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Terminal of conference of high-definition clear video applies interface to look
From;    Author:Stand originally

Two-way video communicates the real time that video communication faces an user as a kind interactively means, still should pass video conference terminal unit finally to transmit the video signal that come over reductive show equipment to what face an user (liquid crystal TV / plasma TV / the back casts TV / the indication equipment such as big screen projector) over, so the choice of video interface, especially the choice of the interface of the field of communication of high-definition clear video that at present we develop especially important, this process should include the option of high-definition camera and interface of video terminal join, terminal of high-definition clear video and tall clarity show the choice of the join interface of equipment.

Conference of high-definition clear video regards a kind of video application as mode, should get used to video of existing digital tall clarity adequately to compress; Transmission communication and interface are normative. At present high-definition clear shows join communication interface regulations basically has the following kinds external: DVI (digital video interface) ; HDMI (interface of high-definition clear multimedia) : Standard terminal; IEEE 1394 terminal: Or " live wire " abbreviation. Still a kind of wide report applies more extensive HD-SDI interface, here nonfeasance basically discusses content.

DVI interface: DVI interface standard was 1999, output a working group by digital video (Digital Display Working Group) a standard that rolls out, main member includes the manufacturer such as HP, IBM, Intel, NEC. Current, use DVI interface consume kind of product to spread all over high clear indication equipment; Flat TV; Show a variety of equipment such as card. The original intent that its design, it is to realize individual PC and liquid crystal to show the digitlization between equipment joins, realize the digitlization of the communication between equipment thereby, be in at present inspect dish broadcast equipment (DVD) showing with flat is to use the field with this the most commonly used technology between equipment. At present in the computer of high-end individual PC advocate board great majority already all configured DVI signal to output interface. Can see DVI interface gets applied extensively gradually from this.

DVI interface is technology of interface of RGB of type of word of a kind of 24 digit, in sheet in DVI join passageway, 3 pairs of low voltage need minute of signal access, use respectively undertake red, green, La San is planted of chroma heft and synchronous signal transmit. Besides, still have channel of the 4th pair of signal. With the clock signal that will convey to resemble element each. Each length is data of 8 digital RGB heft signal is in order to string together linage shed means to undertake conveying. Highest transmission rate can reach every second 1.65Gbps. Accordingly, odd the oldest transmission rate of a DVI join passageway can achieve 4.95Gbit/s. Such transmission speed is very fast, can satisfy very big video data to transmit. It is under this one bandwidth, odd a DVI join passageway is OK fall without the circumstance that compress in data, the deferent task of the signal of high-definition clear video of all formats that place of easy to do ATSC of the United States that finish defines, and, can amount to 1600 × to the indication image of high quality 1200 like number (UXGA) , still can satisfy 1080p / even 60 (namely 1920 × 1080 line by line, refresh rate is 60 hertz) the requirement that image transmits pair of bandwidth. At the same time also the 720P that huge satisfied place of conference of video of high-definition henceforth clear to ask (1280 × 720 line by line) the transmission requirement of signal. 1080p / 60 had been at present high-definition clear video is compressed; The highest format of communication format. If use interface of double passageway DVI, its are the biggest transmission rate can achieve 9.9Gbps (usable bandwidth is 7.92Gbps) , the 2048 × that indication image can achieve refresh rate to be 60 hertz 1536 resemble number (QXGA) picture. Can say henceforth the metropolis in quite long time satisfies us to be opposite the pursuit of high-definition clear image. Meanwhile, DVI standard allows to transmit synchronous signal and digital video signal not only, still can transmit imitate RGB signal. But at the same time problem of its wire cable length restricted its application in a few domains really, although can be passed outside receive signal to magnify equipment can solve a problem, but signal still passed additional link.
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