In the audio and video processing industry, VGA, DVI, HDMI are our commonly used interface methods, so what is the difference between them? Below Sunny will take you to understand the differences and characteristics of VGA, DVI, and HDMI.

These three are not equivalent, HDMI and VGA are both signal transmission methods, and HDMI refers to a video and frequency resolution. HDMI supports high definition, and VGA also supports it. HDMI currently supports a high-definition format of 1920*1080P, VGA supports various resolutions from 640*480 up to 2560*1600, but VGA-level is easily interfered by other signals, so the high-definition resolution seems a bit virtual, in order to avoid The screen is disturbed, and the VGA interface can be used if the resolution is below 1920*1080P.

Misunderstanding 2: HDMI bandwidth is high, VGA bandwidth is low, so HDMI is better than VGA

The bandwidth of HDMI is the bandwidth of digital signals, and VGA is the bandwidth of analog signals. These are the transmission methods of two different technologies. If you want to compare, you can compare with the same resolution. For example, high-definition, HDMI requires 2.2GHz bandwidth, while VGA only requires 172MHz bandwidth. However, high bandwidth does not mean that HDMI transmits more video and frequency signals. This is just because of the difference in transmission technology.

Misunderstanding 3: HDMI signal does not require digital-to-analog conversion, no signal loss; VGA signal requires digital-to-analog conversion, signal loss is large

Although HDMI does not require digital-to-analog conversion, it still needs to undergo digital-to-digital conversion. No matter what conversion process it is, and what it converts into, it is after all a description of analog electricity and signals. Their relationship is as follows:

The signal described by the digital signal is composed of points, which are discontinuous in the change of the signal, while the change of the analog signal is a continuous curve. When a digital signal is converted to an analog signal, the points (sampling points of the digital signal) are directly output, and the parts that are not described will be automatically generated by the conversion program (similar to 3D anti-aliasing technology) to form a continuous Analog signal waveform. When an analog signal is converted to a digital signal, the continuous analog signal is converted into a digital signal describing each point, and the signal becomes incomplete. From the perspective of this process, the conversion of digital signals to analog signals is enhanced rather than loss, and only when analog signals are converted to digital signals can there be losses.

In the VGA transmission process, the signal loss of VGA to LVDS driving the LCD panel can be ignored, because when the front and back digital sampling rates are the same, these lost signals are originally (when converting digital signals to analog signals). The program automatically The part to be filled is not the loss of the original signal of the digital signal source.

2. Features of VGA, DVI, HDMI

VGA (Video Graphics Array) also has a name called D-Sub. It is an analog signal and can only transmit video-frequency signals. The VGA interface has a total of 15 pins and is divided into 3 rows with 5 holes in each row. It is a widely used interface type on graphics cards. Most graphics cards have this type of interface. It transmits red, green, and blue analog signals and synchronization signals (horizontal and vertical signals). Use VGA to connect the device, the cable length is recommended not to exceed 10 meters, and pay attention to whether the connector is installed firmly, otherwise it may cause ghosting in the image.

BeingHDMI VGA matrix

 Features:

1. VGA supports the simultaneous display of 16 colors or 256 grayscales at a higher resolution of 640×480, and 256 colors at the same time at a resolution of 320×240. Even if the resolution is low, the image is still vivid and vivid.

2, Can't communicate audio.

3. Generally, it is about 30 meters without amplifier and converter, and it can reach 150 meters with amplifier and converter.

DVI

DVI is a digital video and frequency interface, which is a technology for high-speed transmission of digital signals without digital-to-analog conversion. There are many specifications for the DVI interface, the common ones are DVI-A, DVI-D and DVI-I. DVI video and frequency transmission avoids the digital-to-analog conversion process at the sending end (usually a graphics card) and the analog-to-digital conversion process at the receiving end (usually an LCD display) during the transmission of analog video and frequency signals, and also avoids the process of analog signal transmission. The problem of noise interference, so the image is not lost.

BeingHDMI DIV Matrix

Features:

1. The digital signal avoids the analog/digital conversion process, the signal is not attenuated, and the color is purer and lifelike.

2, can transmit video and frequency signals.

3, support multiple formats, including 1920*1080 all high-definition formats.

4. The effective transmission distance is about 5 meters.

HDMI

High Definition Multimedia Inter-face (English: High Definition Multimedia Inter-face, HDMI) is a digital video, frequency/audio interface, technology, is a special digital interface suitable for image transmission, which can transmit audio and video signals at the same time, high The data transmission speed is 5Gbps. At the same time, there is no need to perform digital/analog or analog/digital conversion before signal transmission.

BeingHDMI HDMI Matrix

Features:

1. It can transmit uncompressed audio signals and high-resolution video, audio, and digital signals with high quality.

2, increase the data transmission bandwidth up to 5Gbps.

3. Highly capable of supporting 1080P video.

4. Theoretical 20m, but a good quality line is required, which is generally within 15m on the market.

5. Simultaneous transmission of audio and video, and support for copyright protection, is very popular in the field of consumer electronics.

After reading these, do you have any new understanding of these three video and frequency interfaces? Can you tell the difference between them clearly?