2. CHAPTER ELEVEN THE DVD FAMILY T.J.Iskandar Abd Aziz Adapted from Notes Prepared by: Noor Fardela Zainal Abidin Revised on Sept 2012 1 CGMB113/ CITB 123: MULTIMEDIA TECHNOLOGY

3. 2 222222222 Objectives At the end of this chapter, students should be able to: understand the history and evolution of digital video disc (DVD) and Blu-ray technologies define basic terms and concepts related to digital video disc (DVD) and Blu-ray technologies Describe the DVD and Blu-ray technologies and how it works

4. DVD HISTORY 3 1996: DVD Technology Introduced. Prices of Recorders and CD-R Media go down significantly. High Demands cause World-Wide CD-R Media Shortage. 1997: DVD Released. DVD Players/Movies hit consumer market. DVD-R standard created (3.9 Gig). 1998: DVD-RAM, DVD-Recordable systems/equipment hits market. DVD-Video/ROM authoring tools hits the market. CD-R prices continue to drop. 1999: DVD-Video Becomes main stream. Consumers begin purchasing DVD Players & Movies on a mass level. Most major film studios have titles on DVD. DIVX Dies (DIgital Video eXpress). Second Generation DVD Burners. 4.7 Gig DVD-R Media Developed.

5. DVD: THE BASICs 4 The first DVD player hit the market in March 1997. A DVD has a much larger data capacity. Holds about seven times more data than a CD does. Typical contents of a DVD movie:  Up to 133 minutes of high-resolution video  with 720 dots of horizontal resolution (The video compression ratio is typically 40:1 using MPEG-2 compression.)  Soundtrack presented in up to eight languages using 5.1 channel Dolby digital surround soundsurround sound  Subtitles in up to 32 languages DVD can also be used to store almost eight hours of CD-quality music per side

6. DVD Advantage 5 Better picture quality DVD movies have an on-screen index. And go to one scene to another with the remote, no need to rewind or fast-forward. DVD players are compatible with audio CDs.CDs DVD movies may have several soundtracks on them, and they may provide subtitles in different languages.

7. Storing Data in DVD 6 Like CD, data on a DVD is encoded in the form of small pits and bumps in the track of the disc. A DVD is composed of several layers of plastic, totaling about 1.2 millimeters thick. Each layer is created by injection molding polycarbonate plastic. This process forms a disc that has microscopic bumps arranged as a single, continuous and extremely long spiral track of data

8. Storing Data in DVD 7 Once the clear pieces of polycarbonate are formed, a thin reflective layer is sputtered onto the disc, covering the bumps. Aluminum is used behind the inner layers, but a semi- reflective gold layer is used for the outer layers, allowing the laser to focus through the outer and onto the inner layers. After all of the layers are made, each one is coated with lacquer, squeezed together and cured under infrared light.infrared light For single-sided discs, the label is silk-screened onto the nonreadable side. Double-sided discs are printed only on the nonreadable area near the hole in the middle (refer to picture on next slide)

9. DVD Formats 8 Cross sections of the various types of completed DVDs (not to scale)

10. Single Layer DVD has a spiral track of data. the track always circles from the inside of the disc to the outside. That the spiral track starts at the center means that a single- layer DVD can be smaller than 12 centimeters if desired. 9 Data tracks on a DVD

11. Single Sided DVD 10 The data track is incredibly tiny -- just 740 nanometers separate one track from the next (a nanometer is a billionth of a meter). And the elongated bumps that make up the track are each 320 nanometers wide, a minimum of 400 nanometers long and 120 nanometers high. (see next slide for illustration)

12. DVD Pit Layout 11

13. Single Sided DVD 12 The microscopic dimensions of the bumps make the spiral track on a DVD extremely long. If you could lift the data track off a single layer of a DVD, and stretch it out into a straight line, it would be almost 7.5 miles long To read bumps this small you need an incredibly precise disc-reading mechanism

14. DVD vs CD 13 DVDs can store more data than CDs for a few reasons:  Higher-density data storage  Less overhead, more area  Multi-layer storage

15. Double_Layer DVD 14 The technique for double-layering a DVD disc is of particular importance:  outer layer is semi-transparent [18-30% reflectivity]  inner layer is more reflective [50-80% reflectivity]  pickup lens is refocused to read desired layer  extra lead-out space required on inner layer  two methods of writing the layers  Parallel track path (PTP)  Opposite track path (OTP) - allows near continuous read

16. DVD vs CD Higher Density Data Storage  Single-sided, single-layer DVDs can store about seven times more data than CDs  A large part of this increase comes from the pits and tracks being smaller on DVDs. SpecificationCDDVD Track Pitch1600 nanometers 740 nanometers Minimum Pit Length (single-layer DVD) 830 nanometers400 nanometers Minimum Pit Length (double-layer DVD) 830 nanometers440 nanometers 15

17. DVD vs CD 16 Less Overhead, More Area  DVD format doesn't waste as much space on error correction, enabling it to store much more real information.  Another way that DVDs achieve higher capacity is by encoding data onto a slightly larger area of the disc than is done on a CD

18. DVD vs CD Multi-Layer Storage  To increase the storage capacity even more, a DVD can have up to four layers, two on each side.  The laser that reads the disc can actually focus on the second layer through the first layer. FormatCapacityApprox. Movie Time Single-sided/single-layer4.38 GB2 hours Single-sided/double-layer7.95 GB4 hours Double-sided/single-layer8.75 GB4.5 hours Double-sided/double-layer15.9 GBOver 8 hours 17

19. The DVD Player 18 A DVD player is very similar to a CD player. It has a laser assembly that shines the laser beam onto the surface of the disc to read the pattern of bumps. Considering how small the bumps are, the DVD player has to be an exceptionally precise piece of equipment.

20. The DVD Player 19 The drive consists of three fundamental components:  A drive motor to spin the disc - The drive motor is precisely controlled to rotate between 200 and 500 rpm, depending on which track is being read.motor  A laser and a lens system to focus in on the bumps and read them - The light from this laser has a smaller wavelength (640 nanometers) than the light from the laser in a CD player (780 nanometers), which allows the DVD laser to focus on the smaller DVD pits.laser  A tracking mechanism that can move the laser assembly so the laser beam can follow the spiral track - The tracking system has to be able to move the laser at micron resolutions.

21. Other DVD 20 DVD-R DVD-RW DVD-Audio

22. Blu-Ray Discs Blu-ray Discs (BD) has high storage capacity Can hold and playback large quantities of high- definition video and audio, as well as photos, data and other digital content The Blu-ray name is a combination of "blue," for the color of the laser that is used, and "ray," for optical ray. The "e" in "blue" was purposefully left off, according to the manufacturers, because an everyday word cannot be trademarked. 21 Photo courtesy Blu-ray Disc AssociationBlu-ray Disc Association

23. What is a Blu-ray Disc? 22 A current, single-sided, standard DVD can hold 4.7 GB (gigabytes) of information. That's about the size of an average two-hour, standard-definition movie with a few extra features. But a high-definition movie, which has a much clearer image takes up about five times more bandwidth and therefore requires a disc with about five times more storage.gigabytes As TV sets and movie studios make the move to high definition, consumers are going to need playback systems with a lot more storage capacity.TV sets Blu-ray is the next-generation digital video disc. It can record, store and play back high-definition video and digital audio, as well as computer data

24. What is a Blu-ray Disc? 23 Photo courtesy Blu-ray Disc Association BD-ROM disc researcherBlu-ray Disc Association

25. Blu-ray Advantages 24 Record high-definition television (HDTV) without any quality lossHDTV Provide interactivity Instantly skip to any spot on the disc Record one program while watching another on the disc Create playlists Edit or reorder programs recorded on the disc Automatically search for an empty space on the disc to avoid recording over a program Access the Web to download subtitles and other extra features

26. Blu-ray vs DVD 25 A single-layer Blu-ray disc,  can hold up to 27 GB of data  two hours of high-definition video  13 hours of standard video. A double-layer Blu-ray disc  54 GB of data,  4.5 hours of high-definition video  more than 20 hours of standard video.

27. Blu-ray vs DVD 26

28. How Does Blu-ray Work? 27 DVDs, se a red laser to read and write data. Blu-ray uses a blue laser (which is where the format gets its name). A blue laser has a shorter wavelength (405 nanometers) than a red laser (650 nanometers). The smaller beam focuses more precisely, enabling it to read information recorded in pits that are only 0.15 microns (µm) (1 micron = 10-6 meters) long -- this is more than twice as small as the pits on a DVD. Plus, Blu-ray has reduced the track pitch from 0.74 microns to 0.32 microns

29. How Does Blu-ray Work? 28 The smaller the pits (and therefore the bumps), the more precise the reading laser must be. The smaller pits, smaller beam and shorter track pitch together enable a single-layer Blu-ray disc to hold more than 25 GB of information -- about five times the amount of information that can be stored on a DVD.

30. DVD Vs Blu-Ray Construction 29 Source: Blu-ray Disc Association

31. Reference 30 OneOff Media, Inc. History of CD. 2000, 2001 Karim Nice, How DVDs Works, http://www.stuffo.com. 1998-2005 http://www.stuffo.com Stephanie Watson, How Blu-ray Works, http://www.stuffo.com. 1998-2005 http://www.stuffo.com Lachlan L. Mackinnon. Notes: Multimedia Technology (F291G2). Heriot_Watt University. Edinburgh. Scotland