DVD Wiki
All you have to know about DVD's is here. Know more.
DVD is today’s most popular optical disc storage media format which means “Digital Versatile Disc” and sometimes also known as “Digital Video Disc”. Just like any other video discs like compact discs or CD, it is also used as storage—usually for data and videos. A DVD can store a larger data compared to a compact disc which is more ideal for storing multiple movies and large data.
However, the term DVD can also be defined according to its use as storage. Here are some of the variations:
DVD-ROM (Read Only Memory) – Data primarily stored in this disc can only be read but not recordable (non-writeable).
DVD-R
DVD+R – Data can be stored here once but can’t be erased once a data is already recorded or written. Logically, it will become DVD-ROM once written.
DVD-RW
DVD+RW
DVD-RAM – Data can be recorded, erased, and re-recorded many times in these discs.
Standard lasers used for DVD has a red color and its wavelength measures 650 nm. DVDs that are ready to view are classified according to into different types depending on the content.
DVD Video – contains recorded videos in such as full-length movies, concerts, music videos, and is usually for commercial use.
DVD Audio – contains high-fidelity audio contents (no video), which is used for songs and other kinds of music format.
Data DVD – contains different kinds of data from audio, video, image files, and other kinds of supported data.
Right now, DVDs are continually evolving into even much better formats. HD-DVD or high-definition DVDs are already in use. In order to distinguish, they call the standard DVD as SD-DVD meaning standard-definition DVD, apart from HD-DVD (Blu-ray).
1993
MMCD Team – MMCD or Multimedia Compact Disc was developed by this team with support from Philips and Sony.
SD Team – SD or Super Density disc was developed by this team on the same year with support from Toshiba, Hitachi, JVC, Time Warner, Mitsubishi Electric, Matsushita Electric, Thomson, and Pioneer.
The SD Team asked advice from IBM about their development where they are also asking support for the file format of their disk where you can store data. Some IBM researchers gained knowledge about the SD project and they also got news about the MMCD project.
TWG - Being prudent about possible clash between the two file formats just like what happened with the Betamax and VHS in the 80’s, IBM assembled a group called Technical Working Group or TWG which includes experts in the computer industry like Dell, Microsoft, Apple, Sun, and many more.
TWG pressured the two warring formats (MMCD and SD) on agreeing with only one format instead of using both their formats. In short, TWG won the proposal which gives birth to the DVD format. DVD format was eventually issued a UDF or Universal disk Format (ISO-13346) by Optical Storage Technology Association in order for the DVDs to be used.
The DVD format is more closely-related to the former SD format because it has the option of being double-sided. With certain improvements like high protection from scratch, DVD was finalized for its debut use.
1995
DVD was first used for playing movies and for DVD-ROM applications for computers which happened in December.
1996
In Japan, DVD-Video was first introduced.
1997
DVD was test-marketed in the United States in March of this year. The DVD Forum replaced the DVD Consortium.
1998
DVD was introduced in Europe.
1999
DVD was introduced in Australia.
And the rest was history. Now we are all enjoying DVDs!
DVD as Digital Visual Disc – this term stands for the acronym DVD when it was still unofficial.
DVD as DVD – according to the DVD Forum in 1999, the name of the format is DVD and it stands for nothing but DVD itself.
DVD as Digital Video Disc – a present day definition of the term DVD as interchanged with Digital Versatile Disc.
DVD as Digital Versatile Disc – in 1995, this was considered as the official term that stands for DVD. Until now, it has been considered as the true meaning of the acronym because of the word “versatile” which best fit the ability of the format to store not only visual media but also quality audio and data.
Mini-DVD – are DVDs that are smaller than the standard DVD. These DVDs are 8 cm in diameter. Below are the four types of mini-DVDs with different capacities:
SS SL – 1 side, 1 layer, 1.36 gigabytes
SS DL – 1 side, 2 layers, 2.47 gigabytes
DS SL – 2 sides, 2 layers, 2.72 gigabytes
DS DL – 2 sides, 4 layers, 4.95 gigabytes
Standard DVD – are DVDs that we usually use today which measures 12 cm in diameter. Below are the five types of standard DVDs with different capacities:
SS SL – 1 side, 1 layer, 4.37 gigabytes
SS DL – 1 side, 2 layers, 7.95 gigabytes
DS SL – 2 sides, 2 layers, 8.74 gigabytes
DS DL/SL – 2 sides, 3 layers, 12.32 gigabytes
DS DL – 2 sides, 4 layers, 15.90 gigabytes
Writable DVD
DVD-R SL – 4.384 gigabytes
DVD+R SL – 4.378 gigabytes
DVD-R DL – 7.957 gigabytes
DVD+R DL – 7.961 gigabytes
Image of diodes
WRITING SPEED CHART
Laser diode – the amplified light or laser used in reading or writing DVDs located inside DVD players or DVD recorders. These are the comparable wavelengths used in different disk formats:
CD – 780 nm
DVD – 650 nm
HD-DVD – 405 nm
Writing Speed
The very first models of the writable discs have a write speed of 1x which is equivalent to 1.35MB per second. Nowadays, the latest models can be as fast as 18x or 2x in speed. (Please refer to the chart on the left)
(DVD ROM)
With its name, these are DVDs which are used to store digital video and this has been the most used forms of DVD by consumers. DVD-Video specifications of certain discs usually require a DVD drive and also an MPEG2 decoder. Examples where a DVD-Video can be played are DVD Players and DVD computer drive supported by DVD software. DVD movies that are released commercially are encoded using a combination of MPEG2 compressed video and different formats of audio.
(DVD-A)
Audio with very high-fidelity are contained in a DVD Audio. These are not the DVD Video formats that contain music videos and concerts but these are just for sounds. They contain no video. It was first released commercially in 2000 and had great competition with the SACD (Super Audio CD) but they both attained no great position on the market.