Design And Realizing Of Multifunctional Video Server Base On FPGA

Digital TV system broadcasts pictures and sound base on digital signals. Digital signals are used in obtaining, generating, and disposing, transmitting, receiving and storing TV signals in digital TV system. The pictures quality of digital TV is as good as DVD, and there are no white specks or double image on TV screen in digital TV system. The programs are profuse for users to choose. Our TVs are going to enter the age of individuation and intercommunion because of digital TV system.MPEG-2 standard is a video and audio compress criterion which is applied widely all over the world. The standard only defined the decoding model, and then encoding and disposing signals were very free, because it was demonstrated well if the output of it could be decoded by the MPEG-2 decoder. The device which was introduced by this paper can broadcast three kinds of program sources including programs of satellite transmission, hard disk storage and internet, and it also can multiplex those three kinds of programs and broadcast them. The device can be used in both internet and DTV net. The design is able to broadcast local programs instead of rebroadcast that is relayed from another station when rebroadcast programs of another station. And it also can realize the real time exchange between internet programs and local programs. The device can scramble programs which make users develop conditional access operation. It supplies the function of ordering program. The video server can be used to record programs of satellite transmission or delay them. The hard core of the design is FPGA and DSP which shorten the time to market of the product.The development and research of digital TV were summarized in this paper firstly. The conception and design method of FPGA were introduced briefly, and characteristic of Hardware Description Language was mentioned. Thereafter, the MPEG-2 Systems Specification and parts of Video Specification were dissertated. The process of MPEG-2 multiplexer was dissertated, and then three conceptions about time were introduced include PTS, DTS and PCR, and the relationship between them was discussed. The functions of the video server and its position in digital TV system were mentioned and discussed. The hardware circuit of broadcasting board which was used in video server was introduced. The design of FPGA on the board was depicted emphatically. The holistic configuration of FPGA design was expatiated. The design of FPGA was introduced in three parts: broadcast local programs, broadcast satellite programs and record satellite programs. And then the FPGA system was separated into sub-module and expatiated severally. The sub-modules include signal inputting, DMUX, local programs broadcasting, MUX, seamless splicing and PCR adjusting. Thereafter test results of the system were described. Finally the advantage and the disadvantage of the design were mentioned.