Recordable DVD Primer
Picking your way through the ton of information available on recordabel, or DVD can be a nightmare. To help you out, we’ve done our best to distill it into this summary.
There are five recordable versions of DVD; DVD-R for General, DVD-R for Authoring, DVD-RAM, DVD-RW, and DVD+RW. None of the formats is fully compatible with the other although there are drives which will read,a nd in some cases write to more than one format.
DVD-R for General and DVD-R for Authoring are essentially DVD versions of CD-R. And DVD-RW is a DVD version of CD-RW. All three formats can be read in standard DVD-ROM drives and in most DVD video players. The difference between DVD-R for General and DVD-R for Authoring is that DVD-R for General is a format intended for widespread consumer use and doeasn’t support ‘professional’ features such as piracy protection or duplication in mass duplicators. The Pioneer DVD-RW drive which is the most popular PC device for writing to DVD uses the DVD for General format. And as as the case with CD, DVD-RW is essentially the same as DVD_R except that it can be erased and written to again and again.
DVD-RAM is slightly different as it is a sector based disc which mounts on the desktop of a PC when inserted into a drive. Files can then be copied to it in the same way as any other mounted media. Some single-sided DVD-RAM discs can be removed from their caddy and inserted in a DVD-ROM drive which will then be able to read the content of the disc. There are DVD video recorders which use the DVD-RAM format. This enables themn to pull off clever tricks like time shifting – where you can watch the beginning of a programme you have recorded while you are still recording the end on the same disc.
DVD+RW is the newest format and not supported by the DVD Forum (link), the body which sets the standards for DVD. However, it is supported by some of the biggest electronics and computer manufacturers, and is therefore likely to stick around. It is also the format used by Philips in its DVD video recorders (link). Despite not being authorised by the DVD Forum, DVD+RW is claimed by its supporterd to be compatible with more DVD video players than DVD-R and DVD+RW writers are found in PCS from quite a few manufacturers.