| Types of DVD and history of
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| | that DVD was initially designed for.
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| developmentIt's been a long time since
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| | Compared with VHS tapes DVD-Video is a
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| DVD became common in our everyday life.
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| | giant leap into the future. There are
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| However, most people don't seem to know
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| | heaps of features there that most people
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| what it is exactly. Answers to questions
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| | have no idea about.First of all,
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| like "what sort of arcane symbols are
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| | DVD-Video is interactive - any place on
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| printed on disk boxes", "how come DVD is
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| | the disk is instantly accessible and it
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| different from CD if they look so
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| | is possible to have more than one ending
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| similar", "what kinds of DVDs are there"
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| | for the movie. And parents can limit
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| and many others still remain mystery for
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| | viewing of naughty parts of movies for
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| many users. And instead of making
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| | their children. Apart from that disks can
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| conscious choice they just buy randomly
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| | have additional bonus materials, such as
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| without any knowledge of what exactly
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| | interviews, promotion trailers, slides,
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| they are getting.We will examine DVD in
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| | text info and even videogames. In
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| details, along with its history and
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| | addition to all this DVD-Video is capable
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| different types available on the market.
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| | to have multi angle view option, when
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| DVD-Video will get most attention as it
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| | camera angle can be changed during
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| is the most common type of DVDs.What is
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| | playback. However, this feature mostly
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| DVD? Initially DVD standard was designed
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| | used in porno movies and live concert
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| for video storage only. Thus its acronym
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| | records.Video data on DVD-Video disks is
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| was decrypted as Digital Video Disk.
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| | compressed by using MPEG-2 compression.
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| Later, when DVD started to become popular
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| | This compression algorithm allows
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| for storage of all types of data, another
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| | shrinking video stream approximately ten
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| meaning for DVD acronym was introduced -
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| | times, without loss of picture quality.
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| Digital Versatile Disk, which is still
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| | As a result, each disk is able to hold up
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| used nowadays.Generally, DVD is the next
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| | to 4 hours of video with 720x576
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| generation of CD. First of all, DVD
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| | resolution at 24 frames per second (PAL)
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| differs from CD by its significantly
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| | or 720x480 at 30 frames per second
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| larger capacity. While CD disk can only
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| | (NTSC). The streaming speed is usually
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| contain between 650 and 800 megabytes,
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| | between 3 and 10 MBit per second.Video
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| DVD is able to hold anywhere between 1
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| | can be recorded in different screen
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| and 17 gigabytes, depending on disk type.
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| | ratios. For example, it can have ratio of
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| This storage increase is achieved by
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| | 4:3, which is a standard television
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| reducing laser wavelength. But DVD
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| | ratio, or widescreen - 16:9. Widescreen
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| capacity would never reach more than 4.7
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| | image have two types: Letterbox and
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| gigabytes if it wasn't possible to make
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| | anamorphic. In the first case image is
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| DVD disks double-layered or
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| | simply cropped at the top and at the
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| double-sided.One side of double-layered
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| | bottom to achieve desired format. In
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| disk can contain two layers of data. To
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| | anamorphic mode the image is initially
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| avoid interlapping, outer layer is made
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| | recorded in stretched form and then
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| semi-transparent. During reading, laser
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| | shrinked to the desired size. This method
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| collects data from bottom layer first,
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| | is much more effective as whole frame is
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| and then switches to the second layer.
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| | used for useful data, while in Letterbox
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| This allows doubling the capacity, up to
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| | large part of the frame is used to store
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| 9GB. It is easy to recognize
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| | black pixels only. As a result,
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| double-layered disks - they have silver
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| | anamorphic mode has better details and
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| shade of working surface, while
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| | sharper picture.Audio data can be stored
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| single-layered disk appears gold. Most
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| | in various formats: LPCM, Dolby Pro
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| video releases are printed on
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| | Logic, Dolby Digital, Dolby Digital EX
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| double-layered disks.Apart from that,
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| | and DTS.LPCM (linear pulse code
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| both sides of DVD can be used to store
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| | modulation) is uncompressed stereo or
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| data. The possibility of making
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| | mono soundtrack. It is usually used in
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| double-sided disks arise from the fact
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| | musical video clips and movies where
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| that the protective layer for DVD is only
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| | sound clarity is important. Same format
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| half of that for CD, that is, 0.6mm
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| | is used for generic Audio CDDolby Pro
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| instead of 1.2mm. So, in order to keep
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| | Logic is special type of soundtrack that
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| compatibility with older format,
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| | can be split into 4 channels for surround
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| single-sided DVD disks have additional
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| | sound. Nowadays this format is
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| plastic added to them to achieve 1.2mm
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| | uncommon.Dolby Digital (AC-3) is fully
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| thickness. Of course, it is not a problem
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| | digital sound compression format; it can
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| to put additional layer instead of 0.6mm
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| | be split into up to 6 independent
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| of plain plastic. This wasn't possible
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| | channels. Unlike Dolby Pro Logic, each
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| with CDs as they are thick enough
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| | channel is recorded on separate physical
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| already.DVD - the history of conflictIn
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| | track.Dolby Digital EX is more advanced
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| 1997 several large manufacturers of
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| | version of Dolby Digital. Supports up to
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| electronic equipment established
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| | 8 independent channels.DTS (Digital
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| organization called DVD-Forum (earlier
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| | Theater System) is another digital audio
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| known as DVD Consortium) in order to
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| | compression format, introduced by Steven
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| develop single standard for new
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| | Spielberg as an alternative to Dolby
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| generation of disks, as CD technology was
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| | Digital. DTS provides more quality than
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| becoming less and less sufficient.Despite
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| | Dolby Digital due to lower compression.
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| many debates and lots of technologies
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| | That, of course, leads to bigger size of
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| claiming to be the best, the final
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| | the soundtrack itself, which occupy more
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| decision was made and DVD (with eight
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| | disk space. It also requires special
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| types of it) standard was established. It
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| | receiver to be decoded. Because of these
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| was soon followed by DVD-Video
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| | reasons DTS disks usually does not have
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| standard.However, when it came to
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| | any bonus materials but have LPCM
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| standards for recordable and rewritable
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| | soundtrack. This soundtrack is included
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| disks, several large companies started to
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| | to allow users without special receiver
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| push their own formats DVD+R and DVD+RW.
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| | to listen to the sound (stereo only,
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| These companies founded their own
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| | though). Because of all these DTS disks
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| coalition called DVD+RW Alliance. The
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| | are much less common compared to Dolby
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| most interesting part was the fact that
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| | Digital. Usually DTS disks with improved
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| different branches of formats were not
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| | video quality (and without bonus
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| compatible with each other.Apart from
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| | materials) are called SuperBit. Both DTS
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| that, Panasonic also contributed to the
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| | and Dolby Digital (EX) are also used in
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| mess by developing DVD-RAM standard. This
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| | cinemas.Some of the largest drawbacks of
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| standard was faster and more reliable,
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| | DVD-Video are its various copy protection
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| but it was compatible only with DVD-RAM
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| | measures, which were added because of the
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| devices.The ones who suffered the most
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| | pressure from film companies. At first
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| from this mess were common users, as they
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| | these measures provided lots of nuisance
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| were forced to make a difficult choice of
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| | for users, but eventually every DVD
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| preferred technology.For that reason many
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| | protection was hacked. This process was
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| people didn't rush for DVD and kept their
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| | also assisted by equipment manufacturers
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| data on good old CD-Rs and CD-RWs.The war
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| | who simply didn't support most annoying
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| of standards was ended by Sony, which
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| | protection measures.One of the most
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| made DVD drive capable of reading both
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| | annoying of such measures was "Regional
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| DVD-RW and DVD+RW. This device instantly
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| | Protection" . The world was divided into
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| became popular even in spite of its
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| | 8 zones, and each DVD player was supposed
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| double price compared with
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| | to have information about its zone. The
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| single-standard drives. Sony soon was
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| | same was made for DVDs, and thus DVDs
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| followed by other manufacturers and the
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| | from one zone could only be played on
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| ability to read both types of disks soon
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| | players from the same zone. User was
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| became a standard for any DVD drives.
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| | allowed to change zone for the player few
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| This was the beginning of the DVD era for
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| | times only, and the last of selected
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| PC users.Unfortunately, there also were
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| | zones was locked in the player
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| lots of disagreements during development
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| | forever.This trick was invented in order
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| of single standard for digital audio,
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| | to be able to assign different price in
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| DVD-Audio. Two technologies compete for
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| | each region, depending on income level.
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| the title of Audio CD heir: a partially
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| | Besides, movie might be released in
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| compatible with Audio CD technology from
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| | different times in different countries.
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| Philips and Sony, and a standalone
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| | For example, in Africa the movie might
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| Toshiba's standard. Toshiba won, but
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| | just hit cinemas and in USA it might
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| Philips and Sony didn't give up and
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| | already be available on DVD. So regional
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| released their own format without
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| | protection was supposed to stop people
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| DVD-Forum support. This format was called
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| | from buying DVDs in USA and selling them
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| Super Audio CD (SACD). At the moment both
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| | in Africa.Unfortunately, this protection
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| formats are not selling particularly well
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| | didn't bring anything but troubles. Many
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| and are not known in some countries at
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| | travelers were not able to play disk
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| all.Types of DVDLet's move to DVD itself.
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| | purchased overseas. Buying disks over the
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| DVD is the most common format nowadays.
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| | internet or from EBay also became a
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| At the moment DVD comes in 8 flavors:
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| | problem. Apart from that, some movies
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| DVD-1, DVD-2, DVD-3, DVD-4, DVD-5, DVD-9,
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| | were released in certain countries
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| DVD-10 and DVD-18. The difference is in
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| | only.Many manufacturers considered these
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| the capacity, which is denoted by the
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| | implications and started to provide means
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| number in the name (value is rounded).The
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| | of switching off regional protection for
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| most common formats are DVD-5 and DVD-9.
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| | their devices. Chinese manufacturers
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| These are single- and double layered
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| | basically abandon this protection at
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| single sided disks, respectively. DVD-5
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| | all.But uncontrolled distribution of DVDs
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| holds 4.7 GB of data and DVD-9 is able to
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| | wasn't the only thing that movie makers
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| contain up to 8.5 GB. These disks are
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| | were against. Illegal copying was much
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| used for most software and video
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| | bigger problem for them, especially given
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| releases.DVD-10 is double sided single
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| | the fact that digital information can be
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| layered disk (9.4 GB) and DVD-18 is
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| | copied endlessly without any loss of
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| double sided double layered disk (17GB).
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| | quality. To prevent that from happening,
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| This two types of DVD are much less
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| | manufacturers included special CSS
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| common. All four formats mentioned above
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| | (content scrambling system) technology in
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| have same diameter of the disk - 12cm.
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| | DVD-Video standard. CSS basically encrypt
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| Another type of disk to mention here is
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| | all disks content and the key for
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| DVD-14, which is double sided disk with
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| | decryption is available only for
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| one side single- and the other one
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| | DVD-Player or special viewing program.
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| double-layered. This type of disk holds
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| | Simply copying the disk will make the
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| 12.32GB of data.DVD-1, DVD-2, DVD-3 and
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| | copy completely useless.But manufacturers
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| DVD-4 are miniDVD. Their diameter is 8cm
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| | forgot to include support for Unix system
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| but otherwise they are completely
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| | and playback was available only for
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| compatible with standard drives. As with
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| | Windows and MacOS. This issue was solved
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| full-size disks there are single sided
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| | by Jon Johansen, who wrote DeCSS program
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| single layered disk (DVD-1, 1.36 GB),
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| | for Unix that easily bypassed CSS
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| single sided double layered disk (DVD-2,
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| | protection. Developers of CSS were
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| 2.48 GB), double sided single layered
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| | enraged with that and sued Jon. They
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| (DVD-3, 2.72 GB) and double sided double
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| | wanted to stop DeCSS from spreading and
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| layered disk (DVD-4, 4.95 GB). All these
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| | put Jon in prison, however, this case
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| disks, except DVD-1, are quite
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| | sparked lots of support movements around
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| uncommon.Types of DVD dataEach DVD disk
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| | the world. Activists even printed DeCSS
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| is able to hold various types of data.
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| | code on t-shirts. Finally, Jon was
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| DVD can be used to watch movies
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| | declared not guilty and his program laid
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| (DVD-Video), store software (DVD-Data)
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| | a foundation for many DVD copy utilities
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| and to listen to the music
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| | all over the world.In general, DVD format
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| (DVD-Audio).DVD-Data DVD-DATA is used to
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| | was successful and, despite some issues
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| store computer data on DVD. Basically it
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| | with regional protection, has spread all
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| is the same CD-ROM, but with much bigger
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| | over the world and almost replaced VHS
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| capacity, and it is used the same way as
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| | tapes.SummaryDVD is not a new format
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| CD-ROM is. However DVD-DATA is more
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| | anymore and there are actually new
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| convenient as a storage medium due to its
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| | formats already that aim to replace it.
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| large capacity. Most modern programs
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| | Someone could ask why does he or she
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| doesn't fit on single CD, for example,
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| | needs to be familiar with DVD if there is
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| computer games and Linux packages often
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| | something new coming? The answer to this
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| need more than 10 CDs. In case with DVD
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| | lies in the fact that DVD provides
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| one or two disks are usually more than
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| | foundation for most new technologies, for
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| enough. At the moment software is usually
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| | example HD-DVD or Blue Ray. And if
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| released on both CD and DVD, as not
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| | someone became familiar with underlying
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| everyone has DVD drive yet. But it is
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| | principles once, it won't be a problem to
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| clear that CD versions soon will
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| | switch to something new later.Artem
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| disappear.DVD-VideoCurrently this is the
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| | Chlegov is a editor and writer for - a
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| most common type of DVD data, the one
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| | DVD software review website.
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