Research On Video Control Subsystem Of Subway Multimedia Information System

ABSTACT: In the subway there are two multimedia systems:the passenger informa-tion system (Passenger Information System, or PIS) and the video surveillance system. With the awakening of awareness of passengers-first and the development of multi-media technologies, Vehicle PIS should be able to provide more detailed information under emergency situations such as a fire or terrorist attacks and thus it is required to be equipped with high safety ensurance ability. As the video surveillance system is able to provide abundant visual information with a high accuracy of alert functionality, this thesis combines the two systems together to create a subway Multimedia Information System, or MIS. In short, MIS is a digital IP information network system applied on a subway train, targeted for both passengers and the staff.Current PIS system provides passengers with abundant news and entertainment programs. And the video surveillance system provides the staff with real-time video surveillance. A MIS system is two systems combined. Video Control Subsystem, an important part of the metro’s MIS system, has been implemented in this thesis, in an attempt to to meet passengers’demand for up-to-date and HD news programs, as well as the staff’s demand for multi-view HD surveillance videos.The DTMB terrestrial digital TV broadcasting, which has been around for less than4years, is chosen to be a source for real-time TV programs. The Integrated Control Unit, the core of the subsystem, is built upon a compact, low power consumption, and inexpensive ION platform. Application-level softwares have also been designed and realized. Leveraging the integrated graphics processor to accelerate video processing, the unit is able to process videos with definition as high as720p. Stable and good test results have been achieved.The thesis focuses on the concrete realization of various functional modules of the video control subsystem, which include:1) Receive DTMB terrestrial digital high-definition television broadcasting data, display it, and forward it to the carriage clients, realizing real-time broadcast of TV programs. The staff can also switch to different channels, available from DTMB, to ensure abundancy of programs.2) Local video playback and transmission is implemented. The subsystem can store a variety of video clips, such as commercials and government propaganda programs. The staff can choose sent them to displays in passenger compartments.3) Multiple surveillance video streams can be received and stored in the subsystem at the same time. The staff can also be able to view multiple video streams. And the subway station control center will be able to view those video streams either.