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DVD Formats Explained

The various formats that DVDs are available in, ie DVD+R, DVD-R, DVD-RAM, DVD+RW, DVD-RW, can be quite confusing to a novice, so there follows a brief and, hopefully, easy to understand explanation below.

DVD, standing for either Digital Versatile Disc or Digital Video disc, is a replacement technology for Video Cassettes. Just as video cassettes were originally available in 2 formats - VHS and Betamax - writeable DVDs are available in different formats. Different manufacturers support different formats and you need to ensure that you use the correct format for compatibility.

• DVD-R, DVD-RW
  DVD-R is a write once DVD format. Once data is written to the disk, it becomes permanent.
  DVD-RW is the rerecordable version of this format. Data written to a DVD-RW can be erased and rerecorded.
  This format is normally supported by standard DVD players and recorders.
• DVD+R, DVD+RW
  DVD+R is a write once DVD format. Once data is written to the disk, it becomes permanent.
  DVD+RW is the rerecordable version of this format. Data written to a DVD+RW can be erased and rerecorded.
  This format is normally supported by standard DVD players and recorders.
• DVD-RAM
  DVD-RAM is a rerecordable format but is only compatible with devices that support this format (fewer than DVD+/-R) and is usually used in devices that have cartridges such as camcorders.
• Dual Layer
  Dual layer technology is a relatively recent innovation that allows you to write ("burn") twice as much data onto a DVD. A standard writeable DVD has a maximum capacity of 4.7GB or 120 mins of high quality video. Dual layer DVDs (DVD+R DL and DVD-R DL) can currently hold 7.95 GB.
  Expect further rapid advances in dual layer technology, with discs able to hold ever increasing amounts of data in the near future.
• DVD-ROM
  DVD-ROM is the standard format used by manufactured video and games. These discs should play on all DVD players / recorders.

DVD Writers
Many dvd writers will write either DVD-R or DVD+R discs, or both DVD-R and DVD+R formats, but they usually play both formats.

Notes About Compatibility
Even if you follow all the rules of compatibility, you will find that certain discs, even though supposedly compatible with your device, will not play on it. This is true no matter how much you have paid for your dvd player / recorder and is reminiscent of a few years ago when certain hifi equipment had difficulty reading cd-r discs. This is more a problem connected with the brand of writeable disc that you are using, than the format. Different brands use different dyes on the discs, and some devices have difficulty reading certain dyes.

There are no hard and fast ways around this, but if you find a brand that works well with the all devices you wish to use it on, then stick with it. My personal favourite is for the RiDisc DVD-R which uses the G05 dye, which (to date) has worked with every device I have tried.

DIVX / XVID

Some DVD players will play files in the DIVX or XVid formats, which are compressed video formats.

• Click here for information about video compression.
• Click here for Divx compatible DVD players