Nowadays, optical discs are having a great impact on storage as it can hold up for over fifty gigabytes of data. In optical-disc technology, laser beam alters the surface of a metallic disk to present a data. Usually, the disc is read by an optical disc drive using a laser that projects a tiny beam of light. Compact disc,known as CD is one of the most widely used optical formats. Others types of optical disc is digital versatile disc,DVD. While CDs and DVDs are the most widely used optical discs, there are still lack of using them like insufficient for recording high-definition video,and others. As a result, the next generation of optical disc is build on. The current is Blu-ray Disc (BD) that is the topic that i wanna discuss here..:)
Blu-ray (not Blue-ray) also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. This extra capacity combined with the use of advanced video and audio codecs will offer consumers an unprecedented HD experience.
Blu-ray products can easily be made backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc even though it's the same size as a CD/DVD. This together with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to hold 25GB/50GB.
edited from:
http://www.blu-ray.com/info/
Question & Answer session with Mr.Ramueldo...:)
| Q: Blu-ray,what it is? |
| Ramueldo: "Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format. The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc."
| Q: Why the name is Blu-ray? | | Ramueldo: "The name Blu-ray is derived from the underlying technology, which utilizes a blue-violet laser to read and write data. The name is a combination of "Blue" (blue-violet laser) and "Ray" (optical ray). According to the Blu-ray Disc Association the spelling of "Blu-ray" is not a mistake, the character "e" was intentionally left out so the term could be registered as a trademark.The correct full name is Blu-ray Disc, not Blu-ray Disk (incorrect spelling)
The correct shortened name is Blu-ray, not Blu-Ray (incorrect capitalization) or Blue-ray (incorrect spelling)
The correct abbreviation is BD, not BR or BRD (wrong abbreviation)."
Q: How much data can you fit on a Blu-ray disc?Ramueldo: "A single-layer disc can hold 25GB. A dual-layer disc can hold 50GB.
-To ensure that the Blu-ray Disc format is easily extendable (future-proof) it also includes support for multi-layer discs, which should allow the storage capacity to be increased to 100GB-200GB (25GB per layer) in the future simply by adding more layers to the discs."
| Q: How much video can you fit on a Blu-ray disc? | | Ramueldo: "Over 9 hours of high-definition (HD) video on a 50GB disc n about 23 hours of standard-definition (SD) video on a 50GB disc."
| Q: How fast can you read/write data on a Blu-ray disc? | | Ramueldo: "According to the Blu-ray Disc specification, 1x speed is defined as 36Mbps. However, as BD-ROM movies will require a 54Mbps data transfer rate the minimum speed we're expecting to see is 2x (72Mbps). Blu-ray also has the potential for much higher speeds, as a result of the larger numerical aperture (NA) adopted by Blu-ray Disc. The large NA value effectively means that Blu-ray will require less recording power and lower disc rotation speed than DVD and HD-DVD to achieve the same data transfer rate. While the media itself limited the recording speed in the past, the only limiting factor for Blu-ray is the capacity of the hardware. If we assume a maximum disc rotation speed of 10,000 RPM, then 12x at the outer diameter should be possible (about 400Mbps). This is why the Blu-ray Disc Association (BDA) already has plans to raise the speed to 8x (288Mbps) or more in the future."
Q: What video codecs will Blu-ray support?Ramueldo: "MPEG-2 - enhanced for HD, also used for playback of DVDs and HDTV recordings.
MPEG-4 AVC - part of the MPEG-4 standard also known as H.264 (High Profile and Main Profile).
SMPTE VC-1 - standard based on Microsoft's Windows Media Video (WMV) technology."
| Q: What audio codecs will Blu-ray support? | | Ramueldo: "Linear PCM (LPCM) - up to 8 channels of uncompressed audio. (mandatory)
Dolby Digital (DD) - format used for DVDs, 5.1-channel surround sound. (mandatory)
Dolby Digital Plus (DD+) - extension of Dolby Digital, 7.1-channel surround sound. (optional)
Dolby TrueHD - lossless encoding of up to 8 channels of audio. (optional)
DTS Digital Surround - format used for DVDs, 5.1-channel surround sound. (mandatory)
DTS-HD High Resolution Audio - extension of DTS, 7.1-channel surround sound. (optional)
DTS-HD Master Audio - lossless encoding of up to 8 channels of audio. (optional)"
Q: Will Blu-ray replace DVDs? Ramueldo: "Yes, that's the expectation. The Blu-ray format has received broad support from the major movie studios as a successor to today's DVD format. In fact, seven of the eight major movie studios (Disney, Fox, Warner, Paramount, Sony, Lionsgate and MGM) have released titles in the Blu-ray format. Many studios have also announced that they will begin releasing new feature films on Blu-ray Disc day-and-date with DVD, as well as a continuous slate of catalog titles every month.However, the two formats (Blu-ray and DVD) will most likely co-exist for quite some time until HDTVs become more widespread."
|
|
|
|
|
Blue-ray Discedited from: http://www.blu-ray.com/faq/
In a nut shell, in this modern and sophisticated world today, there are many new technologies were created day by day. As we can see here, Blu-ray disc is created as a next generation of optical disc to replace the insufficient of CDs and DVDs. Every weakness of technologies in the past was replaced by others new technologies better and better. Maybe after 30 and 40 years in the future, people are not burden of work anymore as the technologies will help us to do our work better. Personally,blue-ray disc gives me satisfication in watching movies or playing games!(PS3..hehehe..:)..
0 comments