Design And Implementation Of Small Graphics Optimization Based On Chip Of Set-top Box

Digital set-top box includes hardware platform and software system. Theformer processes audio and video decoding, and the later deals with the userinterface, reproduction of television image, the service of data broadcasting andinternet access. Both of them determine the user experience. All of the mediarequire real-time performance. For example, graphics engine run not only “fast”,but also “faster”. However, simply to pursue the performance improvements, theconfigure of hardware requires high quality. So cost is not optimal. In addition tographics engine, small graphics are processed with software and the performancewill be better. SGO (small graphics optimization) is an optimization for smallgraphics, which enriched TDE (two dimension engine,2D graphics accelerationengine) interfaces. There are three interfaces, including filling, moving, zooming.Firstly, this paper analyzes the demand for manufacturers of set-top box. Andthen, Hisilicon HD chip Hi3716C is decided to be used as its development platform.The paper analyzes stream processing of Hi3716C, and especially, graphics moduleis introduced in detail. After that development and testing environment is built inneed. Secondly, algorithms about graphics operation are researched. According tothe actual situation, SGO only deals with the rectangle as object, so polygonclipping algorithm can be simplified, and line scan filling algorithm is optimized.Then, the basic functions including filling, moving, zooming of SGO are realized inC language. What’s more, key processing, transparency handling with the basicfunctions are also can be used. In the additional transparency processing operation,classic porter/duff algorithm is implemented; moreover additional user-definedparameter functions are realized, so SGO provides more space to users with greatersecondary development. Finally, reference process of the secondary developmentfor users is involved, and the testing results about features and performance of thethree interfaces are provided. The testing results show that the interfaces can satisfythe above functions, and the performance compared with TDE is improved.