Comparison of high definition optical disc formats comparison of the formats. Blu-ray Disc and HD DVD both support the same three video compression standards: MPEG-2, VC-1 and AVC, each of which exhibits different bitrate/noise-ratio curves, visual impairments/artifacts, and encoder maturity. Initial Blu-ray Disc titles often used MPEG-2 video, which requires the highest average bitrate and thus the most space, to match the picture quality of the other two video codecs. As of July 2008 over 70% of Blu-ray Disc titles have been authored with the newer compression standards: AVC and VC-1. HD DVD titles have used VC-1 and AVC almost exclusively since the format's introduction. Warner Bros.,
The Hitchhiker's Guide to the Galaxy Tertiary to Hexagonal Phases released on 2 October 2006 in the UK. This marks the first commercial release of any BBC radio programme in a 5.1 surround mix. The disc contains as extras: the full version of the Krikket Song, a photogallery, the original online and radio trailers, the appearance of the series on Pick of the Week, and thirty minutes of behind the scenes video in five short segments. Note that while the BBC online shop is still listing the disc as a DVD-Audio disc, their own image confirms that the disc is a lower-definition standard DVD-Video. . Since the opening of the