CVI, TVI, and AHD are high-definition video transmissions that are progressively scanned on an analog coaxial cable. The chips are placed inside the surveillance security camera. HDCVI High Definition Composite Video Interface, HDCVI is a high-definition composite video interface. It is a high-definition video transmission specification based on coaxial cable. It uses analog modulation technology to transmit progressively scanned HD video. HDCVI technology adopts the self-adaptive technology of independent intellectual property rights to ensure that at least 500 meters of high-quality HD video is transmitted on coaxial cables of 75-3 and above, breaking the transmission limit of the existing transmission technology of high-definition video. In addition, HDCVI technology also has a number of proprietary intellectual property technologies, including synchronous audio signal transmission technology and real-time two-way data communication technology.