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DVD+R

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DVD+R is a format for optical data storage. It is similar to, but incompatible with, the earlier DVD-R standard. A DVD+R is a write-once optical disc with 4.7 billion bytes of storage, generally used for nonvolatile data storage or video applications.

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[edit] History

The DVD+R format was developed by a coalition of corporations — now known as the DVD+RW Alliance — in mid 2002 (though most initial advocacy was from Sony). Since the DVD+R format is a competing format to the DVD-R format, which is developed by the DVD Forum, it had not been approved by the DVD Forum, which claimed that the DVD+R format was not an official DVD format until January 25, 2008.[1]

In October 2003, it was demonstrated that double layer technology could be used with a DVD+R disc to nearly double the capacity to '8.5 GB' per disc. Manufacturers have incorporated this technology into commercial devices since mid-2004 (see DVD+R DL).[citation needed]

As of 2007, the recordable DVD market still shows little sign of settling down in favor of either the "dash" or "plus" formats. Since almost all new DVD writers can record to both formats, this is not an issue for most people. However when creating DVDs for distribution (where the playing unit is unknown or older) using DVD-R format would be preferable because most older (up to 2004) standalone DVD video players and DVD ROM drives only support the earlier DVD-R standard.[2],

On 2008-01-25, DVD6C officially accepted DVD+R and DVD+RW by adding them to its list of licensable DVD products.[1]

[edit] Technical details

DVD+R discs have 4.7 GB or 4.377 GiB (DVD-R has 4.382 GiB) of storage capacity (more precisely, 2295104 sectors of 2048 bytes each[3]). Unlike DVD+RW discs, DVD+R discs can only be written to once. Because of this, DVD+R discs are suited to applications such as nonvolatile data storage, audio, or video. This can cause confusion because the DVD+RW Alliance logo is a stylized "RW". Thus, a DVD+R disc can have the RW logo, but it is not rewritable.

The DVD+R format is divergent from the DVD-R format. Hybrid drives that can handle both, often labeled "DVD±RW", are very popular since there is not a single standard for recordable DVDs. There are a number of significant technical differences between the "dash" (it's not a minus symbol) and the "plus" format, although most users would not notice the difference. One example is the DVD+R style ADIP (ADdress In Pregroove) system of tracking and speed control being less susceptible to interference and error which makes the ADIP system more accurate at higher speeds than the LPP (Land Pre Pit) system used by DVD-R. In addition, DVD+R(W) has a more robust error management system than DVD-R(W), allowing for more accurate burning to media independent of the quality of the media. Additional session linking methods are more accurate with DVD+R(W) versus DVD-R(W), resulting in fewer damaged or unusable discs due to buffer under-run and multi-session disks with fewer PI/PO errors.[4]

Like other "plus" media, it is possible to change the book type to increase the compatibility of DVD+R media. This is also known as bitsetting.[5]

[edit] Recordable DVD capacity comparison

For comparison, the table below shows storage capacities of the four most common DVD recordable media, excluding DVD-RAM. (SL) stands for standard single-layer discs, while DL denotes the double-layer variants. See articles on the formats in question for information on compatibility issues.

DVD capacity
Disk Type Data sectors
(2,048 B each)
Capacity
bytes GB GiB
DVD-R (SL) 2,298,496 4,707,319,808 4.7 4.384
DVD+R (SL) 2,295,104 4,700,372,992 4.7 4.378
DVD-R DL 4,171,712 8,543,666,176 8.5 7.957
DVD+R DL 4,173,824 8,547,991,552 8.5 7.961
SL / DL – Single/Dual layer

[edit] Speed

Drive speed Data rate Write time for Single Layer DVD+R
1X 1.32 MB/s 60 minutes
2X 2.64 MB/s 30 minutes
4X 5.28 MB/s 15 minutes
8X 10.56 MB/s 7.5 minutes
16X 21.12 MB/s 3.75 minutes

[edit] See also

[edit] References

[edit] External links