The Research And Realization Of AVS Video Encoder Based On TMS320C6474

Multimedia technology occupies a very important position in the development ofinformation technology and video encoding technology is one of the coretechnologies of multimedia. How to transmit more information in the case of limitedbandwidth needs further study. Only with the use of more efficient and more rapidcoding algorithm can we respond to continuously developing encoding complexityand the increasing amount of video data. Currently, the main video encodingstandards are MPEG series, H.26x series and AVS. AVS is China’s firstself-developed video encoding standard with independent intellectual property rights,which achieves lower complexity but the same performance as H.264/AVC. At thesame time, the hardware platforms which support video encoding implementing areconstantly in development. DSP is very suitable for the develop of embedded audioand video as it has computing accelerate units such as multiply accumulator, and is ofhigh flexibility. AVS standard video encoder is implemented on TMS320C6474multimedia processing platform, and optimized to close to real-time coding speed thatrequires25frames per second. The main research content and work of the thesis areas follows:First, the characteristics and key technologies of AVS coding standard areanalyzed, and the AVS standard is compared with MPEG-4AVC in various aspects.The corresponding deletions and modifications for DSP platform transplantationbased on the analysis of the redundancy and insufficient of code functions and datastructures in AVS standard code RM52i are done, focusing on the rewrite andoptimization of entropy coding algorithm and the function of write code stream. Codesize and coding complexity are reduced on the basis of core functionality of encoderrunning correctly on the DSP platform.Secondly, the development process of DSP and the evolution of TI’s DSPproducts are introduced, which focuses on the TI C6000series. Taking all factors,TMS320C6474is finally chosen, and then the details of its features and on-chipresources are introduced. And the process of DSP development and optimization isintroduced briefly as well as the development environment Code Composer Studio(CCS). Finally, the optimization on DSP platform of encoder combines the characteristicof AVS encoder with the performance characteristics of TMS320C6474. The on chipspace is allocated reasonably based on the space consumption of encoding process;the codes of related functions are replaced with DSP LIB and intrinsics functions;open Cache and cooperate with DMA channels to reduce the time-consuming of dataaccess; the compiler optimization options are used in order to achieve the bestperformance.The final encoding test results of video sequences show that the AVS encoder isimplemented on TMS320C6474and the average video encoding speed reaches20frames per second approximately, close to the real-time coding requirement which is25frames per second.