DVD-HD vs. Blu-ray

Another media war is in full swing, and just like the VHS vs. Beta war, there will likely be only one winner, and the best technology will not necessarily win. The competing technologies vying for standard acceptance as the next generation DVD format are: Blu-ray [PDF] -- backed by Sony, Panasonic, Philips, HP, Dell, Hitachi, Matsushita, LG, Mitsubishi, Pioneer, Samsung, Sharp, TDK and Thomson; and, DVD-HD (also known as Advanced Optical Disc - AOD) -- backed by Toshiba and NEC. Both technologies offer increased picture clarity, anti-piracy protection, along with the HD format. The new formats both offer increased storage capacity and transfer rates. Blu-ray's capacity is at 27GB single layer, while DVD-HD is at 20GB -- both promising transfer rates of 36Mbps, which is way over the 11Mbps offered by today's DVDs. Why the need for additional storage? (Other than just bigger is better, that is?) HD standard. A 2 hour recording using the HDTV standard requires about 27GB of storage, using the standard MPEG-2 compression used in today's DVDs. (DVD-HD solicited Microsoft to help it develop a compression algorithm that would fit a typical 2 hour HDTV recording on their 20GB discs.) But the applications are far more reaching than just HDTV -- which Hollywood hasn't really jumped into whole heartedly anyway. There are the data applications -- think of it -- a 50-cent disc being able to store 27GB of data -- and at transfer rates of 36Mbps ... enough to bring every geek out of the basement (and I don't even have a basement!). Both Blu-ray and DVD-HD achieve their higher capacity by increasing the density of pits used to encode data on the disc's recording track. Increasing the pit density was achieved by lowering the wavelength of the laser used to encode them from 650nm (red) to 405nm (blue), and in the case of Blu-ray, increasing the numerical aperature of the laser's objective lens from 0.60 to 0.85 -- DVD-HD uses the same objective lens as today's DVD, of 0.60, and has the added advantage in that it can be manufactured using the same plants making today's DVDs.