At present, the basic video interface is composite video interface, S-vidio interface; Also common are color difference interface, VGA interface, interface, HDMI interface, SDI interface.

1, composite video interface

Composite Video interface is also called AV interface or video interface, is currently a common video interface, almost all TV, DVD player products have this interface. It is a video interface separated from audio and video, generally composed of three independent RCA plugs (also known as plum interface, RCA interface), in which the V interface is connected to a mixed video signal, which is a yellow jack; L interface connected to the left channel sound signal, white jack; The R port connects to the sound signal of the right channel and is a red port.

2. S-Video interface

The S interface is also a very common interface, and its full name is Separate Video, also known as SUPER VIDEO. S-video connection specification is a specification developed by the Japanese, S refers to "SEPARATE (separate)", it will separate the brightness and chroma output, to avoid the mutual interference of brightness and chroma when the mixed Video signal output. The S interface is actually a five-core interface, which is composed of two visual brightness signals, two video chrominance signals and a common shielding ground wire.

3. YPbPr/YCbCr color difference interface

The color difference interface is based on the S interface, the blue difference (b) and red difference (r) in the chroma (C) signal are sent separately, and its resolution can reach more than 600 lines. It usually uses YPbPr and YCbCr two identification, the former indicates the progressive scan color difference output, the latter indicates the interlaced scan color difference output. Now many TV products rely on color difference input to improve the quality of the input signal, and through the color difference interface, you can input a variety of levels of signals, from the basic 480i to the 480p of the frequency doubled scan, and even 720p, 1080i, etc., are to pass the color difference input to have a way to transmit the signal to the TV.

4. VGA port

The VGA port is also called the D-Sub port. VGA interface is a D-type interface, there are 15 pins on it, divided into three rows, each row of five. VGA interface is widely used in the graphics card interface type, the vast majority of graphics cards have this interface. Mini audio or home theater with a VGA interface can be easily connected to the computer's monitor, using the computer's monitor to display images.

5. DVI interface

The current DVI interface is divided into two types: one is the DVI-D interface, which can only receive digital signals. The interface has only 24 pins in 3 rows and 8 columns, and the one pin in the upper right corner is empty. Not compatible with analog signals. The other is the DVI-I interface, which is compatible with both analog and digital signals. Compatible with analog fortunately does not mean that the analog signal interface D-Sub interface can be connected to the DVI-I interface, but must be used through a conversion connector, generally using this interface graphics cards will have the relevant conversion connector.

6. SDI interface

The SDI interface is a "digital component serial interface". Serial interface is the interface that sends each bit of data and corresponding data sequentially through a single channel. Because of the high data rate of serial digital signals, they must be processed before transmission. Earlier block codes were replaced with non-return-to-zero inversions of scrambled codes (NRZI), the standards SMPTE-259M and EBU-Tech-3267, which included digital composite and digital component signals including digital audio. Before transmission, the original data stream is scrambled and converted into NRZI code to ensure reliable recovery of the original data at the receiving end. In this way, the digital serial interface can be conceptually understood as a baseband signal modulation. The SDI interface can pass 270Mb/s serial digital component signal, and for 16:9 format images, it should be able to transmit 360Mb/s signal.

7, HDMI interface

The full name of HDMI in English is "High Definition Multimedia", which means high definition multimedia interface in Chinese. HDMI interface can provide up to 5Gbps data transmission bandwidth, can transmit uncompressed audio signals and high-resolution video signals. At the same time, there is no need to perform digital/analog or analog/digital conversion before signal transmission, which can ensure high-quality audio and video signal transmission. The advantage of applying HDMI is that only one HDMI cable is needed to transmit audio and video signals at the same time, rather than requiring multiple wires to connect. At the same time, thanks to wireless digital/analog or analog/digital conversion, higher audio and video transmission quality can be achieved. For consumers, HDMI technology not only provides clear picture quality, but also greatly simplifies the installation of home theater systems because audio/video uses the same cable.

8. IEEE1394 interface

IEEE 1394, also known as Firewire or iLink, is capable of transmitting digital video and audio and machine control signals, with high bandwidth, and is very stable. Usually it is mainly used to connect digital cameras, DVD recorders and other devices. There are two types of IEEE 1394 interfaces: 6-pin hexagonal interfaces and 4-pin small quadrangular interfaces. The 6-pin hexagonal interface provides power to the connected device, while the 4-pin quadrangle interface does not.

9. BNC interface

BNC interface refers to the coaxial cable interface, BNC interface is used for 75 euro coaxial cable connection, providing receiving (RX), sending (TX) two channels, it is used for the connection of non-balanced signals.