Research Of AVS Video Encoding/Decoding Standard And Realization Based On DSP

The digital video multimedia technology receives increasing attention for its high quality and high error resilience. But it contains enormous data and couldn't be supported by current network bandwith. Compression must be done to meet the requirements of storage and transport. So video coding technology is a key in the digital video multimedia technology field. AVS is a video/audio encoding and decoding standard developed by China independently, and it is one of the most advanced video compression standards that are available. It has many good advantages, including good performance, low complexity algorithm, low patent licensing fees and so on. We have reason to forecast that AVS can find many application fields.As one kind of special data processing chipes, DSP has been wildly used in video encoding/decoding technology field for its short exploitation period, flexibility and updatable features. Blackfin family DSP, which is developed by Analog Devices Inc. and Intel Corporation, is a fixed-point DSP product with high performance, and it is designed specifically to meet the upper computational demands and power constraint of audio, video and communications domain.It is significant in both engineering application and market value to combine advanced technique of AVS and stable DSP together which achieves a better video compression performance. This project is put forward in this background.The dissertation begins with the introduction of the basic theories and relative standards of video coding. And then it mainly researches AVS video coding standard, including main technology of AVS video standard, comparison between AVS video standard and other video coding standards, the IPR(Intellectual Property Rights) status and the development prospect of AVS video standard, etc. It also introduces the properties, structure and development environment of Blackfin family DSP. Employing ADSP-BF561 EZ-KIT LITE evaluation board and AVS video standard, the dissertation designs the CODEC(Coder-Decoder) hardware platform. Relying on embedded ucLinux OS(operating system) and Blackfin cross compiling environment, AVS video CEDEC algorithm is transplanted to ADSP-BF561 platform.According to the properties of ADSP-BF561, the dissertation optimizes the AVS video CODEC algorithm invoking compiler optimization, DMA optimization, algorithm flow optimization, storage structure optimization and assembly instructions optimization. The optimization is concentrated on decoder optimization. Because the optimization of core decoder module is a key to improve the speed of decoder. The dissertation mainly analyze and optimize the core modules of decoder, including sub-pixel interpolation, integer transform(inverse transform), deblocking loopfilter, etc. Test results show that the optimizing methods put forward in this dissertation significantly improve the efficiency of AVS decoder, and the subject quality of decoded image is good. It also meets the requirements of the design.