At this time there are now several kinds of optical discs that can be used for DVD or CD duplication based on what the disc is to be used for. Each of these works on the basis of different the reflectivity of the recorded area, although new technological innovation working with other techniques are currently being created. The most generally used kind of optical disc currently used in CD duplication uses an organic dye that is burned by a laser light to modify its reflective properties. These kinds of optical discs are recorded to as a whole and can simply be used once. Re-writable optical discs use what is known as change phase alloys. All these have an area which is changed between crystalline and amorphous states, which have different reflective qualities, again with a use of a laser. Although this kind of disc provides greater versatility to the user for DVD and CD duplication, the distinction between the different reflectivity is not as great as for the colour surface discs, and therefore different drives are required to read the different discs, although the majority of the present day drives supports both types.
Throughout the CD duplication process, a number of tasks are needed to be examined before the duplication. The appropriate power of the laser needed for the burning session needs to be adjusted, which is done by the OPC or Optimal Power Calibration. The recording option also needs to be placed. An optical disc can be recorded during the duplication process in four methods: Track at once, which is generally used for sound CDs as the tracks are authored one by one with spaces in between. Disc at once, which writes the whole disc in one go. Session at once, which writes and finishes several sessions on one CD, and packet writing only to part of the disc as wanted.
The connectivity of the DVD or CD duplication recording machine must be congruent, and as an outcome most use common connectivity choices. The most frequently used is the Parallel ATA connections for internal drives, while exterior drives connect a PATA drive mechanism to connect inside the case. Also, DVD recorders are use SATA or Serial ATA connections which can be used in very high velocity drives. Stand alone drives are more likely to use standard AV connectors.
Currently there is some difference from the typical recording process during CD duplication that are mandatory required and therefore included in the recording process. Pause is needed for recording from some reasons, a pause must be placed as the recorder usually works without one. The recorder executing the duplication will place a ‘buffer’ to transfer the other recorded files. When the information in this buffer processed by the recorder is faster than a computer application it will load up again. To fix this, buffer under-run safety is now generally placed into recorders to fix this problem. ‘Over burning’ is also a standard add-on to the features of recorders used in DVD and CD duplication. It allows recording onto a CD beyond its standard limits. It also provides an error margin on discs to improve tolerance for the audio CD’s read head.