| With growing scale of monitoring systems and higher unmanned requirements, it is a good solution to reduce the workload of operation and maintenance personnel and improve the efficiency of the substation by using video quality diagnostic system. Due to lack of unified standards and effective methods on the practical test, how to measure its effect and accuracy has become the primary problem before large-scale application. In order to detect the video quality diagnostic system used by State Grid Sichuan Electric Power Company, the detection technology of video quality diagnostic system is studied by programming and taking the advantage of system’s characters.Through the investigation about video quality diagnostic system, two features have been summed. The first feature is that the worse video quality gets the higher score. The second one is that the diagnostic system supports H.264 video encoding format only. The former character shows that the fault video files of different degrees should be gotten before testing. The latter one shows that the fault files should be recoded in order to be detected by the system.A program for video processing, eight video fault simulation algorithms and a video codec program have been done. A program for video processing which includes the operations of video reading, processing and writing, is completed by using Open Source Computer Vision Library(Open CV). By changing the key parameters in video fault simulation algorithm can control the fault degree for each type of video failure. In that way, a bundle of different degrees of fault video files are available for each type of fault by combing with the previous video processing program. After that, a bundle of standard H.264 video format can be gotten with the help of FFmpeg video codec program and the H.264 format video can be transcoded into the format the diagnostic system supported with the help of the existing video conversion tool.Record the diagnostic scores obtained by different degrees and different types of fault video by taking the advantage of the diagnostic system’s feature. A qualitative evaluation is made by the relationship between the diagnostic scores and the basic parameters which control the fault degree.In summary, the test technology of video quality diagnostic system is studied and a practicable detection scheme is proposed to provide a reference for the formal application of the diagnostic system in this paper. |
