There are many kinds of video interface in common life, from the RF to VGA then HDMI, some can only transmit analog signals, some can transmit digital signals, some transmit video and audio signal in one line, and some transmit video and audio signals separately. The following is some introduction about it.
1, RFThe antenna and analog closed-circuit connect TV is used radio frequency (RF) interface. As the most common video connection, which can simultaneously transmit analog video and audio signals. RF interface transmit the mixed-encoded signals of video and audio, the circuit on display device output picture by a series of mixed-signal separation coding, decoding. Due to the need for video, audio, hybrid coding, the signal will be interfere with each other, so it's quality output quality is the worst of all interfaces. Cable and satellite TV receiving equipment is also commonly used RF connections, but in this case, they transmit the digital signal.
2, Composite Video Unlike the RF interface which contain the audio signal, composite video (Composite) usually use yellow RCA (Lotus socket) connectors. "Composite" means analog signals that transmit the brightness and color signal in same channels , but if a TV can not separate these two signals, there will be a shadow. Composite video is the widely used video interface in household appliances as it were.
3, S-VideoS-Video connection using Y / C (luminance / chrominance) separation-output, use the four-wire transmit the signal, the interface is the four-pin interface. two-pin grounded, the other two needles were transmitted light degree and chrominance signals respective. Because the transmission luminance and chrominance signals respectively, S-Video results better than composite video. You also can find S-Video nowadays in many video device like this
USB video adapter. However, S-Video anti-jamming capability is weak, so the length of S-Video cable is better not to over 7 meters.
4, Chromatism Chromatism (Chromatism) are usually labeled as Y/Pb/Pr, use red, green, blue three colors to mark each cable and interfaces. Green cable (Y) transmit luminance signal. Blue and red cables (Pb , And Pr) is the color difference signal transmission. The effect of chromatism is better than S-Video, so a lot of DVD and high-definition playback devices are used the interface. If you use high-quality wire and interfaces, even if A 10-meter-long cable, component cable can transmit good picture also.
5, VGA VGA (Video Graphics Array) has another name known as D-Sub. A VGA interface has total pins of 15, which is divided into three rows, each row of five holes, is the most widely used interface types on the graphics card, the vast majority of graphics card comes with such an interface. It can transmit red, green, and blue analog signals as well as the sync signals (horizontal and vertical signals). Using the VGA connect device, cable length is best not exceeding 10 meters, but also to Note that connector is installed firmly or not, otherwise may cause the image appears a shadow.
6, DVI DVI (Digital Visual Interface) port and VGA are the most common computer interface, and the difference from VGA is that, DVI can transmit digital signals, without carrying out several analog converter, so picture quality is very high. At present, many high-definition television also provides a DVI interface. Note that, DVI interface has a variety of specifications often, DVI-D (Digital) and DVI-I (Intergrated). DVI-D can only transmit digital signals, we can use it to connect video cards and flat-panel TVs. DVI-I can interchange in the DVI-D and VGA.
7, HDMI HDMI (High Definition Multimedia Interface) interface is a recent development interface, it is transmit all-digital signal the same as the DVI. The difference is that HDMI interface can not only transfer High-definition digital video signals, but also can simultaneously transmit high-quality audio signals. Has the same function with the radio interface at the same time, but thanks to all-digital signal transmission, unlike radio frequency interface that poor quality of picture occurs.
8, DisplayPort DisplayPort is a display interface released by Video Electronics Standards Association (VESA). As a successor to DVI interface, DisplayPort will add high-definition audio signals transfer support at the same time in transmitting video signals, while support higher resolution and refresh rate.
According to the design, DisplayPort supports both external display connections, and the built-in display connectivity. VESA want notebook manufacturers not only use DisplayPort to connect independent monitors but also use it directly connected LCD screen and motherboard for easy upgrades on notebook. To this end, DisplayPort interface is also designed to be very small, both to facilitate the use of laptops, but also allows the video card to configure multiple port.
9, IEEE 1394 IEEE 1394, also known as FireWire or iLink, it can transmit digital video and audio and machine control signals with high bandwidth, and very stable. Usually it is mainly used to connect digital video cameras, DVD recorders and other devices. There are two types IEEE 1394 interface: the 6-pin hexagonal interface and a small 4-pin square interface. Hexagonal 6-pin interface can provide power supply to device connected, while the 4-pin Of the square interface can not.
10, BNCBNC (coaxial cable card ring interface) interface is mainly used to connect high-end home theater products, and professional video equipment like some BNC port
CCD camera. BNC cable has five connectors, for receiving red, green, blue, horizontal synchronization and the vertical sync signal. BNC connector allows the video signal to reduce interference between each other can achieve the best signal response effect. In addition, BNC interface connect very tight due to specially designed, do not worry poor contact arising from interface loosening.