What is DVD what they are and what are protected by?
Today DVD is so popular that everyone without effort will tell what is it as looks, how much is. Though … you know, no! I do not argue, perhaps, many also have an idea of what is it, but in such small quantity that they need to learn more. Well, I invite you to walk on the disk DVD for its detailed studying.
That, where, when?
there was DVD not so long ago, namely in 1995 - m to year in the spring when on the world extremely pleasant news expatiated on development of DVD. Who authors of this most wonderful invention? Authors are the ten large world companies: SONY, TOSHIBA, HITACHI, JVC, PHILIPS, THOMSON, PIONEER, MITSUBISHI, TIME WARNER and MATSUSHITA. Oho - go, how many the large companies! And why all of them worked on one format? To that there is a reasonable explanation: they did not want to launch war of standards and created of DVD Consortium to which duties they belonged advance of a product in the market, the coordinated development of new specifications and licensing of the enterprises which are writing down information on DVD. Well, and in 1997 - the m was created to year by of DVD - a forum which actually and replaced DVD Consortium.
What means DVD?
After a novelty exit to the public to it were named of Digital Video Disk (Digital Video the Disk). Just because the first DVD intended for display of video and had to replace the videotapes (VHS) loved by all of us. But clever brains considered that the format needs to be finished, made it not only multimedia, but also available to computers. In that case the first name DVD did not approach any more, and therefore its new value - appeared of Digital Versatile Disk (the Digital Universal Disk).
in What DVD differs from CD?
Oh... differs in much! For example, the fact that on DVD (from 4,7 to 17 GB) more information, than is located on CD (750 - 800 MB) . Thanks to the fact that density (0,74 microns, and on CD of 1,6 microns) is one DVD more than placement of data and still there is a dvukhsloynost (one information, other protective - at the same time reading and record is carried out by change of focusing of a beam). To everything, DVD protection against piracy copying will have plus more abruptly. Well, “ DVD more abruptly than any CDs “.
That such special in protection of DVD?
Yes anything special, so-so, usual disk. I joke! Actually DVD has difficult system of protection.
1. From scratches and external damages. Has two layers, one of which represents a thin film with transparency in 40%, and carries out protective function.
2. From piracy copies. Each DVD and each DVD - the drive has the zone and cannot accept DVD from other zone. It is made in order to avoid premieres of movies at the same time and in different places.
All such zones eight: 1 zone - Canada and the USA; The 2nd zone - Japan, Europe, South Africa, the Middle East; The 3rd zone - Hugo - the East of Asia, East Asia; The 4th zone - Australia, New Zealand, the Pacific islands, the Caribbean islands, the South and Central America; The 5th zone - the territory of the former USSR, the Indian peninsula, the main part of Africa; The 6th zone - China; The 7th zone - the reserved zone; The 8th zone - exterritorial: planes, liners, steamships...
Exists and one more protective system is of CSS (Content Scrambling System) . All information on a disk is coded, and therefore it is almost impossible to record it with the
And the last system of protection is of APS (Analogue Protection System) . When viewing video hindrances are created and if you rewrite this movie, then there will be such hindrances - simply “ pleasure never-ending “.
of DVD - 5 - a unilateral single-layer disk with a capacity of 4,7 GB (cheaper is also more popular).
of DVD - 10 - a bilateral single-layer disk with a capacity of 9,4 GB (cheaper is also more popular).
of DVD - 9 - a unilateral two-layer disk with a capacity of 8,5 GB (is unpopular).
of DVD - 14 - a bilateral disk: on one party - one layer, on another - two; capacity - 13,24 GB (expensively).
of DVD - 18 - a bilateral two-layer disk with a capacity of 17 GB (expensively, it is unpopular).
I hope, you liked our walk! Though tiresome, but informative.
To new meetings!