Video Monitoring, Collection, Display Subsystem And Rate Control Research And Realization

It is most extensively used Lines of Communication to Public Switched Telephone Network (PSTN), hence the video surveillance system based on PSTN possesses widespread application prospects. This thesis discusses detailed the design and realization of capture subsystem and display subsystem which are primary modules of the video surveillance system, and study in-depth one of the system critical technology- rate control of the video encoder.It possesses inferior universality for most video capture subsystems that are accomplished through the non-standard interface. The thesis study the standard interface: Video For Windows and DirectShow, and put forward a video capture subsystem based on DirectShow, the subsystem independent of specific hardware has preferable universality. In addition the thesis discuss clearly other problems of the subsystem.Owing to differ of display device, display functions utilize different technology to display images. Moreover, display modes are switched dynamically at system running. In order to solve these questions the thesis presents a multi-display modes dynamic adaptation algorithm. Additionally the thesis put forward a solution of multi-channel video decoding and display.It is the key problem of the system above PSTN that how to transmit low-delay and high-grade video image. For the problem solving, the thesis study rate control of the video encoder. The thesis discusses the rate control arithmetic of MPEG-4 based on quadratic rate distortion model, and then presents a rate control arithmetic of I frame and improves the adjust policy of quantisation param. The experimental results show that the refinement arithmetic reduces greatly the delay of encoder buffer, at the same time improves clearly the quality of reconstruct image.