A Research On Inter-Frame Prediction Algorithm Of AVS And DSP Implementation

Fast coding algorithm is an important technology for improving video quality, AVS(Audio Video coding Standard), as a new advanced video coding standard proposed by China independently with a good performance and a low complexion in the application of high-definition video and online multimedia. This paper introduces some algorithm optimization on inter prediction of AVS based on a project problem, and do some optimizations in DSP embedded system to make it more proper for application. This project uses the platform based on TMS320DM6446 (Davinci) which is developed by our laboratory to run AVS coder, the emulation result shows that the frame rate improves about 25 times compared to the original C code.This paper is proposed some research for real-time and high precision request of application background. What we did include three aspects as follow:First, based on some theoretical support and reading a lot of correlative research productions of national and international, we improve the integer pixel motion search algorithm in inter-prediction part which costs the most time in AVS standard, and the result indicate that this algorithm just needs search about 20% point compare to the original algorithm in integer pixel motion search process, expedite compute speed, at the same time, there isn't obvious effect for image quality after processing.Second, this paper discusses how to implement this standard on PC. Because the test code cannot achieve practical application of the requirements, the research team has developed a real-time encoding code own by analyzing the code structure and the standard.At last, this paper proposes how to optimize the code in DSP. Because of the limited memory resources, the following methods are applied to the program of the encoder to improve the efficiency of TMS320DM6446: Cache optimizing, rational allocation of storage space and adopting DMA. Finally, the efficiency of DSP code has been improved significantly.Through the method above, the code developed by ourselves can run accurately on TMS320DM6446, and the frame rate reaches 13 fps. For the DSP on the further development of video compression algorithm, it is of important significance and is conducive to AVS algorithm in the DSP to achieve real-time.