Sunday, March 13, 2011

Why We Need An HDMI Cable In This Day And Age

By Areelitaha Joahlanski


High Definition Multimedia Interface cables (HDMI cable) is able to use a digital signal to send a progressive scan. What exactly is that anyway?

An analogue signal is when an electrical current is varied as it is sent up a wire. Information can be sent in this way. Analogue signals, unlike digital, really are high resolution. Digital is only as high resolution as processing power allows, but analogue is nothing more than a stream of electrons being conducted along a surface such as silver. It can be zoomed in to very small degrees. This is only practical to a point, however, because the components necessary would have to be finer and finer.

That's why digital is better. It can be very fine, very easily. It's nothing more than a stream of data. The more data, the finer the signal. The faster the processing chip, the more data. It's much easier to create a fast processing chip, just narrow the laser that etches it. Of course, you only make the signal as fine as you need it, which means it will break down very fast if you try to zoom in.

The ubiquitous "ones and zeros" that people are always talking about make up digital signals, but what is that really? "Ones" tell circuits on a processor to open, and "zeros" tell it to close. Since a computer is really nothing more than an input-output device, those opening and closing circuits are just making more ones and zeros for another piece of the hardware.

Interlaced scanning is when the picture on the screen is made up of many half-frames per second, flashing in sequence. There are between twenty-four and thirty frames in each second on screen, depending on which part of the world you're in. Each frame is really every other line of the picture, with the following frame being the missing set of lines from the second frame. At no time is the whole frame ever on screen, but it's so quick that the human eye sees them as a whole picture. Only half the information needs to be sent up the wire each frame.

Progressive scans are whole pictures being sent, each frame. The old monitors, cathode ray tubes, worked by firing a stream of electrons at the back of the screen. It was done in the same pattern as the incoming frame, over and over and over again. But HD monitors receive the information row by row, making a whole picture each time.

Thus, even though analogue may be able to be finely divided far beyond digital, it's not practical to create it so fine. An HDMI cable can broadcast the digital data that can be created finer.




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