Design And Implementation Of AVS Video Decoder Based On DaVinci Technique

MPEG-4, h.264 and AVS is a new generation of audio video coding standard, they are always the hot research of every country's academia and industrial circle. AVS is a audio video coding standard, which constituted independently by our country. It has high compression ratio, high quality and relatively lower complexity of hardware implementation, which are suitable for requirement of multimedia and storage application over broadband, cable and wireless networks. As the evolution of the third generation of mobile telecommunication techniques, the research on implementation of AVS decoding and playing on digital TV and IPTV is becoming more important and urgent, and it has important theoretical and practical significance.By deep study on embedded and digital image techniques, the design scheme of AVS video decoding, which based on the embedded Linux system, is presented. The system hardware platform uses the embedded microprocessor of Davinci, which based on the dual-core architecture. According to the requirement, software platform uses embedded MontaVista Linux system. The paper makes a thorough analysis of development process of AVS, development survey of embedded system and embedded Linux, features and advantages of AVS video coding standard. On this basis, the general framework of software and hardware for AVS video decoding is designed. According to the requirement of video decoding and playing, the Davinci software framework is selected for the hardware platform, and the developing environment is constructed, includes: building cross compile developing environment of embedded system, analyzing the booting process of Bootloader, implementing the transplantation of Bootloader, and aiming at TMS320DM6446 target board, completing the kernel configuration and transplantation of MontaVista Linux system. The software design of AVS video decoding includes: according to the decoding framework and flow, designing AVS decoding algorithm, dividing the functional modules of decoding, optimizing the decoding algorithm generally in C language level, according to the interface standard of xDM algorithm, encapsulating the codec library of the decoding algorithm, establishing the DSP Server and do the configuration of Codec Engine. After completion of design and integration of AVS video decoding algorithm, the video playing program of application layer, which run on the embedded platform is designed, and the playing process is tested.The test results of the decoding algorithm's codec indicates that the AVS video test file could be decoded and played in real time under cooperative work of software and hardware. The decoding and playing effect has reached the standard definition of AVS. The codec has many characteristic, such as easy to update, short developing period and so on, which are suitable for IP set-top box, portable media player, video conference terminal and monitor terminal. Its application area is widely.