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.,
Optical disc recording modes the data, and closed by a lead-out area. The data is addressable in sectors of 2048 bytes each, with the first sector address being zero. There are no run-out blocks as in DVD-R disc-at-once. Session-At-Once (SAO) recording allows multiple sessions to be recorded and finalized on a single disc. The resulting disc can be read by computer drives, but sessions after the first are generally not readable by CD Audio equipment. Audio Master Quality Recording was introduced by Yamaha in 2002. This recording mode significantly reduces jitter levels causing noise and clicks (-30% according to Yamaha) and improves audio and