Audio And Video Capture And Transmission System

As the processing of digital transformation of China’s radio and television system, China’s market urgently need a lot of supporting for HD video equipments. A key issue of video processing equipments for reciprocal communication is the interface of the source and display devices, in which interfaces commonly used in computers are not compatible. Therefore, the audio and video capture and transmission system needs a kind of equipment as middleware to solve the compatible problem of the interface between the devices.In this paper, the FPGA-based audio and video acquisition and transmission system is designed, which supports two analog audio inputs includes left and right channels, three analog video signal input, HD-YPbPr, the SD-YC, SD-CVBS, a digital video signal input and the input and output of compatible HD-SDI and SD-SDI.When HD-YPbPr and analog audio signal input, the analog video signal conducts the A/D conversion and transfer to the FPGA processing by parallel data, while analog audio signal conducts the A/D conversion transfer to the FPGA processing by the I2S bus format. FPGA conducts SDI encoding for signal, and audio plus embedded HD-SDI signal output. When HD-SDI signal is input, the SDI signal transfers to FPGA after equalization, the FPGA SDI decoding the first signal, the audio de-embedding audio and video signal separation, the video data is sent to the back-end video D/A module output by HD-YPbPr format send audio data to the audio D/A module, left and right channel outputs to form the stereo. Processing SD signals and deal with HD signal with the same way, except video data bits wide.In addition, in order to meet the requirements of long distance transmission, the system also supports SDI signal ring into and ring out, which utilizes the SDI signal equalization module to reduce the distortion of the signal transmission process, and the SDI signal driver module is used to strengthen the signal energy over an extended range.This system solved the device interface compatibility problems caused by the diversity of audio and video equipment. The experimental results show that the solution of this article can achieve good results.