Nokia Data Cable ,
History
In 1993, two high-definition optical storage formats were being developed. One was the MultiMedia Compact Disc (MMCD), backed by Philips and Sony, and the other was the Super Density (SD) disc, supported by Toshiba, Time Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC.
Optical disc authoring
Optical disc
Optical disc driv , headrest dvd monitor .
Optical disc authorin , keyboard integrated mouse .
Authoring software
Recording technologies
Recording modes
Packet writing
Optical media types
Blu-ray Disc (BD): BD-R, BD-RE
DVD: DVD-R, DVD+R, DVD-R DL, DVD+R DL, DVD-RW, DVD+RW, DVD-RW DL, DVD+RW DL, DVD-RW2, DVD-RAM, DVD-D, HVD
Compact Disc (CD): Red Book, CD-ROM, CD-R, CD-RW, 5.1 Music Disc, SACD, PhotoCD, CD Video (CDV), Video CD (VCD), SVCD, CD+G, CD-Text, CD-ROM XA, CD-i
Universal Media Disc (UMD)
Enhanced Versatile Disc (EVD)
Forward Versatile Disc (FVD)
Holographic Versatile Disc (HVD)
HD DVD: HD DVD-R, HD DVD-RW, HD DVD-RAM
High-Definition Versatile Disc (HDVD)
High definition Versatile Multilayer Disc (HD VMD)
VCDHD
GD-ROM
MiniDisc (MD) (Hi-MD)
Laserdisc (LD)
Video Single Disc (VSD)
Ultra Density Optical (UDO)
Stacked Volumetric Optical Disk (SVOD)
Five dimensional discs (5D DVD)
Standards
Rainbow Books
File systems
ISO 9660
Joliet
Rock Ridge
El Torito
Apple ISO 9660 Extensions
Universal Disk Format (UDF)
Mount Rainier
Further reading
History of optical storage media
High definition optical disc format war
This box: view talk edit
Representatives of the SD camp approached IBM, asking for advice on the file system to use for their disk as well as looking for support for their format for storing computer data. A researcher from IBM’s Almaden Research Center received that request and also learned of the MMCD development project. Wary of being caught in a repeat of the costly videotape format war between VHS and Betamax in the 1980s, he convened a group of computer industry experts, including representatives from Apple, Microsoft, Sun, Dell, and many others. This group was referred to as the Technical Working Group, or TWG. The TWG voted to boycott both formats unless the two camps agreed on a single, converged standard. Lou Gerstner, president of IBM, was recruited to apply pressure on the executives of the warring factions. Eventually, the computer companies won the day, and a single format, now called DVD, was agreed upon. The TWG also collaborated with the Optical Storage Technology Association (OSTA) on the use of their implementation of the ISO-13346 file system (known as Universal Disk Format [UDF]) for use on the new DVDs.
Philips and Sony decided it was in their best interest to avoid another format war over their MultiMedia Compact Disc, and agreed to unify with companies backing the Super Density Disc to release a single format with technologies from both. The specification was mostly similar to Toshiba and Matsushita’s Super Density Disc, except for the dual-layer option (MMCD was single-sided and optionally dual-layer, whereas SD was single-layer but optionally double-sided) and EFMPlus modulation. EFMPlus was chosen due to its great resilience against disc damage, such as scratches and fingerprints. EFMPlus, created by Kees Immink (who also designed EFM), is 6% less efficient than the modulation technique originally used by Toshiba, which resulted in a capacity of 4.7 GB, as opposed to the original 5 GB. The result was the DVD specification, finalized for the DVD movie player and DVD-ROM computer applications in December 1995. Toshiba first introduced the DVD Video format in Japan in November 1996, in the United States in March 1997 (test marketed), in Europe in 1998, and in Australia in 1999. In May 1997, the DVD Consortium was replaced by the DVD Forum, which is open to all other companies. DVD specifications created and updated by DVD Forum are published as so-called DVD Books (e.g. DVD-ROM Book, DVD-Audio Book, DVD-Video Book, DVD-R Book, DVD-RW Book, DVD-RAM Book, DVD-AR Book, DVD-VR Book, etc). Some specifications for mechanical, physical and optical characteristics of DVD optical disks can be downloaded as freely available standards from ISO website. There is also DVD+RW Alliance, which publish competing DVD specifications such as DVD+R, DVD+R DL, DVD+RW or DVD+RW DL. These DVD formats are also ISO standards.
Etymology
The official DVD specification documents have never defined the initialism DVD. Usage in the present day varies, with Digital Versatile Disc, Digital Video Disc, and DVD being the most common.
DVD was originally used as an initialism for the unofficial term digital videodisk.
It was reported in 1995, at the time of the specification finalization, that the letters officially stood for Digital Versatile Disc (due to nonvideo applications).
However, the text of the press release announcing the specification finalization only refers to the technology as “DVD”, making no mention of what (if anything) the letters stood for.
A newsgroup FAQ written by Jim Taylor (a prominent figure in the industry) claims that four years later, in 1999, the DVD Forum stated that the format name was simply the three letters “DVD” and did not stand for anything.
The DVD Forum website has a section called “DVD Primer” in which the answer to the question, “What does DVD mean?” reads, “The keyword is ‘versatile.’ Digital Versatile Discs provide superb video, audio and data storage and accessll on one disc.”
DVD capacity
Capacity and nomenclature
Designation
Sides
Layers
(total)
Diameter
Capacity
(cm)
(GB)
(GiB)
DVD-1
SS SL
1
1
8
1.46
1.36
DVD-2
SS DL
1
2
8
2.66
2.47
DVD-3
DS SL
2
2
8
2.92
2.72
DVD-4
DS DL
2
4
8
5.32
4.95
DVD-5
SS SL
1
1
12
4.70
4.38
DVD-9
SS DL
1
2
12
8.54
7.95
DVD-10
DS SL
2
2
12
9.40
8.75
DVD-14
DS DL/SL
2
3
12
13.24
12.33
DVD-18
DS DL
2
4
12
17.08
15.90
SS = Single-sided; DS = Double-sided; SL = Single-layer; DL = Dual-layer.
The basic types of DVD are referred to by a rough approximation of their capacity in gigabytes. In draft versions of the specification, DVD-5 indeed held five gigabytes, but some parameters had to be changed later on to address technical challenges, so the capacity decreased.
The 12 cm type is a standard DVD, and the 8 cm variety is known as a mini-DVD. These are the same sizes as a standard CD and a mini-CD, respectively. The capacity by surface (MiB/cm) varies from 6.92MiB/cm in the DVD-1 to 18.0 MiB/cm in the DVD-18.
Note: As with hard disk drives, in the DVD realm, gigabyte and the symbol GB are usually used in the SI sense, i.e., 109 (or 1,000,000,000) bytes. For distinction, gibibyte (with symbol GiB) is used, i.e., 230 (or 1,073,741,824) bytes. Most computer operating systems display file sizes in gibibytes, mebibytes, and kibibytes, labeled as gigabyte, megabyte, and kilobyte, respectively.
Each DVD sector contains 2418 bytes of data, 2048 bytes of which are user data.
Size comparison: a 12 cm DVD+RW and a 19 cm pencil.
There is a small difference in storage space between “+” and “-” (hyphen) formats:
Capacity differences of writable DVD formats
Type
Sectors
Bytes
MB
MiB
GB
GiB
DVD SL
2,298,496
4,707,319,808
4,707.320
4,489.250
4.707
4.384
DVD+R SL
2,295,104
4,700,372,992
4,700.373
4,482.625
4.700
4.378
DVD DL
4,171,712
8,543,666,176
8,543.666
8,147.875
8.544
7.957
DVD+R DL
4,173,824
8,547,991,552
8,547.992
8,152.000
8.548
7.961
Technology
Internal mechanism of a DVD-ROM Drive.
DVD-RW Drive operating with the protective cover removed.
DVD uses 650 nm wavelength laser diode light as opposed to 780 nm for CD. This permits a smaller pit to be etched on the media surface compared to CDs (0.74 m for DVD versus 1.6 m for CD), allowing for a DVD’s increased storage capacity.
In comparison, Blu-ray, the successor to the DVD format, uses a wavelength of 405 nm, and one dual-layer disc has a 50 GB storage capacity.
Writing speeds for DVD were 1, that is, 1350 kB/s (1318 KiB/s), in the first drives and media models. More recent models, at 18 or 20, have 18 or 20 times that speed. Note that for CD drives, 1 means 150 KiB/s (153.6 kB/s), approximately 9 times slower.
DVD drive speeds
Drive speed
Data rate
~Write time* (min)
(Mbit/s)
(MB/s)
(MiB/s)
SL
DL
1
10.80
1.35
1.29
61
107
2
21.60
2.70
2.57
31
54
2.4
25.92
3.24
3.09
25
45
2.6
28.08
3.51
3.35
23
41
4
43.20
5.40
5.15
15
27
6
64.80
8.10
7.72
10
18
8
86.40
10.80
10.30
8
13
10
108.00
13.50
…
