THOSE WHO DONT HAVE ANY IDEA ABOUT BLURAY
Blu-ray Disc is an optical disc storage medium designed to supersede the standard DVD format. Its main uses are for storing high-definition video, PlayStation 3 video games, and other data, with up to 25 GB per single layered, and 50 GB per dual layered disc. Although these numbers represent the standard storage for Blu-Ray drives, the specification is open-ended, with the upper theoretical storage limit left unclear. 200 GB discs are available, and 100 GB discs are readable without extra equipment or modified firmware. The disc has the same physical dimensions as standard DVDs and CDs.
The name Blu-ray Disc derives from the blue-violet laser used to read the disc. While a standard DVD uses a 650 nanometer red laser, Blu-ray uses a shorter wavelength, a 405 nm blue-violet laser, and allows for almost ten times more data storage than a DVD.
During the format war over high-definition optical discs, Blu-ray competed with the HD DVD format. Toshiba, the main company supporting HD DVD, conceded in February 2008, and the format war ended. In late 2009, Toshiba released its own Blu-ray Disc player.
Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2009, more than 1,500 Blu-ray Disc titles are available in Australia and the United Kingdom, with 2,500 in Japan, the United States and Canada.
Competition from HD DVD
The DVD Forum, chaired by Toshiba, was deeply split over whether to develop the more expensive blue laser technology or not. In March 2002, the forum voted to approve a proposal endorsed by Warner Bros. and other motion picture studios that involved compressing HD content onto dual-layer standard DVD-9 discs.In spite of this decision, however, the DVD Forum's Steering Committee announced in April that it was pursuing its own blue-laser high-definition solution. In August, Toshiba and NEC announced their competing standard, Advanced Optical Disc. It was finally adopted by the DVD Forum and renamed HD DVD the next year, after being voted down twice by DVD Forum members who were also Blu-ray Disc Association members—prompting the U.S. Department of Justice to make preliminary investigations into the situation.
HD DVD had a head start in the high definition video market, as Blu-ray Disc sales were slow to gain market share. The first Blu-ray Disc player was perceived as expensive and "buggy", and there were few titles available. This changed when the PlayStation 3 was launched, since every PS3 unit also functioned as a Blu-ray Disc player. At CES 2007, Warner proposed Total Hi Def—a hybrid disc containing Blu-ray on one side and HD DVD on the other—but it was never released. By January 2007, Blu-ray Discs had outsold HD DVDs, and during the first three quarters of 2007, BD outsold HD DVDs by about two to one. In a June 28, 2007 press release, Twentieth Century Fox cited Blu-ray Disc's adoption of the BD+ anticopying system as a key factor in their decision to support the Blu-ray Disc format. In February 2008, Toshiba withdrew its support for the HD DVD format, leaving Blu-ray as the victor.
Some analysts believe that Sony's PlayStation 3 video game console played an important role in the format war, believing that it acted as a catalyst for Blu-ray Disc, as the PlayStation 3 used a Blu-ray Disc drive as its primary information storage medium. They also credited Sony's more thorough and influential marketing campaign.
Technical specifications
Type Physical size Single layer capacity Dual layer capacity
Standard disc size 12 cm 25 GB / 23866 MiB / 25025314816 B 50 GB / 47732 MiB / 50050629632 B
Mini disc size 8 cm 7.8 GB / 7430 MiB / 7791181824 B 15.6 GB / 14860 MiB / 15582363648 B
High-definition video may be stored on Blu-ray ROM discs with up to 1920×1080 pixel resolution at up to 59.94 fields per second, corresponding to 29.97 frames per second interlaced or 24 frames per second progressive. Alternatively, progressive scan at 1280x720 pixel resolution can go up to 59.94 frames per second:
Resolution Frame rate1 Aspect ratio Video format restrictions
1920×1080 59.94-i 16:9
1920×1080 50-i 16:9
1920×1080 24-p 16:9
1920×1080 23.976-p 16:9
1440×1080 59.94-i 16:9 (anamorphic) MPEG-4 AVC / SMPTE VC-1 only
1440×1080 50-i 16:9 (anamorphic) MPEG-4 AVC / SMPTE VC-1 only
1440×1080 24-p 16:9 (anamorphic) MPEG-4 AVC / SMPTE VC-1 only
1440×1080 23.976-p 16:9 (anamorphic) MPEG-4 AVC / SMPTE VC-1 only
1280×720 59.94-p 16:9
1280×720 50-p 16:9
1280×720 24-p 16:9
1280×720 23.976-p 16:9
720×480 59.94-i 4:3/16:9 (anamorphic)
720×576 50-i 4:3/16:9 (anamorphic)
