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The action of video matrix and technical design point are analytic
From;    Author:Stand originally

1.The action of video matrix

In contemporary multimedia assembly room, differ to satisfy the demand that demonstrates a circumstance, the cause of phonic video signal that can have a variety of differring normally and indication terminal, although sources of these phonic video signal are mixed,indication terminal also may have compound video at the same time (Composite-Video) , super video (S-Video) , heft video (Component-Video) even digital video (DVI, SDI) interface, but inspect the matrix of is used generally compound still video in resembling the conference in multimedia at present, main reason is in as follows a few respects:

* compound video has good stability, compatibility and versatility, transmission bandwidth is small, transmission distance is long. But chroma and brightness share 4.2MHz (NTSC) or 5.0~5.5MHz (PAL) frequency bandwidth, mutual between have string of bigger trouble, not tall to the requirement standard of equipment and transmission line cable, signal source is rich, bury wire cable beforehand investment is inferior.

* super video (S-Video) although reducing brightness loss, brightness / chroma strings together faze respect apparent excel is compound video, but to current and common liquid crystal projector, DLP projector and the distinction with very clear short of, and double burying wire cable to invest beforehand is compound video, transmit in project Sunday run so did not get general use.

* heft video is already apparent on the level of signal format prep above is compound video or super video, but be in at present assembly room majority is to be computer to show (VGA or RGBHV signal format) service, very tall to the requirement of equipment and transmission line cable (depend on expectant design level and investment budget) , bury wire cable beforehand investment is very high.

* similar Y, r-Y, b-Y, Y, cr, the heft video signal of Cb basically applies in wide cable industry at present, and can transfer to the digital signal format of SDI or HD-SDI gradually, because signal source and capital are estimated,restrict, assembly room is used not much. DVI signal is restricted as a result of what transmit a distance effectively (5 meters or so) , did not get applied extensively at present.

Appraise of the place on put together, video matrix did not make clear customarily sound particularly to acquiesce is compound video format. The main equipment that exports with compound video format has: Camera, objective exhibits stage, cable television to inspect machine of smooth like machine of the conference, video tape recording, DVD dish demodulator, remotely to wait, phonic video matrix is in systematic intermediary at video source and show or answer with terminal between, be in charge of source of will different phonic video signal undertaking centralized adjusting control by the apiration of the user.

According to passageway of input, output different, common video matrix has 8 commonly × 2, 8 × 4, 8 × 8, 16 × 4, 16 × 8, 16 × 16, 32 × 8, 32 × 16, 32 × 32, 64 × 16, 64 × 32, 64 × 64. Groovy understanding is how many what input a passageway by the digital delegate before date, how many what output a passageway by the digital delegate at the back of date. No matter the input of matrix outputs a passageway how many, their control method is roughly same: Before control of control of face plate key-press, detached type clavier, tripartite is controlled (RS-232/422/485) , inchoate a few homebred matrix are sucked through relay combine control, this kind of technology has fallen into disuse at present.
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