DVD Formats an d Media

DVD disks vary in capacity, application, and storage format. It is important to know what is available before you choose a DVD writer

Saturday, October 11, 2003

Unlike CDs, the DVD market is still in a nascent stage with tons of different formats floating around. There are formats for the physical DVD disc itself, formats for DVD applications, and finally formats for the way data is actually written on them. So until one or two formats standardized, one should know what is currently available. 

Physical formats
By physical formats, we mean the physical characteristics of DVD discs. There are four types of physical DVD discs formats:

DVD-5: DVD-5 is a single-sided, single-layered DVD with 4.7 GB storage capability.
DVD-9: DVD-9 is also single-sided but dual-layered disc with 8.5 GB storage capability.
DVD-10: DVD-10 is a double-sided, single-layered DVD with 9.4 GB storage capability.
DVD-18: DVD-18 is a double-sided, double-layered DVD with 17 GB storage capability.

Application formats
While physical format describes the media on which the data is stored, application formats describe what kind of data - software, video, or music, is stored and how. These include DVD-Video, DVD-Audio and of course plain data. 

DVD-Audio: DVD Audio provides higher quality audio storage than what is available for CDs. It provides Dolby Digital AC-3, 5.1 channel surround sound.

DVD-Video: DVD has the capability to produce near-studio-quality video using high-quality MPEG-2 video compression.

High quality video combined with surround-sound audio can give a true home theatre experience. In addition, the DVD format defines a way to have multiple languages in movies along with subtitles, which again can be in multiple languages. The present DVD-video players available commercially may or may not play DVD-Audio.

Data DVDs: A DVD disc can also be used for storing ordinary data from a computer, such as your documents, applications, etc.

DVD writable formats
The physical application formats tell the physical characteristics of a disc and the type of data stored on it. The writable formats define the different ways data is written to and read from the DVD disc, be it audio, video or computer data. There are several formats in this category:

DVD-ROM: DVD-ROM discs are similar to CD-ROM discs, but store data at a much higher density, giving greater capacity than CD-ROM. Like CD-ROM, they store computer files and can only be read and not written to. DVD-ROM can be read in DVD video players and computer DVD drives.

DVD-RAM: DVD-RAM discs are like a virtual hard disc with random read-write access. They can be re-written on more than 100,000 times. They can be used as normal hard disc drives using drag and drop. DVD-RAM discs can only be used in DVD-RAM drives and not in DVD-Video players or other DVD drives. They are available in sizes 2.6, 4.7, 5.2 and 9.4 GB.

DVD-R: It is equivalent to DVD-ROM but can also be recorded on, though only once. They are available in capacities of 4.7 and 9.4 GB and can be read in DVD players and drives on computers. DVD-R discs are available in two versions DVD-R(A), for professional authoring and DVD-R(G) for general consumers. The major difference between the two is that the professional supports Mastering and Copy protection.

DVD-RW: Developed by Pioneer, it is a re-write version of the write-once DVD-R format and can be written up to 1,000 times. It can record on single-sided 4.7GB discs. This format is readable in most modern DVD players and drives but may not be compatible with many older players and drives. 

DVD+RW: Like DVD-RW, it is a different re-writable version of DVD-R format and is fully compatible with all DVD players and drives. It can also be written up to 1,000 times and is designed to be more suitable for both real-time video recording and random data recording. They are available in sizes of 4.7GB. Hewlett-Packard, Mitsubishi-Chemical/Verbatim, Philips, Ricoh, Sony, Yamaha and Thomson Multimedia support this format, making it a more widely accepted format.

DVD+R: DVD+R is based on the DVD+RW format but can be written to only once. They possess all qualities of the DVD+RW format and are available in sizes of 4.7GB. Both DVD+R/+RW are the best formats available and may soon replace all other formats.

Finally a word about writing to DVD discs. To write to a certain format DVD disc, you need to have a compatible DVD writer/recorder. This means that to write to a DVD+RW disc you need a DVD+RW recorder only, a DVD-RW or DVD-R or DVD+R recorder won’t do. It may let you read DVD+RW discs but will not allow you to write to them. These days, most recorders support multiple formats, so you can have a single recorder for all formats. Prices of course vary depending upon the number of formats supported by a recorder. 

Anoop Mangla

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