Software Design Of Multiple Windows' Monitoring System Of Digital Television Based On DirectShow

The monitoring systems of safety broadcasting of domestic TV stations, staying generally on the phase of analog monitoring of digital TV, need digitize reform exigently. On the base of investigating deeply into the safety broadcasting of domestic digital TV stations, the paper designs a multi-windows'safety broadcasting monitoring system of digital TV with DirectShow, which realizes the digital monitoring of safety broadcasting. It processes real-time TS with software, which saves hardware cost greatly and integrates the function of digital code monitoring.Firstly, the development of the monitoring systems of safety broadcasting of domestic TV stations is investigated. On the base of investigation, two main functions should be implemented: the monitoring of audio and video and the monitoring digital code.Secondly, the design and implement of monitoring system of digital TV based on DirectShow are described, including the design of Filter and the design of application. In the aspect of the design of Filter, two Filters are designed: data source Filter of TS(TsSourceFilter) and monitoring Filter of digital code(PsiSdtFilter); the TS demuxing, video decoding, audio decoding modules are implemented by the Filters of Elecard corporation; video and audio rendering modules are implemented by the Filters of DirectShow SDK. In the aspect of the design of application, the design of application is divided into four modules: the building of FilterGraph, the monitoring of video, the monitoring of audio, the monitoring of digital code; then the design and implement of the four modules are introduced. Moreover, the building of FilterGraph is the base of other modules. Therefore, the building of FilterGraph is the most important part of the design of application.At last, it is the debug part of system integration. The test items, test measures and tools and the performance test of the system are described, and the test result is analyzed. Furthermore, it explains the aspects waiting to be perfect.