CDs & DVDs in Ethiopia

The portal functions with the financial support of the Ministry of Digital Development, Communications and Mass Media. The laser head of the reproducing device moves along the rotating disc, like a gramophone needle, reading the recorded information. The history of laser discs begins in the 80s of the last century, when the Dutch company Philips announced a revolution in the field of sound reproduction made by its engineers. They created the first laser discs and turntables. The Dutch really had something to be proud of. Sound quality, durability of sound carriers, their compactness have increased by orders of magnitude! The modest size compared to the giant gramophone records, first of all, became the reason that the new name very soon transformed into a more familiar one today: CD, CD. Let us recall what a compact disk is, since the basic technology has not fundamentally changed with the advent of the next generations of laser media for audio, video and computer information. So, a CD consists of three layers: the main one, made of plast CDs & DVDs in Ethiopia ic (polycarbonate); reflective - from aluminum, silver and even gold and protective - from transparent polyacrylate varnish. The main layer carries useful information encoded in microscopic depressions burned into it by a laser - pits (from the English pit - pit). The alternation of pits and flat areas, located, like in a gramophone record, in a spiral from the periphery to the center, this is a digital recording of extremely high density. The first CDs were recorded like gramophone records: once and for all. They are called CD-R (Recordable). However, very soon there were discs for multiple rewriting - CD-RW (ReWritable). The manufacturing technology of the latter is somewhat different. Information is recorded not on a layer of plastic, but on a film made of a special metal alloy, which changes its properties under the influence of laser heating and forms an alternation of dark and light areas. Such discs can be rewritten up to 1000 times without loss of recording quality! CDs carried 700 megabytes of information, and against the background of the memory volumes of the then personal computers, it looked amazing. It is clear that for the digital recording method there is no difference in what exactly to record - a computer program, music or video. The five-inch disc contained puzzling computer games, libraries of 10 thousand titles! But it was not possible to record a movie on a CD - there is not enough space. However, let's be precise: films on CD were still recorded using a special program that provides a more dense compression of information, the so-called MPEG-2, then MPEG-3 and MPEG-4 formats. But the quality of the recordings was far from perfect, and they could only be viewed on a computer screen. It took almost ten years and several billion dollars to move to the second stage of the revolution, and not only the Dutch were involved in it. In 1995, ten leaders of the computer industry united efforts to create the next generation of CDs: Hitachi, Matsushiba, Mitsubishi, Toshiba, Sony, Thomson, GBC, Philips, Time Warner and Pioneer. The result was the emergence of a new disc - DVD. Interestingly, at first this abbreviation stands for Digital Video Disc, that is, digital video disc. A year passed until the creators realized the possibilities of their creation, clearly not limited to the sphere of the film industry. By that time, the abbreviation DVD had become common, but now it was decrypted differently: Digital Versative Disc - a digital multifunctional disc. With full technological similarity with its predecessor, its main difference from CD was the increased information recording density by an order of magnitude. The pit sizes have decreased from 0.83 to 0.4 microns, and the width of the spiral path has decreased from 1.6 to 0.74 microns. Thus, on one side of the disk, there was already 4.7 gigabytes of information. But that is not all. They learned how to make DVDs: a) double-sided, b) double-layer, c) double-sided and double-layer at the same time, increasing the total memory capacity of one disc to 17 gigabytes. This was quite enough to record not only the "picture" of the film of the highest quality, but also soundtrack on several soundtracks to create a stereo effect or sound simultaneously in eight different languages, demonstration of subtitles in 32 languages, any of which the user selects by simply pressing the keys on the remote control video player. In fact, the pr https://jiji.com.et/cds-and-dvds