How is DVD+R/+RW related to competing formats like DVD-R/-RW/-RAM?
What is the DVD Forum?
Will there double sided discs?
Will there be dual-layer discs?
Do DVD+R/+RW PC drives and DVD+R/+RW video recorders need different discs?
How many times can a DVD+RW disc be overwritten?
Do DVD+RW discs need to be finalized?
Do DVD+R discs need to be finalized?


How is DVD+R/+RW related to competing formats like DVD-R/-RW/-RAM?
DVD+R/+RW, DVD-RAM and DVD-R/-RW are all rewritable DVD formats, however, only DVD+R/+RW is designed from the start to be compatible with existing DVD-ROM drives and DVD-Video players, both on a physical as well as on a logical level. This means that a DVD+R or DVD+RW disc recorded in a DVD+R/+RW video recorder can be played in virtually all DVD-Video players or DVD-ROM equiped PCs, and that any DVD+R or DVD+RW disc recorded with data on a PC DVD+R/+RW drive can be read by most DVD-ROM drives.

DVD-RAM uses a totally different kind of physical recording method, which is absolutely incompatible with DVD (hence, it can hardly be called 'DVD'). No normal DVD player will be able to read DVD-RAM discs, even if you use the newer DVD-RAM version without a cartridge housing.

DVD-R and DVD-RW were initially not designed to be used as a DVD-compatible recording solution. DVD compatibility was added at a later point, however since the formats were not developped for this purpose, they do not offer the level of compatibility and flexibility (while remaining DVD compatible!) that DVD+R/+RW offers. Furthermore, DVD-R/-RW is less suitable for data applications as well due to a number of technical limitations (such as the inability of random access writing). For a very extensive comparison of the various formats, please refer to Comparison with DVD-R/-RW Video Recorders and Comparison with DVD-R/-RW PC Drives.

The DVD-RAM and DVD-R/-RW supporters have announced numurous compatibility programs for their DVD players (such as "DVD-Multi" and "VR support"), however only a small minority of players will include these (costly!) additions. DVD-RAM/-R/-RW lies the burden of compatibility on the player, while DVD+R/+RW lies the burden of compatibility on the recorder itself.


What is the DVD+RW Alliance?
The DVD+RW Alliance is a group of companies that promote the DVD+RW standard. Initially, it consisted of the companies that co-developped the standard: Philips, Hewlett-Packard, Sony, Yamaha, Ricoh, Mitsubishi/Verbatim, Thomson/RCA and Dell. To date, the DVD+RW Alliance consists of dozens of other companies from various fields, such as PC hardware manufacturers (like Fujitsu-Siemens), PC drive manufacturers (like AOpen, BenQ and NEC), disc manufacturers (like Maxell, TDK, Fuji and Ritek), software publishers (like Roxio, Sonic and Ahead) and numurous other companies. Over-all, DVD+RW has the broadest support in the IT industry of all recordable DVD formats.


What is the DVD Forum?
The DVD Forum is a group of companies that initially co-developped the DVD-Video and DVD-ROM formats. Later-on, the Forum also developed other formats (like the recordable DVD formats DVD-R/-RW/-RAM and the DVD-Audio format), but by then most companies had decided not to support these new DVD Forum formats but instead opt for a better solution (like the DVD+R/+RW format for recordable DVD, or the Super Audio CD format for high-resolution audio applications). The DVD Forum is not a standards-setting body, but instead just a trade-organization promoting some standards. It has no power in deciding what format should be used in DVD products. Ironically, the DVD+R/+RW format is more faithfull to the official DVD Forum-developped DVD-Video specification than the DVD-R/-RW/-RAM formats developed by the Forum itself!


Will there double sided discs?
Yes, the DVD+R/+RW standard allows for double sided DVD+R/+RW discs. It is doubtfull that these discs will become very popular however, since they are likely to cost more than 2 single-sided discs, and they are much harder to handle or to identify (as there is no room on the disc surface to write down its contents).


Will there be dual-layer discs?
In October 2003, Philips and the DVD+RW Alliance announced specifications for dual-layer DVD+R discs. This is sometimes also called DVD+R9, refering to the "DVD9" naming used for pre-recorded dual-layer DVDs. The capacity of a dual-layer disc will be 8.5 GB. First products supporting this new disc format, both PC data drives and consumer DVD video recorders, are expected to appear onto the market during 2004.

Like DVD+RW and the existing single-layer DVD+R, DVD+R9 was designed to be fully compatible with existing DVD-Video players and DVD-ROM drives. In that respect, a recorded DVD+R9 disc should behave identical to a pre-recorded dual-layer DVD when used in read-only equipment.

We expect DVD+R9 to become particularly popular in PC applications, as it allows for almost double the amount of data to be recorded (think of harddisk backups or large media files like DivX movies or MP3s). Furthermore, it should be easier to use a DVD+R9 disc for backups of dual layer DVDs, which make up for the majority of DVD movie releases. It is expected that the same copy protection mechanisms that exist today for DVD+R and DVD+RW will be applied to DVD+R9.

We personally expect DVD+R9 to become less important in consumer DVD video recorders, as we think that rewritability is an important requirement for most people when looking for a VCR replacement. Dual-layer recording capability is only available for write-once DVD+R discs. However, future consumer recorders might support DVD+R9 as well, enabling users to get longer recording times per disc.

All future DVD+R9 drives and recorders will also record on DVD+RW and standard single-layer DVD+R media. Single-layer DVD+R media will remain to be available, as it suits a lot of recording purposes, and they are likely to be cheaper to manufacture. Current DVD+R/+RW drives and recorders cannot record onto DVD+R9 media, however, since DVD+R9 is fully compatible with the DVD-ROM specifications, they will be able to read those discs recorded on other equipment.


Do DVD+R/+RW PC drives and DVD+R/+RW video recorders need different discs?
No, all discs will be compatible with both data drives and DVD+RW video recorders. However, it will be possible for manufacturers to create media that is "optimized" for video or data applications. Data media will generally be cheaper than video media. However, there is no technical difference between the two. Note that although DVD+R and DVD+RW discs might be labeled as "4.7 GB", or "240 minutes of video", this does not mean that their usage is limited to either video or data applications.


How many times can a DVD+RW disc be overwritten?
A DVD+RW disc is very similar to a CD-RW disc in terms of the number of times that it can be re-written to. Tests have proven a re-recording capability of over 1,000 times, so this is why this number is stated by most manufacturers as a minimum. However, in practice this number will probably be much higher.


Do DVD+RW discs need to be finalized?
No. Everytime a DVD+RW disc is ejected, either from a DVD+R/+RW drive in a PC or from a DVD+R/+RW video recorder, it automatically contains the needed information for the disc to be read in a normal DVD-Video player or DVD-ROM drive. There's no need to perform a time-consuming "finalisation" process on the disc, as is required for all other rewritable DVD formats, and for CD-RW. Likewise, there is no such thing as "unfinalizing" a DVD+RW disc: you can always make modifications or add new contents to a disc without performing some special procedure in advance.


Do DVD+R discs need to be finalized?
Yes. In order for a DVD+R disc to be read in a DVD-Video player or on a computer's DVD-ROM drive, it needs to be "finalized". When the disc is finalized, its final Table Of Contents will be written on the location of the disc where a normal DVD player will look for it, and you can no longer add new material to it. Finalization can be done on a DVD+R/+RW video recorder by applying the "Finalization" option on the recorder's on screen menus (see manual). On a PC that uses some form of packet-writing software, you need to select some "close" or "finalize" option from the program's menu to make the disc compatible. When you write a full disc using a DVD authoring package or a copy tool, finalization is usually automatically applied. Note that finalization is not required for reading the disc in a DVD+R/+RW video recorder or a DVD+R/+RW drive. You can add new video segments or data at various time intervals as long as the disc is not finalized. Be aware of the fact that finalization does not exist for DVD+RW: a DVD+RW disc is always immediately DVD compatible.