Blu-ray Disc - Variants

BD9 / Mini-Blu-ray Disc

BD9 is a red laser DVD with BD contents on it. This disc should be rotated at 3x speed or more to satisfy the minimum transfer rate of 30.24 Mbit/s. These disks can be used for private storing and can be authored even without implementing AACS.^[117] BD9 was originally proposed by Warner Home Video, as a cost-effective alternative to regular Blu-ray discs.^[118] It is similar to HD DVD's 3x DVD

AVCREC

AVCREC is a standard for storing BD content on red laser DVDs using H.264/MPEG-4 AVC compression.^[119] It is similar to HD REC for HD DVD.

Blu-ray Disc recordable

Blu-ray Disc recordable refers to two optical disc formats that can be recorded with an optical disc recorder. BD-R discs can be written to once, whereas BD-RE can be erased and re-recorded multiple times. As of March 2007, BD-R/RE drives up to 4x retail are sold for about US$600 and 2x single-layer BD-R discs, with a capacity of 25 GB, can be found for around US$12. The theoretical maximum for Blu-ray Discs is about 12x as the speed of rotation (10,000 rpm) causes too much wobble for the discs to be read properly, similar to the 20x and 52x respective maximum speeds of DVDs and CDs.

HD DVD / Blu-Ray hybrid discs

Warner Bros. officially announced Total Hi Def (THD) at CES 2007. Total Hi Def (Total HD) hybrid discs supports both HD DVD and Blu-ray, HD DVD on one side (up to two layers) and Blu-ray on the other side (up to two layers). Despite initially announcing that Total HD would be ready by the second half of 2007, on June 27, 2007, Warner Bros. issued a press release stating that they would be delaying the launch of Total HD discs until early 2008. As of September 2007, no specific titles have yet been announced.

http://en.wikipedia.org/wiki/Blu-ray

Blu-ray Disc / HD DVD comparison

The primary rival to Blu-ray Disc is HD DVD. As of November 2007, HD DVD has the advantage in maximum disc capacity (51 GB triple-layer versus 50 GB dual-layer), but no titles have yet been released on the triple-layer format.^[102] It is unknown at this time whether the final specification will be compatible with current players.^[103] As of November 2007, 44% of Blu-ray titles use the 50 GB disc and 56% use the 25 GB disc^[104] while almost all HD DVD movies are in the 30 GB dual layer format.^[105]

In terms of audio/video compression, Blu-ray Disc and HD DVD are similar on the surface: both support MPEG-2, VC-1, and H.264 for video compression; and Dolby Digital, PCM, and DTS for audio compression. The first generation of Blu-ray Disc movies released used MPEG-2 (the standard currently used in DVDs, although encoded at a much higher video resolution and a much higher bit rate than those used on conventional DVDs), while initial HD DVDs releases used the VC-1 codec. Due to greater total disc capacity, the Blu-ray Disc producers may choose in the future to utilize a higher maximum video bit rate, as well as potentially higher average bit rates. As of November 2007, 41% of Blu-ray Discs are encoded in MPEG-2 while AVC is used on 33% of discs and VC-1 on 26%.^[104]

In terms of audio, there are some differences. To ensure backwards compatibility with older receivers with Dolby Digital decoders, Blu-ray Disc allows conventional Dolby Digital audiotracks at 640 kbit/s and this is the primary audio track for 33% of Blu-ray titles, while it has gone unused for HD DVD titles. The newer Dolby Digital Plus is mandatory for HD DVD players at 3 Mbit/s (and is used in 90% of HD DVD titles)^{[citation needed]}, while optional for BD players with support at a bitrate of 1.736 Mbit/s for mixes that require more than 5.1 channels (has only been used on two titles).^[106] Both formats optionally support DTS-HD High Resolution Audio, a lossy compression scheme that extends the core DTS audio for better fidelity but yet is still not lossless.

As for lossless audio, 43% Blu-ray Discs have 5.1 LPCM uncompressed audio,^[104] which is the only lossless format that is mandatory for Blu-ray players. Blu-ray Disc also has optional support for Dolby TrueHD lossless encoding of up to 8 channels of audio, and DTS-HD Master Audio, a lossless encoding of up to 8 channels of audio.^[107] As of November 2007, 7% of Blu-ray Discs are encoded in Dolby TrueHD while DTS-HD Master Audio is used on 12% on discs.^[104] In total, 60% of Blu-ray Discs have either uncompressed or lossless audio. HD DVD also supports LPCM, but unlike Blu-ray, it has mandatory support for Dolby TrueHD, although only 20% of HD DVD movies have lossless audio.^{[citation needed]}

Both HD DVD and Blu-ray Disc support the 24p (traditional movie) frame rate, but technical implementations of this mode are different between the formats. Blu-ray Disc supports 24p with its native timing, while HD DVD uses 60i timing for 24p (encoded progressively, replacing missing fields with "repeat field flags"). Decoders can ignore the “flags” to output 24p.^[108] There is no impact on picture resolution and minimal impact on storage space as a result of this, as the HD DVD format often uses the same encoded video—it simply adds notational overhead.^[clarify]

There is no Region Coding in the existing HD DVD specification, which means that titles from any country can be played in players in any other country. However, a significant percentage of Blu-ray disks have Region Coding and will only play in players sold in the corresponding geographic region.

Since both formats launched in the spring of 2006, an estimated 4.98 million high-definition discs have been sold, including 3.01 million in Blu-ray and 1.97 million in HD DVD through the end of September, 2007.^[109] However, those figures are dwarfed by the sales of regular DVDs. Combined, the two high-def disc formats accounted for only 2.5 % of overall disc sales during the first half of 2007.^[110]

http://en.wikipedia.org/wiki/Blu-ray

New Chips Enable High-Def Recording on DVDs

New recorders now can transcode an off-the-air MPEG2 signal in real time into the much-more-efficient MPEG4 AVC format. That means you can pack more video on one disc.

For the last few years most of the world's biggest consumer electronics companies have been arguing over a format for high-definiton video discs. The drama over HD DVD versus Blu-ray Disc has confused consumers and held back adoption and, it turns out, might have been unnecessary after all.

New recorders from Toshiba Corp. and Matsushita Electric Industrial Co. Ltd. (Panasonic) shown at this week's Ceatec exhibition in Japan can record high-definition TV to conventional DVDs.

Both of the new high-def formats were developed because conventional DVDs don't have the capacity to hold an HD movie in the MPEG2 format used for most of the world's HDTV broadcasting. While a DVD holds just 4.7G-bytes of data per layer, an HD DVD disc can hold 15G bytes and a Blu-ray Disc 25G bytes, enough to store a high-def movie or soccer match.

But in the last few months chips have become available that can transcode an off-the-air MPEG2 signal in real time into the much more efficient MPEG4 AVC format.

The chips have found their way into new HD DVD and Blu-ray Disc players and can increase their storage capacity by several times. For example, new machines from Sony Corp. can store about 8 hours of HDTV on a single-sided Blu-ray Disc using MPEG4 AVC -- about four times the amount of video than was possible with MPEG2.

But they also make it possible to store about 2 hours of HDTV on a conventional DVD. With hardware prices for HD DVD and Blu-ray Disc recorders typically at US$1,000 or more, some consumers may think it's better to stick with the cheap, tried and tested DVD.

Not surprisingly, that's disputed by companies pushing the new, more expensive recorders. They are offering machines that play one of the two new optical disc formats -- HD DVD or Blu-ray Disc -- as well as the "enhanced" conventional DVD.

Panasonic said the dual capability is useful because the Blu-ray Disc media is still quite expensive, so consumers will be able to choose which DVD format to use depending on their needs. "For precious recordings that they want to preserve in high-quality they can use Blu-ray Disc, and for others put them on DVD, said Manabu Sukegawa [cq], managing director of Panasonic's marketing division.

Toshiba said the 3 to 4 times capacity jump from DVD to HD DVD means much more high-def video can be stored on the new discs, and that that alone gives them merit over conventional DVDs.

While the enhanced DVD technology is being offered in new-generation machines from Toshiba, Panasonic and Sony, it remains to be seen whether they'll turn up in cheaper, DVD-only recorders. For now, Toshiba seems to be the only company contemplating this. It said it will watch market reaction and then make a decision.

Even with a fall-back to DVD there's a catch: there's no agreement on format for the "enhanced" conventional DVD, so Toshiba's HD REC and Panasonic's AVCREC formats are incompatible. HD Rec comes from the DVD Forum, the standards group responsible for DVD and the new HD DVD formats, while AVCREC comes from the Blu-ray Disc Association.

HD REC lays down a 4M bps (bits per second) MPEG4 AVC stream, while AVCREC in the Panasonic machines records at a higher 5.7M bps. That should mean a better picture but also less recording space on each DVD.

While the consumer electronics giants battled over their new formats, several smaller groups have been pushing high-def recording on DVD or formats based on the technology.

London-based New Medium Enterprises Inc. has a format called VMD (Versatile Multilayer Disc) that increases a disc capacity by adding more recording layers. A multilayer VMD disc can store about 30G bytes of information, about equivalent to HD DVD. In Taiwan, a group of companies developed FVD (Forward Versatile Disc), which added recording layers and an advanced compression system to enable high-def recording on a DVD-like disc.

However, without the support of major movie studios, all of which have a stake in Blu-ray Disc or HD DVD, the alternative formats have had trouble breaking into the mainstream market.

http://www.pcworld.com/article/id,138121-page,1/article.html

Movie Director Slams Microsoft on Supporting HD DVD

Director Michael Bay criticized Microsoft's "dirty secret" in backing HD DVD, saying the software giant's real agenda is digital downloads for movies.

Director Michael Bay criticized Microsoft's "dirty secret" in backing HD DVD saying the real agenda is to eventually move towards digital downloads.

"Microsoft wants both formats to fail so they can be heroes and make the world move to digital downloads," Bay said on his official forums, when addressing user complaints about the unavailability of Transformers on Blu-ray.

"That is the dirty secret no one is talking about. That is why Microsoft is handing out $100 million dollar checks to studios just embrace the HD DVD and not the leading, and superior Blu Ray. They want confusion in the market until they perfect the digital downloads."

Paramount and DreamWorks Animation announced in August that they would align themselves exclusively with the HD DVD high-def format.

PlayStation 3 (Blu-ray) and Xbox 360 (HD DVD with add-on) owners are both seen as key players in the high-definition disc wars given their buying power.

For more computer gaming news, visit GamePro. Story copyright © 2007 IDG Entertainment. All rights reserved.

http://www.pcworld.com/article/id,140320-page,1/article.html

High-Def Players for the Holidays

Blu-ray Disc or HD DVD? Regardless of your choice, you have lots of high-definition player options this holiday season.

1 of 11

High-Def Players for the Holidays

In the ongoing struggle for supremacy between Blu-ray Disc and HD DVD, every week seems to bring news from one camp or the other. (One week, HD DVD sells 90,000 players. Another week, Blu-ray tops the disc sales charts, again.) But that doesn't mean you need to put off your high-def player purchase. Regardless of the format you choose, you have more player options than ever before, with a slew of models new to store shelves since the summer. Players have plummeted in price this holiday season, too, dropping by as much as two-thirds over last year's prices (and one holdover from last year, Sony's Blu-ray-equipped PlayStation 3, now comes in a low-end version that's just $400).

A "next-generation" DVD player handles high-definition Blu-ray or HD DVD discs. Both formats can deliver stunning pictures filled with detail, but you should check to see which format your film favorites are on: HD DVD currently touts Paramount and Universal titles exclusively, Blu-ray has the backing of Disney, Fox, Lionsgate, MGM, and Sony, and both formats offer Warner content.

http://www.pcworld.com/article/id,140515-c,dvdplayers/article.html#