input interface

VGA input interface

VGA interface adopts an asymmetric distribution 15PIN connection method, its working principle: is an simulation in the RAMDAC in the RAMDAC in digital format. Modulated into an analog high frequency signal, then output to plasma imaging, so that the VGA signal is in the input end (in the plasma), it is not necessary to pass the matrix decoding circuit as other video signals. From the previous video imaging principle, it is understood that the video transmission process of the VGA is the shortest, so the VGA interface has many advantages, such as untrue-free-free circuit combination, separation loss, and the like.

HDMI input interface


English full name "high definition multimedia", meaning in Chinese High definition Multimedia interface. The HDMI interface can provide up to 5Gbps data transmission bandwidth, which can transmit uncompressed audio signals and high resolution video signals. At the same time, you can guarantee the highest quality audio and video signal transfer without counting / mode or model / digital conversion prior to signal transmission. The advantage of using HDMI is: only one HDMI line can be transferred at the same time, and it is not like a plurality of wires today. At the same time, due to wireless, digital / mode or model / digital conversion, can achieve higher audio And video transmission quality. For consumers, HDMI technology not only provides clear picture quality, but also due to the use of the audio / video, greatly simplifies the installation of home theater systems.

input interface

DVI input interface

DVI interface is mainly used to connect to a computer graphics card with a digital display output function, display the RGB signal of the computer. DVI (Digital Visual Interface) Digital Display Interface is September 1998, a Digital Display Working Group, which is established in the Intel Developer Forum, and the Digital Display Interface Standard.

DVI digital terminal is better than the standard VGA terminal signal, the digital interface guarantees that the entire content is transmitted in digital format, ensuring that the integrity of the data during the transmission of the monitor (no interference signal introduction), Get a clearest image.

Standard Video Input (RCA) interface

also known as the AV interface, is usually a pair of white audio interfaces and yellow video interfaces, which usually use RCA (commonly known as lotus head ) Connect, only need to connect the standard AV cable with lotion with the respective interface when used. The AV interface realizes the separation transmission of audio and video, which avoids the decrease of image quality due to tone / video mixing interference, but because the AV interface transmission is still a brightness / chroma (Y / C) mixed video The signal still needs to display the device to perform bright / color separation and chrominance decoding to imaging, which will inevitably cause loss of color signals, chromaticity signals and brightness signals will also have a lot of opportunities. Interference thus affects the image quality of the final output. AV also has a certain vital force, but because it itself Y / C mixed this unhabble shortcomings thus cannot be used in some cases of pursuit of visual limits.

s video input

s-video specific English full name called Separate Video, in order to achieve a better video effect, people start to find a more fast and excellent resolution of video transmission The way, this is the S-Video (also known as the two-point video interface), which is currently the day of the day, the meaning of Separateo signal is to transmit the video signal, which is separated by the chroma signal C and the brightness signal Y on the basis of the AV interface. Then, in different channels, it appears and develops in the late 1990s, the standard 4-core (excluding sound) or extended 7-core (including sound). Graphics and video devices with S-Video interface (such as analog video acquisition / editing card TV and quasi-professional monitor TV card / TV box and video projection equipment, etc.) are currently more common, compared with AV interfaces Further, Y / C mixed transmission is therefore no need to perform bright colors separation and decoding, and the respective independent transmission channels are largely avoided to avoid the image distortion generated by the signal crosstalk in the video device, greatly improved the image. The definition, but S-VIDEO still needs to mix the two color difference signals (CR CB) as a way of color signal C, and then decodes CB and CR in the display device, which will still bring a certain signal. Damage and distortion (this distortion is small but can still be found when testing under strict broadcast-level video equipment), and because the mix of Cr CB results in a certain limit of the bandwidth of the chrominance signal, S -Video has already It is more excellent, but the beauty is far away, and the S-Video is not the best, but considering other factors such as market conditions and integrated costs, it is also the most common video interface.

Video color difference input interface

can be seen in some professional video workstations / editing card professional video equipment or high-end tracer, etc., YUV YCBCR Y / BY / BY, etc. The marked interface identifier, although its marking method and joint profile have the same interface color difference port (also known as the component video interface). It usually uses both YPBPR and YCBCR identifiers, the former represents the progressive scan color difference, the latter indicates the interlaced color difference. As can be seen from the above relationship, we only need to know the value of the Y Cr CB (ie, the fourth equation is not necessary), so it is uniformly ignored in the video output and color processing, and only retains the green difference CG Y CR CB, this is the basic definition of color difference output. As the advanced product color difference of S-VIDEO, the chroma signal C transmitted by the S-VIDEO is decomposed into color difference Cr and Cb, which avoids the two-channel color difference mixing and decoding the decoding and separating the process, but also maintains the maximum chroma channel. Bandwidth, only the anti-matrix decoding circuit can be reduced to the RGB three primary color signal, which minimizes the video signal channel between the video source to the display imaging, avoiding the image brought about by a cumbersome transmission process. Distortion, the interface mode of the color difference is the best one in various video output interfaces.

BNC port

is typically used for workstations and coaxial cable connectors, standard professional video equipment input, and output ports. The BNC cable has 5 connectors for receiving red, green, blue, horizontal synchronous and vertical synchronous signals. The BNC connector is different from a special display interface for ordinary 15-pin D-Sub standard connector. Synchronized by R, G, B three primary color signals, and the field synchronization is composed of five separate signal connections. Mainly used to connect the system with high demand for scanning frequencies. The BNC connector can separate the video input signal, which reduces the interference between the signals, and the signal band is large, and the optimal signal response effect can be achieved.

RS232C serial port

RS-232C standard (protocol) is the EIA-RS-232C standard, where EIA (Electronic Industry Association) represents the US Electronic Industry Association, RS (Ecommeded Standard) Represents the recommended standard, 232 is the identification number, C represents the latest revision of RS232 (1969), before this, there is RS232B, RS232A. . It specifies that the cable and machinery, electrical characteristics, signal functions and transmission processes are specified. Common physical standards include EIARS-232-C, EIARS-423A, EIARS-423A, EIARS-485. Here only introduces EIARS-232-C (referred to as 232, RS232) . Computer input output interface is the most common serial interface, and the RS-232C scheduling interface has 25 lines, 4 data lines, 11 control lines, 3 custom-time lines, 7 spare and undefined lines, commonly used only 9, often used in use with 25-Pin D-Sub ports, the maximum transmission rate is 20 kbps, and the cable is up to 15 meters. The RS232C port is used to input a computer signal to control plasma.

Audio input / output interface

can input an audio signal such as a computer, a recorder, etc., and play it with your own speaker. It is also possible to connect the power amplifier, and the external speaker can also be connected.

Another: Input interface is the main parameters of the shared device, refers to the number of interface modes and interfaces, and the switch typically has 4-way 8-way 32 or more input interfaces, using BNC plugs or compounds. Video interface.

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