 First two layers of Blu-ray have a 25 GB capacity, but the triple layer disc adds a further 50 GB making 100 GB total.The fourth layer adds a further 28 GB.b All HD DVD players are required to decode the two primary channels (left and right) of any Dolby TrueHD track; however, every Toshiba made stand-alone HD DVD player released thus far decodes 5.1 channels of TrueHD.