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 | Reference Section D CD & DVD Specifications |  |
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| Reference Section D CD & DVD Specifications | |
| description | CD | DVD |
| diameter & thickness: | 120 mm (4.72") x 1.2 mm | 120 mm (4.72") x 1.2 mm |
| shortest pit (or land): | .83 microns | .4 microns |
| track pitch: | 1.6 microns | .74 microns |
| substrate layers: | 1 | 2 |
| data layers: | 1 | 1 or 2 |
| modulation: | 8-to-14 EFM | 8-to-16 EFMPlus |
| reference velocity (CLV): | 1.2 m/sec (for 1X) | 4.0 m/sec |
| reference data rate (user): | mode 1 = 153.6 KB/sec mode 2 = 176.4 KB/sec | 1,108 KB/sec (nominal) |
| laser wavelength (in air): | 780 nm (infrared) | 650 and 635 nm (red) |
| numerical (lens) aperture: | .45 | .60 |
| read-spot diameter: | .8-1.7 microns | .4 microns |
| storage capacity: | 680 MB | single-layer = 4.7 GB double-layer = 8.5 GB |
Standard Yellow Book CD-ROM | 4X High Density CD |
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| photos © 1995 DATA KINETICS | |
| Red Book: | audio CD-A |
| Yellow Book: | computer CD-ROM |
| Green Book: | Philips players CD-I (also CD-i) |
| Orange Book: | Photo CD & Write-Once CD |
| White Book: | video VCD |
| Blue Book: | CD-Plus |
Several areas remain to be resolved, including copy-protection. The 1.2 mm thickness is made up of two 0.6 mm disc substrates. For a single-layer disc, the second substrate will not contain reflective data. Earlier proposals for DVD capacities of 17 or 18.8 GB by bonding two double-layered discs back-to-back (the so-called "double sided double-layer" format) are no longer being (collectively) pursued. Much of the push for capacity was motivated by preparing the technology for full-length movies, and since 8.5 GB will provide 240 minutes of MPEG-2 video that need has been met. Note web resources at <http://www.unik.no/%7Erobert/hifi/dvd/> and also the IMA's DVD FAQ at <http://www.ima.org/forums/imf/dvd/faq.html>.
| description | Video CD | DVD Video | ||||||
| data rate: | 1.44 Mb/sec (video, audio) | 1-10 Mb/sec variable (video, audio, subtitles) | ||||||
| compression scheme: | MPEG-1 | MPEG-2 | ||||||
| subtitles: | open caption (only) | up to 32 (languages) | ||||||
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written April 1996 -- please send comments to veyr@primenet.com |  |
© ZOOM TELEVISION, INC. 1996, all rights reserved |