Compared with VGA, HDMI, DP and other interfaces, DVI interface is the most important LED display interface at present.

Digital display working group

DVI (Digital Visual Interface) interface, that is, digital video interface. DVI can transmit digital signals without digital-to-analog conversion, so the picture quality is very high. At present, there are two common DVI interfaces, namely DVI-Digital(DVI-D) and DVI-Integrated(DVI-I). DVI-D only supports digital signals, while DVI-I not only supports digital signals, but also supports analog signals, which means that DVI-I is more compatible.

The biggest advantage of DVI interface transmission is fast speed and clear picture. DVI transmission is a digital signal, which does not need to go through the complex conversion process from digital to analog and then to digital, thus greatly saving time and effectively eliminating the smear phenomenon while speeding up the speed. Compared with VGA, DVI makes the picture more delicate at high resolution and less susceptible to signal interference.

DVI-I socket is compatible with digital and analog connectors, so DVI-I socket has 24 digital pins +5 analog pins (that is, four pinholes and a cross next to it). DVI-D socket is a pure digital interface, so DVI-D socket has only 24 digital pin sockets (there are no analog four pin holes and a cross). Therefore, DVI-I sockets can be plugged into DVI-I and DVI-D connectors, while DVI-D sockets can only be connected with DVI-D pure digital lines.

It is worth noting that DVI interface can only transmit image signals, and the support for digital audio signals is completely ignored.

2.VGA interface

VGA (video graphics array), video graphics array and VGA interface are special interfaces for computers to output data according to VGA standard. * * * There are 15 pins, which are divided into 3 rows with 5 holes in each row. It is the most widely used interface type on graphics cards, and most graphics cards have such interfaces. It transmits red, green and blue analog signals and synchronous signals (horizontal and vertical signals). ?

VGA interface

Its working principle is: the image (frame) signal stored in digital format in video memory is analog modulated into analog high-frequency signal in RAMDAC, and then output to display equipment for imaging.

Many people think that only HDMI interface can transmit high-definition signals. Sometimes this is a misunderstanding, because VGA connection can also display the image of 1080P, and even the resolution can be higher.

3.HDMI interface

HDMI is a new generation of multimedia interface standard, the full name is high-definition multimedia interface, which means high-definition multimedia interface in Chinese. Like DVI, it transmits all-digital signals. The difference is that HDMI can not only meet the resolution of 1080P, but also support the digital audio format, that is to say, one line can realize the synchronous transmission of video and audio. It can be said that HDMI interface is an improvement of DVI interface and is fully compatible with DVI interface standard.

HDMI interface

Compared with DVI and VGA, HDMI interface is smaller in size, but it is easier to loosen because of its smaller port and no reinforcement device, so it is not as widely used in LED splicing/processor as DVI and VGA.

4.SDI interface

SDI interface is the abbreviation of "serial digital interface". Coaxial cable is adopted, and BNC interface is adopted as the cable standard. In other words, in the process of transforming the existing traditional analog frame system into a high-definition monitoring system, we only need to replace the front-end and back-end parts without rewiring, which will save huge time and labor costs for the project. Therefore, in recent years, the application in LED splicing/processor has gradually increased.

SDI interface

5. Display port interface

DisplayPort is a display interface published by video electronics standards association (VESA). The abbreviation of DP, as the successor of DVI interface, DisplayPort will support the transmission of high-definition audio signals while transmitting video signals, and also support higher resolution and refresh rate. When high-definition video is about to be popularized, it is untenable without a high-bandwidth display interface. At the beginning of DP, the bandwidth it can provide is as high as 10.8Gb/s, and even the bandwidth provided by HDMI 1.3 is slightly lower than that provided by DP1.0; ; In addition, DP can realize more functions than audio and video signals on one cable. Undoubtedly, it is to achieve maximum integration and control of peripheral devices.

Display port

However, due to various restrictions, DP interface is still not the mainstream interface of LED splicing/processor, but its superior transmission quality, high scalability and more reliable content protection technology are bound to be the new trend.