The Research And Design Of Digital TV Set-top Box Based On SC2005

In recent years, with the accelerated digitization of China digital TV, digital technology has been used widely for application, using a digital television to watch program has become mainstream, However, many families buy there was no built-in TV to digital TV signal decoding the hardware structure and software structure, so need a middleware to accomplish the digital TV signal decoding, digital TV set-top boxes came into being. So design and develop meets the requirements of digital cable TV set-top box has great practical significance and market application prospect, the study of digital technology in the set-top box has a very high academic value.This paper study of digital cable TV system involves theory, including MPEG-2 and DVB standards, analyse the part of the MPEG-2 system about digital cable TV transport stream and reuse process, the DVB standard business information related to electronic program guide EPG service information parsing process. Based on the principle of digital TV set-top boxes and source decoder chip SC2005 internal resource and peripheral interface module analysis, established the source decoder chip SC2005 as the core of the hardware design scheme of digital TV set-top box, mainly complete transmission flow solutions for reuse, audio decoding, graphics, video encoding, audio DAC, and other functions, the decoder solution complex with entered of transmission flow, then respectively for audio decoding; hybrid coding output CVBS and S- video signals after the video information decoding and audio information after decoding through the DAC output channel stereo audio. In the operation of the set-top box, STB program clock reference or PCR jitter correction in precision to the set-top box to decode the video output image with the video output synchronized with the video encoder’s impact,the output image will fade and the black screen will appear, to eliminate the influence, through the study of PCR correction algorithm, designed the PCR correction module.Developing the project, the paper expounds SC2005 adopted by the main chip embedded real-time operating system including μC/OS-II and software development environment, made a comprehensive presentation of software architecture, and start the process of the set-top box and the task to create the key description. Finally, the electronic program guide EPG work processes are describle in detail, the development environment, implementation scheme, and proposes a novel appearance, powerful method of designing the EPG electronic program guide.Through testing and debugging of the system, the whole system of the set top box, search the channel quickly, accurate output program information, image is clear, proved that the scheme is feasible and advanced.