China Blue High-definition Disc China Blue High-definition Disc China Blue High-Definition (CBHD; ; alternatively "China High Definition DVD") is a high definition optical disc format announced in September 2007 by the Optical Memory National Engineering Research Center (OMNERC) of Tsinghua University in China. The format is a derivative of the HD DVD, a medium created by the DVD Forum designed to succeed regular DVDs. Although HD DVD was scrapped as a result of losing the format war to Blu-ray, CBHDs continued to be produced and marketed, though only in China. Originally called CH-DVD, CBHD is a joint venture between the DVD Forum and OMNERC.
Optical disc drive (HDD). Media technologies vary, M-DISC uses a different recording technique & media versus DVD-R and BD-R. Optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc which encodes binary data (bits) in the form of pits (binary value of 0 or off, due to lack of reflection when read) and lands (binary value of 1 or on, due to a reflection when read) on a special material (often aluminium ) on one of its flat surfaces. The encoding material sits a top a thicker substrate (usually polycarbonate) which makes up