The AV interface is a composite video interface (Audio, Video interface), which is the most common video interface and transmits analog audio and video signals. Almost all TV sets and DVD players have this interface. It is a video interface that separates audio and video. It is generally composed of three independent RCA plugs (also called lotus interface, RCA interface). Among them, the V interface is connected to the mixed video signal and is a yellow socket; the L interface is connected to the left channel sound signal. The white socket; the R socket is connected to the right channel sound signal, which is the red socket.
There are two types of terminals for the AV interface: RCA terminal and BNC terminal. The RCA terminal is the so-called lotus head and lotus seat, and the BNC terminal is the BNC head and BNC seat. RCA terminals can be used in both composite video interface and audio interface. If used in audio interface, it is usually called 3.5 lotus head (seat).
The advantages of the AV interface are simple and easy to use, widely compatible, and low cost. The disadvantage is that the picture quality is poor, it is easy to be disturbed, and it does not support high-definition resolution. The maximum resolution supported by the AV interface is 720x576.
The S-video interface is an independent video terminal (Separate Video), also known as Y/C (or mistakenly called S-VHS or "Super Video (Super Video)"). It is an analog signal that divides video data into two separate signals (luminance and chrominance) for transmission, unlike composite video, where all signals are packaged into a whole for transmission. S-Video supports 480i or 576i resolution.
The S-video interface is a special interface for video signals, which is an upgraded version of the AV interface. It is also an analog signal transmission, but the picture quality is better. Since the synthesis, encoding and synthesis of the image signal Y and the chrominance signal C are omitted, as well as the input switching and matrix decoding in the TV set, the mutual crosstalk between the composite output of the luminance and chrominance signals can be effectively prevented, and the clarity of the image can be improved. . It is mostly used for connecting with cameras.
The S-video interface is not a common interface, it is only used when connecting an external DVD or game console, so ordinary consumers don't need to consider this terminal, and most LCD TVs are equipped with this interface.
The advantage of the S-video interface is that the picture quality is better, clearer than the AV interface, less susceptible to interference, and suitable for connecting devices such as cameras. The disadvantage is that it can only transmit video signals, does not support audio signals, requires an additional audio cable, and does not support high-definition resolution. The maximum resolution supported by the S-video interface is 1024x768.
Chromatic aberration interface
The component video interface is an analog interface that decomposes the video signal into two channels of brightness and color difference signals for transmission, also known as component video interface (Component Video). It consists of three RCA plugs, namely Y, Pb, Pr or Y, Cb, Cr, where Y represents the brightness signal, Pb or Cb represents the difference signal between blue and brightness, and Pr or Cr represents the difference between red and brightness value signal. The maximum resolution supported by the component interface is 1920x1080.
The advantage of the component interface is that the picture quality is better, clearer than the S-video interface, and it can transmit high-definition resolution video signals, which is suitable for connecting DVDs, game consoles and other devices. The disadvantage is that it can only transmit video signals, and does not support audio signals. It needs to be connected with an additional audio cable, and the display device needs to support component input.
VGA interface is the abbreviation of Video Graphics Array (Video Graphics Array), also known as D-sub interface, which is a classic blue interface with 15 pins divided into 3 rows and does not support hot swapping. VGA uses analog signals for transmission. Due to the digital-analog-digital signal conversion process, some loss of image details will inevitably occur.
The advantage of the VGA interface is that it is easy to use, widely compatible, and low in cost. The disadvantage is that the picture quality is poor, it is easy to be interfered, it does not support audio signals, and there is little room for bandwidth improvement. The maximum resolution supported by the VGA interface is 1600x1200.
DVI interface is the abbreviation of Digital Visual Interface (Digital Visual Interface), established in September 1998 on the Intel Forum, does not support hot plugging. Due to the adoption of digital signal transmission, it has better performance than the old-fashioned VGA interface. Nowadays, the latest DVI-D interface already supports 2560x1600, 60Hz/1920x1080, 120Hz.
The advantage of the DVI interface is that the picture quality is better, clearer than the VGA interface, and can transmit high-definition resolution video signals. The disadvantage is that it can only transmit video signals, does not support audio signals, and is limited by its own standards, so there is little room for bandwidth improvement. The maximum resolution supported by the DVI interface is 2560x1600.
Classified according to the number of pins, DVI derives three different types of interface forms: DVI-A, DVI-D and DVI-I. DVI-A is an analog interface (actually the VGA interface standard), DVI-D is a digital interface (true digital signal transmission), DVI-I has digital and analog interfaces (integrated the above-mentioned DVI-A and DVI-D interface Collectively).
It can be seen from the analysis in this article that different video interfaces have their own advantages and limitations, and no interface is perfect. Generally speaking, the interface for digital signal transmission is better than the interface for analog signal transmission, but it also requires higher bandwidth and compatibility. An interface that transmits audio signals and video signals simultaneously is more convenient than an interface that transmits them separately, but also requires more wires and terminals.
Therefore, when choosing a video interface, you need to comprehensively consider various factors according to your own needs and equipment conditions, and choose the most suitable interface for you. For example, if you need to connect a high-definition device, you can choose a DVI or component interface; if you need to connect a camera or game console, you can choose an S-video interface; if you need to connect an old-fashioned device, you can choose an AV interface; if you need to connect a computer monitor, you can choose a VGA interface interface.
Of course, with the development of technology, some new video interfaces are emerging, such as HDMI, DP, etc. They have higher performance and more functions, and they are also worthy of attention and learning. This article is just a brief introduction and comparison of five common video interfaces, and does not involve all the details and technical specifications, hoping to provide some reference and inspiration for readers.