The Design And Application Of Embedded Graphic User Interface For Digital TV Set-Top-Box

Embedded graphic user interface is the dialogic interface between embedded devices and users. As embedded devices are used widely in the ordinary lives of people, the requirements of high performance of embedded user interface is demanded increasingly. So, the research of embedded Graphics User Interface which is the key technology of embedded system is very important.Set-Top-Box is a representative embedded device. It is a network terminal which is connected with digital television; it is used for transforming digital signals to analog signals. After decoding the digital constringent video and audio signals, it will engender analog video and audio signals. Consequently, it can provide high quality television program for audiences. It covers demodulation technique and decoding technique which are the key technique of digital television. As a result, developing Set-Top-Box is good propulsion of our DTV industry.This project regards the development of a digital satellite set up box as the background, does some research and practice of embedded GUI, aiming at implement of a GUI system which is used by the developers of user interface programming. And this GUI system must meet the main requirements of the functions in the condition of the hardware and software in the STB.After the holistic analysis of the developing modes and the implementing requirements of the whole STB system and the GUI system, this paper gives the unitary design of this GUI system. In the first place, it gives the design method which based on modules, and divides the GUI system into 3 modules which respectively are graphics engine module, key mechanism module and GUI object module. Then it gives the relationship of each module and the place of the GUI system in the whole STB system. Secondly, it analyses the design and implement of each module respectively.In graphics engine module, we firstly study the OSD device engine, and bring forward the design method of the graphics display memory, lastly implement the basal drawing and the work of bitmap. In the key mechanism, we adopt the scheme to our whole STB system, such as, the work mode is client/server mode which is implemented by thread, and the GUI system adopts the mechanism droved by message. In the GUI object module, we give the design mode of dialog box and controls.Finally, we bring forward a design method of digital television user interface which has clear hierarchy. Then we implement the main menu in our GUI system.In practice, this GUI system can meet the demand of graphics user interface programming on the whole.