DVD-R (Digital Versatile Disc-Recordable) is one of the recordable formats available on the DVD market created by Pioneer in 1997. DVD-R is a write-once format where the initial record is burned permanently into the disc and cannot be erased. A DVD-R's approximate lifespan is 100 years.
Its primary competition in the format war for dominance and support in the industry exists with DVD+R. The difference between the formats rests in the disc's individual tracking systems and speed control (ADIP for DVD+R and LPP for DVD-R). A winner between the two formats can still be debated, and some of the industry's technology has created dually-compatible accessories to accept both formats, such as hybrid drives.
The DVD-R format is supported by but not limited to: Pioneer, Fuji, Sony, Toshiba, Apple, Hitachi Samsung and TDK. A DVD-R is engineered from two bonded 0.6mm polycarbonate discs, which together add up to the 1.2mm thickness of a compact disc. A dye layer is used for recorded data.
The first of the two polycarbonate discs carries the dye layer that is topped by an alloyed silver or gold reflective layer. The other polycarbonate layer is purposed as a "dummy disc" to maintain the mechanical strength and durability of the DVD-R as a whole. The dummy disc also serves to protect the data layers from scratches and other damage.
The sandwiched polycarbonate layers also allow the drive's laser to reach the recording layer in nearly half the laser wavelength of a CD, which therefore allows the beam to write data with more accuracy than some optical storage predecessors.
The pregrooves of the DVD-R have a wobble frequency instead of perfectly spiraled pregrooves. This indicates that the groove wanders at a specific modulated frequency to guarantee precise tracking and timing at a high pit density.
There are both professional and consumer DVD-Rs in existence. A DVD-R for Authoring is for commercial content generation and this particular DVD-R needs slightly shorter laser wavelengths for precise recording and compatibility with disc authoring devices. A DVD-R for General Media is aimed at everyday consumer and home use.
These two types of DVD-R media are in place because the Authoring grade is not meant for the everyday consumer. General Media is created due to the content protection needs of CSS-encrypted entertainment titles. It is imperative for proper function that DVD-R Authoring and DVD-R General Media are recorded on their respective proper drives. However, both grades of this format can be played on DVD-ROM drives or DVD players that support playback of the DVD-R format.
DVD-Rs are backward compatible in that they function in a vast majority of existing DVD players and DVD-ROM drives, which facilitate easier archiving and at-home consumer purposes.
Be sure to check out our pages on these other DVD formats:
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