Implementation And Optimization Of AVS Decoder Based On OMAP3530

AVS, which is our country’s second generation of digital audio and video decoding algorithm standard with independent intellectual property right, has a broad market prospect because of its high efficiency, low complexity, as well as many other advantages. State Administration of Radio, Film and Television has unified planning and has invited biding formally Taiyuan, Shijiazhuang, Changchun, Hangzhou, Nanchang where the application of AVS ground digital television will be available. Therefore it is vital to carry out the video multimedia terminal equipment algorithm about the AVS standards. This paper carries out AVS (DI) decoding system research and implementation based on a new generation of open platform for multimedia applications OMAP3530launched by TI Company, puts forward video decoding schemes, and finally come up with a decoder with real-time decoding ability. For the realization of AVS video decoding algorithm on the OMAP3530platform, this paper mainly completed the following three tasks:①Transplant AVS video decoder from PC platform to OMAP3530platform.In the initial stages of development, we need to transplant AVS video decoder from PC platform to OMAP3530platform first. Because the developmental environment of the two platforms is different, we should special attention to the following aspects during the transplanting process: library and header files altering; configuration of cmd and gel files; definition of global variables; the variables storage adjustment; variable storage space distribution, etc. out a video decoding scheme based on OMAP3530platform, design and package the decoder which has been successfully transplanted to OMAP3530platform.The video decoding scheme based on OMAP3530platform contains two parts:ARM, which is responsible for initializing and controlling DSP, and LCD video display, etc.; DSP complete the work of data processing. To realize ARM enable and control DSP, the decoders which has successfully transplanted to OMAP3530platform must be designed and packaged in compliance with the compilation of the video decoder XDAIS standard. That can ensure the ARM and DSP normal communication.③Optimizing the packaged decoder to achieve the real-time purpose. In the context of limited resources, and the insufficient use of DSP resources during the initial stage, the decoder transplanted to DSP is in low efficiency. As a result, various optimizations must be implemented to realize real-time decoding. This paper adopted C levels optimization first, including adjustments of the program structure’s algorithm, implement about various kinds of optimization to circulation codes, choose the best optimized option of c16x compiler, and the reasonable distribution of structure variables; Secondly, according to the VLIW and parallel mechanism of water features of C64X+, take assemble optimization strategy; Finally according to the reasonable allocation of storage space and adjust the code execution of the code order, the cache hit has been improved. Through a series of optimization strategy, the decoder can achieve the goal of real-time decoding on OMAP3530platform.D1format data stream runs well in the OMAP3530platform and tests ha showed that the rate of the Dlstreaming of AVS format can reach over25FPS. It is completely suitable for multimedia terminal decoding equipment.