Optical disc authoring and modify files, without having to write the whole disc again. A compatibility technology called HighMAT allows visual material on the disc to be recognised, interpreted and supported by electronic play devices more efficiently. Optical disc authoring Optical disc authoring, including DVD and Blu-ray Disc authoring is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded ("burned") onto an optical disc (typically a compact disc or DVD). To burn an optical disc, one usually first creates an optical disc image with a full file system, of a type designed for
Optical medium Optical medium An optical medium is material through which electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. The medium has an "intrinsic impedance", given by where formula_2 and formula_3 are the electric field and magnetic field, respectively. In a region with no electrical conductivity, the expression simplifies to: For example, in free space the intrinsic impedance is called the characteristic impedance of vacuum, denoted "Z", and Waves propagate through a medium with velocity formula_6, where formula_7 is the frequency and formula_8 is the wavelength