How We Can Choose Display Interface for Video Surveillance


Video interfaces hook up the monitor to the Picture decoding device. Concerns over image quality and online video protection has led to significant changes in screen interface technology gradually. Actually though the VGA program is still found in Computer systems, the future is moving to digital interfaces. Several methods including analog plug, hybrid digital plus analog interfaces and several digital interfaces have been developed so far. However, there is some overlap in the features of screen interfaces. We study several practical analog and digital video interfaces. pair

Analog screen interfaces


S-video, ranking for Separate Video, transfers video signals over a cable by dividing into two separate signals: one for color and another for brightness. Due to this separation, sharper and higher quality images than composite video can be performed. S-video does not carry audio, so it commonly run with red and white RCA music cables. 

Component video

This kind of video interface is superior over both composite and S-video. Because its 3 cables better preserve the various portions of the online video signal including brightness and color, resulting in increased picture quality. Component online video uses three RCA contacts, Red, Blue and Putting surface to deliver video alerts. It carries visual data only, and therefore music cabling are still required. Therefore, it is usually combined with stereo (red and white) RCA music contacts.


VGA or Online video Graphics Array is the most popular video interconnection between computers and screens. It can be used on computer video cards, projectors and place top boxes. A standard VGA connection has 12-15 pins and supports screen resolution of 640*480 -pixels, while increased version SVGA is allowed for quality of 1024*768. It is worth mentioning that the maximum resolution is limited by the connector band width and cable quality and length.

In the VIDEO GRAPHICS ARRAY connector, due to small little pins into a tiny connector, building small concentrique cables is hard.

Digital display interfaces


Digital Video Interface (DVI) has been designed as a replacement for VGA (analog interface). However, occasionally DVI still supports analog exhibits. In fact, DVI is the only standard which can hold both analog and digital signals on one interface. In case the screen is analog, the DVI connection will convert the digital signal for an analog transmission, otherwise no conversion will be necessary. It is worth mentioning that, the analog video bandwidth of DVI is higher than VGA, thus higher quality can be supported in contrast to VGA. Therefore, it can be applied by high res displays such as UXGA and HDTV.

DVI cables or ports with fewer pins are suitable for lower resolution devices. In order to support maximum resolution, the DVI slot should contain all the pins. Since DVI will not support High-bandwidth Digital Content Protection (HDCP) security by default, by using hardware which only includes DVI ports, the online video protection is not assured. This is the biggest drawback of DVI. As HDCP protects video from against the law copying, this feature is very critical for video surveillance systems.

DVI has several variants: DVI-D (digital only), DVI-A (analog only) and integrated DVI-I which carries both digital and analog video. DVI connections are popular on computer video cards, screens and projectors.


Hi-definition Multimedia Interface (HDMI) transports uncompressed digital HD online video and music data in a single cable, while other connections require independent cables for music and video. For instance, a component cable connection uses three cables for online video and two for audio tracks, resulting in five wires totally. While using HD, the uncompressed music and video information can be transmitted using one cable television, thus cable clutter is eliminated greatly.

Since HIGH DEFINITION is a digital interconnection, it much more robust to interference and noise problem compared to analog contacts. Since most processes are the digital such as DVD players, Blue-ray players and game consoles, so by using HDMI for people consumers the analog to digital conversion will be eliminated. So, it brings about better quality picture and sound compared to other connections. Also HDMI helps HDCP, which means that it is practical for video monitoring systems. HDMI connection is the most popular screen interface, found on every TV, AV receiver, Blue-ray disk player, DVR, laptop computers and cameras, because by using HDMI, there is no need to buy separate audio tracks and online video cables. Therefore, fewer wires and connections are used.


DisplayPort as a standard port to hook up PCs, laptops, and other computers to video screens has been called ultimate digital connection. It is just a high definition AV connection which transmits music and online video data over an one cable with a securing connector. DisplayPort is a simple but high band width interface which provides true digital images and clear sounds. It can even supply power.

One of the features of DisplayPort is that it works with older technology, as by using simple adapters, it is compatible with VIDEO GRAPHICS ARRAY, DVI even HDMI. DisplayPort permits high display performance, robustness, versatility, highest amount of system integration, and great interoperability among various device types. DisplayPort was formerly developed as the next generation laptop or computer display user interface and is available nowadays on a variety of tablets, notebook computers, desktop computers and watches. It is included on all newer Macs and many Dell, HP, and Lenovo computers and is also available on online video graphics cards. DisplayPort can be used for consumer electronics although not common.