second for the decoder,which is best among all the modules.The establishment of shared memory system between Intra- Prediction ,Reconstruction, and In-loop filter has reduced the redundancy between the three functional modules and improved operating frequency. Different from the tradition,a new methods of adjusting the sequence of In-loop filter and architecture of decoder has come out innovatly.The parsing golomb module advising to read a word (32bit) but not a byte simplifies the method of parse prefix and suffix of golobm code.In addition,the following mehods are also applied to the program of the decoder:Cache optimizing,data transmission managing (adopt DMA), using intrinstics,and optimizing software pipelining.The result of the test proves that AVS1-P2 could meet the requirements of teal-time decoding through the optimizing methods above.