DVD+R

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

Contents

[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 of the initial advocacy was from Sony). The DVD+R format competes with the DVD-R format, which is developed by the DVD Forum. The DVD Forum initially did not approve of the DVD+R format and 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.[citation needed]

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

On 25 January 2008, 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 carry up to 4.7 GB of data, approximately the same as DVD-R.[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 may 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” and the “plus” format, although most users would not notice the difference. One example is that the DVD+R style Address In Pregroove (ADIP) system of tracking and speed control is less susceptible to interference and error, which makes the ADIP system more accurate at higher speeds than the Land Pre Pit (LPP) 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
DVD-R (SL) 2,298,496 4,707,319,808 4.7
DVD+R (SL) 2,295,104 4,700,372,992 4.7
DVD-R DL 4,171,712 8,543,666,176 8.5
DVD+R DL 4,173,824 8,547,991,552 8.5
SL / DL – Single/Dual layer

[edit] Speed

Drive speed Data rate (MB/s) Data rate (Mbit/s) Write time for Single Layer DVD+R
1X 1.32 MB/s 10.56 Mbit/s 60 minutes
2X 2.64 MB/s 21.12 Mbit/s 30 minutes
4X 5.28 MB/s 42.24 Mbit/s 15 minutes
8X 10.56 MB/s 84.48 Mbit/s 7.5 minutes
16X 21.12 MB/s 168.96 Mbit/s 3.75 minutes
20x 26.40 MB/s 211.20 Mbit/s 3.00 minutes
22x 29.04 MB/s 232.32 Mbit/s 2.73 minutes
24x[6] 31.68 MB/s 253.44 Mbit/s 2.50 minutes

[edit] See also

[edit] References

  1. ^ a b "DVD6C Announces New Licensing Program". http://www.dvd6cla.com/news_20080125.html. Retrieved 2008-01-25. 
  2. ^ "What is DVD?". http://www.videohelp.com/dvd. Retrieved 2008-07-23. 
  3. ^ "Understanding DVD". Optical Storage Technology Association. 2004. http://www.osta.org/technology/dvdqa/dvdqa6.htm. Retrieved 2008-09-06. 
  4. ^ How To Choose CD/DVD Archival Media, Patrick McFarland, adterrasperaspera.com, October 30th, 2006
  5. ^ "Increased compatibility: DVD bitsetting". http://www.cdfreaks.com/reviews/Increased-compatibility-DVD-bitsetting/. Retrieved 2008-09-15. 
  6. ^ "Sony’s “miracle” DVD burner hits 24x write speed". http://www.tgdaily.com/hardware-features/41556-sony%E2%80%99s-%E2%80%9Cmiracle%E2%80%9D-dvd-burner-hits-24x-write-speed. Retrieved 2009-02-26. 

[edit] External links

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