HD DVD BD9 formats. HD Rec is an extension of the HD DVD format for recording HD content on regular red laser DVD-Rs/DVD-RWs using H.264/MPEG-4 AVC compression. It was approved by the DVD Forum on September 12, 2007 It is comparable to Blu-ray Disc's AVCREC. The China Blue High-definition Disc (CBHD), a high-definition optical disc format, was based upon the HD DVD format. Like the HD DVD, CBHD discs have a capacity of 15 GB single-layer and 30 GB dual-layer and can use existing DVD production lines. Unlike the HD DVD format, industry support for this format has grown steadily. HD DVD
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