Design And Implementation Of TS Subtitle Server Based On UDP

The transport stream subtitle Server is a digital device which combines (MPTS)and real-time digital graphic information superimposed in TV program transmission.Traditional TS subtitles server system consists of computer, subtitle card and software,using the ASI board for data input and output. Due to the ASI board has limitations ofdata transfer rate, the server can only increase the copy number of broadcast through amulti-card portfolio. However, the whole process can be enhanced by Gigabit Ethernetdata port for data input and output, which reduce the steps to deal with themulti-channel data access aspects of running, thereby improving system stability,reliability, and cost savings. This project designed and developed a system of serverhost-based Gigabit Ethernet data port, UDP protocol to send and receive transportstream subtitles server system software to achieve multi-channel digital video signalsubtitle overlay function.This thesis design and develop a subtitle server consists of3parts: data output anddemultiplexing MPTS; Single program subtitles superimposed processing; multipleprogram multiplexing and data output.Data input and MPTS demultiplexing includes data input, MPTS systemdemultiplexing, schedule processing. This section complete port issue using UDPprotocol and Microsoft technology to solve the problem of data input, MPTS andsubtitle data obtained from the network port. Furthermore, using DVB (Digital VideoBroadcasting) standard to solve the the the MPTS system demultiplexing problem,extracted SPTS (single program transport stream) from the MPTS. Through SPTSpre-include and error detection, then formally included in the operation to realize thescheduling processing the Subtitle server program source.Single program subtitles superimposed processing consists of a single programdemultiplexing, video decoding, subtitle superimposed aspects of video coding, audioprocessing and program multiplexing. This part use MPEG-2standard and Intel IPPlibrary to resolve the video ES program to YUV image demultiplexing, decoding, encoding, a program multiplexed, therefore realizing audio and video ES (elementarystream) from the SPTS to achieve the SPTS、audio、video ES and YUV imageconversion. The fixed algorithm YUV picture converted to RGB images, useprogressive scan superimposed the RGBA subtitles pictures to RGB video pictures,realizing superimposed subtitles server.Multiplexing and data output of the multi-program system consists ofmulti-program system multiplexing, data output and so on. This section use the DVBstandard to solve the problem of multi-channel programs superimposed subtitlesmultiplexing, realizing multiple SPTS system multiplexing into MPTS; using UDPprotocol and broadcast rate control algorithm, to solve the problem of data output toachieve from the network port push MPTS at a steady rate.After testing the whole TS subtitle server and modules stated above, the resultshows that all the modules is able to function normally over48hours when processing6independent programs, which indicates that this TS subtitle server system is valuable inbusiness terms.