Implementation Of AVS Evcoder Based On TMS320DM6446

The first Chinese audio-video coding standard AVS(referred to "Information Technology Advanced Audio and Video Coding" standards)has become an increasing concern by virtue of its advantages of efficiency, complexity and autonomy.The standard has reached the international advanced level both in technique and in performance.However,industrialization of AVS should be supported by an excellent processing platform.TMS320DM6446 (based on Davinci technology),the latest embedded video chip from Texas Instrument Corporation in American,is dual-core architecture,and has good capabilities of task-sharing and thread synchronization,higher parallel processing speed and lower power consumption.It also has video front and end processing system.Therefore,it is the ideal platform to realize AVS coding algorithm.This dissertation discusses the implementation of AVS coding algorithm based on TMS320DM6446,and the main works and achievements are as follows:The core technologies and features of AVS are analyzed,and the various differences between AVS and the international video standard—H.264/AVC are compared carefully.Next,through analyzing the advantages and disadvantages of the reference model of AVS—RM52J,an implementation scheme of AVS encoding algorithm in C language is set up,which combines the merits of RM52J and T264,the reference model of H.264/AVC.Especially,the C language codes of entropy coding module and loop filter module are programmed,and the performance and bit stream of the whole system are debugged.Lastly,the encoding and decoding tests show that the coding efficiency of new AVS code is five times than that of RM52J,and the generated bit stream is correct and the coding quality is good.In this paper,the characteristics of architecture and performance of TMS320DM6446 chip are studied,and the use of Code Composer Studio (CCStudio)—TI's DSP algorithm development environment—is described. Furthermore,this paper has realized the transplantation of AVS encoder based on C64x+ DSP platform of TMS320DM6446 and has discussed the optimization of the DSP algorithm,involving the use of profiling tools of CCStudio,internal memory allocation of DSP,linear assembly,and cache performance optimization, and so on.In addition,video format 4:2:2 to 4:2:0 conversion using EDMA is discussed in details.Through verifying,the optimized algorithm is more than 26 times in encoding performance than the non-optimized.Finally,the paper studies TI's eXpress DSP algorithm standard and Codec Engine framework and explains how to design the video coding algorithm based on the ARM+DSP dual-core framework.Video application(ARM side)running upon the Linux operating system calls the remote server(DSP side)AVS coding algorithm to complete encoding operation by starting Codec Engine.Moreover, the main flows and modules of application level program are given,and configurations of application and server and the remote tracking method are presented.It can be seen that the paper covers all major sectors of achieving AVS encoding algorithm on TMS320DM6446.It may bring efficient references for improving system functions and enhancing system performances in the future.