Optical disc the DataPlay format, can have capacity comparable to that of the larger, standard compact 12 cm disc. Third-generation optical discs are in development, meant for distributing high-definition video and support greater data storage capacities, accomplished with short-wavelength visible-light lasers and greater numerical apertures. Blu-ray Disc and HD DVD uses blue-violet lasers and focusing optics of greater aperture, for use with discs with smaller pits and lands, thereby greater data storage capacity per layer. In practice, the effective multimedia presentation capacity is improved with enhanced video data compression codecs such as H.264/MPEG-4 AVC and VC-1. The following formats go beyond the
DVD-R DL DVD-R DL DVD-R DL (DL stands for Dual Layer), also called DVD-R9, is a derivative of the DVD-R format standard. DVD-R DL discs hold 8.5 GB by utilizing two recordable dye layers, each capable of storing a little less than the 4.7 gigabyte (GB) of a single layer disc, almost doubling the total disc capacity. Discs can be read in many DVD devices (older units are less compatible) and can only be written using DVD-R DL compatible recorders. It is part of optical disc recording technologies for digital recording to optical disc. DVD-R DL has compatibility issues with legacy DVD-ROM