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Eug Currently there are many writeable and rewriteable DVD formats on the mar ket, and this can be confusing to the average consumer. These DVD format s include: DVD-RAM DVD-R DVD-RW DVD+R DVD+RW DVD-RAM DVD-RAM is a sanctioned format of the DVD Forum, a consortium of companie s involved in the development of DVD standards. DVD-RAM was a format ori ginally aimed primarily as a data solution, but it is now becoming popul ar as a video format used by some brands of standalone (non-PC) DVD reco rders. DVD-RAM is a very robust data storage solution, theoretically all owing greater than 100000 rewrites per disc. Early PC-based DVD-RAM recorders used 26 GB discs (or double-sided 52 G B discs), but current drives also use 47 GB discs (or double-sided 94 GB discs). DVD-RAM discs are traditionally housed within cartridges, so that the media is well-protected. Originally, the cartridges could not b e opened, but newer Type II and Type IV cartridges can be opened, an imp ortant feature for those who wish to read these discs in DVD-RAM compati ble DVD-ROM drives or standalone DVD players. In addition, some DVD-RAM discs are now sold without cartridges. In addition to support of the usual DVD UDF formats, DVD-RAM also allows fully integrated OS-level random read/write access similar to hard drive s, with both Windows XP (with FAT32) and Mac OS X (with FAT32 or HFS+), as well as on-the-fly write verification. The main drawback of the DVD-RAM format is its limited read compatibility by DVD-ROM drives and standalone DVD players. DVD-RAM read support with these units is increasing however, partially because of the increasing popularity of home standalone DVD-RAM recorders in home theatre systems. DVD-R and DVD-RW DVD-R and DVD-RW are also both formats of the DVD Forum. Both formats gen erally use 47 GB discs, although some professional DVD-R drives use 39 5 GB discs. DVD-R is a write-once recordable format which allows excellent compatibil ity with both standalone DVD players and DVD-ROM drives. There are two m ain types of DVD-R discs: DVD-R for General Use and DVD-R for Authoring. Most consumer DVD-R burners use the cheaper General Use discs, while so me professional burners use Authoring discs. The correct media type appr opriate for the recorder must be used when burning a DVD-R. However, onc e written, the discs should be readable in either drive type. The majority of standalone DVD players will play video recorded on DVD-RW discs, but the compatibility is not as hig h as with DVD-R. Some older DVD-R recorders were not capable of writing t o DVD-RW discs (although some were able to read DVD-RW discs burned with other drives). DVD-RW and DVD-R have heavy penetration into the professional multimedia market as well as the general consumer market. For instance, the Apple S uperDrive, found in many pro and consumer Mac computers, is simply a DVD -R/DVD-RW (and CD-R/CD-RW) capable burner. DVD+R and DVD+RW These two formats are backed by the DVD+RW Alliance. While these formats are not supported by the DVD Forum, several members of the DVD+RW Allian ce are also members of the DVD Forum. These discs are very similar to DV D-R and DVD-RW in design, usage, and compatibility. DVD+RW, like DVD-RW, is a rewriteable 47 GB format, and overall it has s imilar functionality to DVD-RW. The level of compatibility of standard D VD+RW discs in standalone DVD players is similar to that of DVD-RW. The rewritability of DVD+RW is also said to be similar to that of DVD-RW, al lowing up to 1000 rewrites. One potential advantage of the DVD+RW format is Mount Rainier (DVD+MRW) d rag-and-drop file access support planned for Longhorn, a future version of Windows slated for release in 2005. Older DVD+RW drives do not suppor t this function, but newer drives may. While DVD+MRW is arguably not as robust a data solution as DVD-RAM, DVD+MRW potentially will offer higher read compatibility in current DVD-ROM drives. DVD+R is a format that was introduced to consumers in early 2002. The fir st generation +RW recorders did not support DVD+R recording, and likely cannot be upgraded to do so. However, all current models of DVD+RW recor ders also support DVD+R recording. Compatibility of +R discs in standalo ne DVD players is similar to that of DVD-R. Support of combinations of several of the formats are available in many c urrent drives. Recorders that conform to the DVD Forums DVD Multi Recor der standard will record to DVD-RAM, DVD-R, and DVD-RW. Other recorders also record to both +R/+RW and DVD-R/DVD-RW. Some drives are even able t o record to all of the DVD Forum and DVD+RW Alliance formats. In additio n to the various DVD formats, most drives will also record to CD-R and C D-RW discs. The choice largely depends on one's us age environment and preferences. DVD-RAM discs cannot be used in most standalone DVD players and DVD-ROM d rives, and this has historically made this format less attractive for th e average home user. However, the integrated OS-level drag-and-drop read /write data support of DVD-RAM makes it very attractive for some users, especially now that most current DVD-RAM burners also support DVD-R burn ing for video applications. DVD-RAM capable PC drives will also be ideal for those whom already own DVD-RAM based camcorders or standalone DVD-R AM recorders. DVD-R/DVD-RW drives currently have the highest market penetration, both w ith PCs and Macs. As previously mentioned, DVD-R enjoys high compatibili ty with standalone DVD players. In addition, the low cost of DVD-RW is a ttractive to many for backup purposes. Furthermore, most standalone DVD players will read DVD-RW as well, although the compatibility rate is low er than with DVD-R. DVD+R/DVD+RW is gaining market share, and these discs appear to have simi lar compatibility on standalone DVD players as DVD-R/DVD-RW discs. Simil arly, current functionality with these drives is similar to DVD-R/DVD-RW drives, both for data and for video applications, and they likely are e qually reliable. And of course, as mentioned earlier, many multiformat drives exist (albei t often at higher cost). Most external DVD recordable drives are essentially IDE drives with USB 2 or Firewire 1394a bridges and custom housing. These drives can be purchased as complete drives, bu t one may purchase a standard IDE DVD burner for use in a third party US B 2 or Firewire enclosure. Besides ease of installation, an external dri ve offers the ability to use a single drive with multiple computers. Compatibility of external drives is not guaranteed with all software, how ever. Some laptops now include DVD burners as the primary optical drive. I f one does not have an internal DVD burner, one may use an external driv e, connected to a Firewire or USB 2 port on the laptop. This port can be either built-in or on an add-in PCMCIA adapter card. The fastest desktop burners (as of September 2003) are 8X for DVD+/-R and 4X for DVD+/-RW. Laptop DVD burners usually have a 2X maximum DVD burn speed. Can I use a DVD burner to make backups of commercial DVDs? Making backups of DVDs one does not own or making backups for resale is i llegal. However, it may be legal to make backups of ones own DVDs for p ersonal use. For example, some families may wish to backup childrens DV Ds, in order to protect them from damage caused by mishandling. Many may be familiar with the process of CD backups, which simply involve s a direct copy of a CD to a CD-R. Unfortunately, the backup process for DVDs is usually a much more complex process, for a number of reasons. In order to backup the video data on a DVD (which is located in the VIDEO_TS folder), one must first decrypt the disc to a computers hard drive. Various software exists on various platforms to perform the decryption. Both layers of dual-layer discs are readable by a DVD players laser from one side of the disc. Thus, in order to backup a dual-layer disc, one must either compress or reencode the video data to fit on a single 47 GB DVD, remove various portions of the disc (such as trailers or extra audio tracks), or else split the disc onto two DVDs. Various software is available to perform these functions, and some will al...
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