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
CD and DVD writing speed the same 74-minute time-frame requires a higher data transfer rate. Almost all modern CD/DVD burning software supports a selection of speeds at which the writeable disc can be written. However, the option a user chooses only defines the theoretical maximum of disc burning process. There are other factors that influence the time taken for a disc to be written to: A higher writing speed results in a faster disc burn, but the optical quality may be lower (i.e. the disc is less reflective). If the reflectivity is too low for the disc to be read accurately, some parts may be