DVD+R
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A DVD+R is a once-writable optical disc with 4.7 GB (4.377 GiB) of storage capacity (more precisely, 2295104 sectors of 2048 bytes each). It has slightly less storage capacity than the DVD-R (4.382 GiB). The format was developed by a coalition of corporations, known as the DVD+RW Alliance, in mid 2002. 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 2008-01-25.[citations needed]
In October of 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).[citations needed]
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 "minus" and the "plus" format, though 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 than the LPP (Land Pre Pit) system used by DVD-R, which makes the ADIP system more accurate at higher speeds. 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.[1]
Like other "plus" media, it is possible to change the book type to increase the compatibility of DVD+R media.[citation needed]
As of 2007, the market for recordable DVD technology shows little sign of settling down in favor of either the "dash" or "plus" formats, which is mostly the result of the increasing numbers of dual-format devices that can record to both formats; it has become very difficult to find new devices that can only record to one of the formats. However, because the DVD-R format has been in use since 1997, it has had a five-year lead on DVD+R. As such, older or cheaper DVD players (up to 2004 vintage) are more likely to favor the DVD-R standard exclusively[2], and when creating DVDs for distribution (where the playing unit is unknown or older) the DVD-R format would normally be preferable.
On 2008-01-25, DVD6C officially accepted DVD+R and DVD+RW by adding them to its list of licensable DVD products.[3]
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[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.
| 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
- ^ How To Choose CD/DVD Archival Media, Patrick McFarland, adterrasperaspera.com, October 30th, 2006
- ^ "What is DVD?". Retrieved on 2008-07-23.
- ^ "DVD6C Announces New Licensing Program". Retrieved on 2008-01-25.
