Research And Development Of Seamless Switching Hybrid Video Matrix System

Under the general trend of rapid development of electronic technology,there will be multiple video sources and multiple displays in the same place.In order to facilitate the management of these video sources and displays,video matrix switcher is created.In addition,the current epidemic is spreading all over the world,multi-source video conferencing applications are increasing,and the demand for video matrix is increasing sharply.This paper studies the video matrix,and designs a video matrix system with multi-channel input and multi-channel output that can be controlled by PC and the mobile terminal according to the requirements of engineering applications.Firstly,according to the actual engineering application of the video matrix,the design requirements of the video matrix are analyzed,the appropriate integrated chips are selected,the data manuals of the chips are collected,the system development environment is set up,and the overall scheme of the video matrix system is given.Secondly,this paper studies the basic composition and related technologies of the video matrix system.Using STM32 and the switching chip LT8644,a high-definition video matrix with 32 differential input channels and 32 differential output channels is designed and implemented.Using Altium Designer to design the system circuit schematic diagram and PCB layout,including video interface module,high-speed switching module,serial network communication module,liquid crystal display module,etc.The embedded development software Keil 5 and STM32 Cube MX are used to design the lower computer software,including control switching module,network port driver module,etc.The upper computer software of PC adopts the Delphi platform,and the human-computer interaction interface and communication system software are developed.The upper computer software on the mobile terminal is developed using the Android Studio platform,the communication protocol is based on the standard TCP/IP protocol,and the Socket is used to complete the communication.Then,based on the HDMI video matrix,the video codec is studied,and a hybrid video matrix system is designed.The hybrid video matrix system decodes different types of input signals and turns them into a unified differential signal and sends them to the switching chip.The output differential signal is processed by FPGA and DDR.After the data conversion,it is sent to the encoding chip.The encoding chip encodes and outputs the video data.In order to achieve seamless switching,two DDRs are designed on the input side,one to store the video data before switching,and the other to store the video data to be switched.Finally,after testing and confirming that the voltage of the video matrix system is normal,use the human-computer interaction software of the upper computer to control the lower computer for functional testing.The system's serial communication,client software network port communication,APP and lower computer communication,multi-channel switching control and other functions are tested,and the test results have good performance.After trial operation,the developed video matrix prototype has high stability and can meet actual engineering needs.