In order to realize multi-signal common cable transmission, HDCVI embeds audio signals and bidirectional data communication signals simultaneously in the blanking area. The audio signal is combined in line blanking to increase synchronism with the video signal and supports up to 44.1 kHz sampling rate through automatic compensation techniques. The forward and reverse data channels are combined in frame blanking, and the control signals are transmitted bidirectionally to realize transmission of information between the receiving end and the transmitting end, and support control commands such as camera zoom, pan/tilt rotation, and real-time alarm. The forward transmission data is predictable due to the transmission time and the baud rate of the electrical signal, and the receiving end has a high-performance automatic compensation technology, which can support a higher transmission baud rate. The reverse transmission of data, due to the influence of impedance matching and channel transmission uncertainty, the signal frequency is low and the amount of data transmitted each time is limited, so the supported baud rate is low. Of course, the reverse channel also adopts an automatic compensation technique to perform a certain recovery on the long-distance transmission signal of the electrical signal.