Design And Implementation Of Control Subsystem Of The Digital Video Recorder Based On MPEG4

Limited by the technology, the traditional video record system employs magnetic tape as recording media. Magnetic tape, a one-off product which can not be copied repeatedly and replayed time after time, greatly restricts high quality preservation of video. With the development of the technology of semiconductor and digital storage, the digital storage of video and audio became reality. The digital video surveillance system, with DVR(Digital Video Recorder)as its core component, has the advantage of integration, digitalization, simple usage, intelligentization, net-work based control, is receiving more and more interests in security defense area and will be the substitution of the traditional video record system in the future.First, the background technology and development of the digital video recorder system were reviewed and the advantages of the DVR system were introduced. Second, an embedded digital video recorder system based on MPEG4 was designed and realized after extensive studies of the advantages and imperfections of several current digital video recorder systems. This system utilizes embedded SC2200 processor and Linux operating system as its hardware and software platforms respectively. The compression and decompression of audio and video are performed by the high-powered chip VW2010, which adopts MPEG4 as it's compressing arithmetic. Then the design and realization of the control subsystems of hardware and software were discussed respectively. In the hardware part, diagrams, principles and the ways of realization of every part were provided. For the software, two designs were provided. One is based on foreground and background system, the other is designed by using μC/OS-II as administrator. All the application programs were adopted a software model based on finite state machine. A systematic testing process was introduced in details, followed by some testing examples and the testing results. Finally, the functional reliability of the system was evaluated and analyzed.A new model system of DVR was designed and this system successfully realized the functions of remote video recording, multiple methods of alarming record, multiple methods of indexing of record, history playback etc.