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ow DVDs and DVD Players WorkKarim Nice

arly every movie produced today is available on DVD, and many older movies are beingoved to the DVD format. Often, a movie comes out on DVD before it comes out on videope, because the manufacturing and distribution costs for DVDs are so much lower! Bynging outstanding picture and sound to our favorite films, the DVD format is doing forovies exactly what CDs did for music. In this edition ofHow Stuff Works, you will learn what

DVD consists of, how a DVD player reads a disc and that a DVD is remarkably similar to aD -- it has just been designed to hold more data!

u may want to start with How They Work to learn how DVDs and DVD players work. If you

e thinking about buying a DVD player, be sure to look at Features to learn about all of the

atures you should keep in mind. And so on...

access all of the different parts of this article, choose from the map below:

ow They WorkDVD is very similar to a CD, but it has a much larger data

pacity. A standard DVD holds about seven times moreta than a CD does. This huge capacity means that a DVDs enough room to store a full-length, MPEG-2-encodedovie, as well as a lot of other information.

re are the typical contents of a DVD movie:

Up to 133 minutes of high-resolution video, in letterboxor pan-and-scan format, with 720 dots of horizontalresolution. The video compression ratio is typically40:1, using MPEG-2 compression.

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Soundtrack presented in up to eight languages, using5.1 channel Dolby digital surround sound.

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Subtitles in up to 32 languages.qVD can also be used to store almost eight hours ofD-quality music per side (although this is not a verymmon practice yet).

r the next section of "How They Work" Click Here, or choose from the map below:

toring Data on a DVDVDs are of the same diameter and thickness as CDs, and they are made using some of the

me materials and manufacturing methods. Like a CD, the data on a DVD is encoded in them of small pits and bumps in the track of the disc.

Howstuffworks.com's "How DVDs and DVD Players Work"

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DVD is composed of several layers of plastic, totaling about 1.2 millimeters thick. Each layercreated by injection molding polycarbonate plastic. This process forms a disc that hascroscopic bumps arranged as a single, continuous and extremely long spiral track of data.ore on the bumps later.

nce the clear pieces of polycarbonate are formed, a thin reflective layer is sputtered onto thesc, covering the bumps. Aluminum is used behind the inner layers, but a semi-reflective goldyer is used for the outer layers, allowing the laser to focus through the outer and onto thener layers. After all of the layers are made, each one is coated with lacquer, squeezedgether and cured underinfrared light. For single-sided discs, the label is silk-screened onto

e nonreadable side. Double-sided discs are printed only on the nonreadable area near thele in the middle. Cross sections of the various types of completed DVDs (not to scale) looke this:

Figure 1. Diagram of different DVD formats.

Figure 2. Each writable layer of a DVD has a spiral track of data. Onngle-layer DVDs, the track always circles from the inside of the disc to theutside. That the spiral track starts at the center means that a single-layer

DVD can be smaller than 12 centimeters if desired.

hat Figure 2 cannot impress upon you is how incredibly tiny the data track is -- just 740nometers separate one track from the next (a nanometer is a billionth of a meter). And the

ongated bumps that make up the track are each 320 nanometers wide, a minimum of 400nometers long and 120 nanometers high. Figure 3 illustrates looking through thelycarbonate layer at the bumps.


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Figure 3. Diagram of DVD pit layout.

u will often read about "pits" on a DVD instead of bumps. They appear as pits on theuminum side, but on the side that the laser reads from, they are bumps.

e microscopic dimensions of the bumps make the spiral track on a DVD extremely long. Ifu could lift the data track off a single layer of a DVD, and stretch it out into a straight line, it

uld be almost 7.5 miles long! That means that a double-sided, double-layer DVD wouldve 30 miles of data!

read bumps this small you need an incredibly precise disc-reading mechanism.


ata Storage: DVD vs. CDVDs can store more data than CDs for a few reasons:

Higher density data storageq

Less overhead, more areaq

Multi-layer storageq

gher Density Data Storagengle-sided, single-layer DVDs can store about seven times more data than CDs. A large partthis increase comes from the pits and tracks being smaller on DVDs.

pecification CD DVD

rack Pitch 1600 nanometers 740 nanometers

Minimum Pit Length

ingle-layer DVD)830 nanometers 400 nanometers

Minimum Pit Length

double-layer DVD)830 nanometers 440 nanometers

t's try to get an idea of how much more data can be stored due to the physically tighteracing of pits on a DVD. The track pitch on a DVD is 2.16 times smaller, and the minimum pitngth for a single-layer DVD is 2.08 times smaller than on a CD. By multiplying these twombers, we find that there is room for about 4.5 times as many pits on a DVD. So wherees the rest of the increase come from?

ess Overhead, More Arean a CD, there is a lot of extra information encoded on the disc to allow for error correction --s information is really just a repetition of information that is already on the disc. The errorrrection scheme that a CD uses is quite old and inefficient compared to the method used on


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VDs. The DVD format doesn't waste as much space on error correction, enabling it to storeuch more real information. Another way that DVDs achieve higher capacity is by encodingta onto a slightly larger area of the disc than is done on a CD.

ulti-Layer Storageincrease the storage capacity even more, a DVD can have up to four layers, two on eache. The laser that reads the disc can actually focus on the second layer through the first

yer. Here is a list of the capacities of different forms of DVDs:

ormat CapacityApproximate. Movie

Length

ngle Sided/Single Layer 4.38 GB 2 hours

ngle Sided/Double Layer 7.95 GB 4 hours

ouble Sided/Single Layer 8.75 GB 4.5 hours

ouble Sided/Double

ayer15.9 GB Over 8 hours

u may be wondering why the capacity of a DVD doesn't double when you add a wholecond layer to the disc. This is because when a disc is made with two layers, the pits have toa little longer, on both layers, than when a single layer is used. This helps to avoid

erference between the layers, which would cause errors when the disc is played.


he DVD Video Formaten though its storage capacity is huge, the uncompressed video data of a full-length movieuld never fit on a DVD. In order to fit a movie on a DVD, you need video compression. A

oup called the Moving Picture Experts Group (MPEG) establishes the standards for

mpressing moving pictures.

hen movies are put onto DVDs, they are encoded in MPEG-2 format and then stored on thesc. This compression format is a widely accepted international standard. Your DVD playerntains an MPEG-2 decoder, which can uncompress this data as quickly as you can watch it.

he MPEG-2 Format and Data Size Reductionmovie is usually filmed at a rate of 24 frames per second. This means that every second,ere are 24 complete images displayed on the movie screen. American and Japaneseevision use a format called NTSC, which displays a total of 30 frames per second; but ites this in a sequence of 60 fields, each of which contains alternating lines of the picture.her countries use PAL format, which displays at 50 fields per second, but at a highersolution (see How Video Formatting Works for details on these formats). Because of the

ferences in frame rate and resolution, an MPEG movie needs to be formatted for either theTSC or the PAL system.

e MPEG encoder that creates the compressed movie file analyzes each frame and decidesw to encode it. The compression uses some of the same technology as still image

mpression does to eliminate redundant or irrelevant data. It also uses information from othermes to reduce the overall size of the file. Each frame can be encoded in one of three ways:

As an intraframe, which contains the complete image data for that frame. This methodof encoding provides the least compression.

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As a predicted frame, which contains just enough information to tell the DVD player howto display the frame based on the most recently displayed intraframe or predicted frame.This means that the frame contains only the data that relates to how the picture haschanged from the previous frame.

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As a bidirectional frame. In order to display this type of frame, the player must have theinformation from the surrounding intraframe or predicted frames. Using data from theclosest surrounding frames, it uses interpolation, something like averaging, to calculate

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the position and color of each pixel.

pending on the type of scene being converted, the encoder will decide which types ofmes to use. If a newscast were being converted, a lot more predicted frames could be used,cause most of the scene is unaltered from one frame to the next. On the other hand, if ary fast action scene were being converted, in which things changed very quickly from oneme to the next, more intraframes would have to be encoded. The newscast would compressa much smaller size than the action sequence.

all of this sounds complicated, then you are starting to get a feeling for how much work yourVD player does to decode an MPEG-2 movie. A lot of processing power is required; even

me computers with DVD players can't keep up with the processing required to play a DVDovie.


VD AudioVD audio and DVD video are different formats. DVD audio discs and players are pretty rareht now, but they will become more common, and the difference in sound quality should beticeable. In order to take advantage of higher quality DVD audio discs, you will need a DVD

ayer with a 192kHz/24-bit digital to analog converter. Most DVD players have only akHz/24-bit digital to analog converter. So if you want to be able to listen to DVD audio discs,sure to look for a DVD audio player with a 192kHz/24-bit digital to analog converter

AC).

VD audio recordings can provide far better sound quality than CDs. The chart below lists thempling rate and accuracy for CD recordings and the maximum sampling rate and accuracyDVD recordings. CDs can hold 74 minutes of music. DVD audio discs can hold 74 minutes

music at their highest quality level, 192kHz/24-bit audio. By lowering either the samplinge or the accuracy, DVDs can be made to hold more music. A DVD audio disc can store uptwo hours of 6 channel, better than CD quality, 96kHz/24-bit music. Lower the specificationsther, and a DVD audio disc can hold almost 7 hours of CD quality audio.

pecification CD Audio DVD Audio

ampling Rate 44.1 kHz 192 kHz

amples Per Second 44,100 192,000

ampling Accuracy 16-bit 24-bit

umber of Possible Output Levels 65,536 16,777,216

an audio CD or DVD, each bit represents a digital command telling the DAC what voltagevel to output (see How Digital Recording Works for details). While an ideal recording would

ow the raw waveform exactly, digital recordings sample the sound at different frequencies,d therefore lose some of the data.


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Comparison of a raw audio signal to the CD audio and DVD audio output.

e graph above shows how the highest quality DVD audio compares to CD audio. You cane that DVD follows the signal more closely, but it's still a long way from perfect.


he Player ItselfDVD player is very similar to a CD player. It has a laser assembly that shines the laser beamto the surface of the disc to read the pattern of bumps (see How CDs Work for details). The

VD player decodes the MPEG-2 encoded movie, turning it into a standard composite videonal (see How Television Works for details). The player also decodes the audio stream and

nds it to a Dolby decoder, where it is amplified and sent to the speakers.

eading a DVDe DVD player has the job of finding and reading the data stored as bumps on the DVD.nsidering how small the bumps are, the DVD player has to be an exceptionally precise

ece of equipment. 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.

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A laser and a lens system to focus in on the bumps and read them. The light from thislaser has a smaller wavelength (640 nanometers) than the light from the laser in a CDplayer (780 nanometers), which allows the DVD laser to focus on the smaller DVD pits.

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A tracking mechanism that can move the laser assembly so that the laser's beam canfollow the spiral track. The tracking system has to be able to move the laser at micronresolutions.

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side the DVD player, there is a good bit of computer technology involved in forming the datao understandable data blocks, and sending them either to the DAC, in the case of audio oreo data, or directly to another component in digital format, in the case of digital video orta.

e fundamental job of the DVD player is to focus the laser on the track of bumps. The lasern focus either on the semi-transparent reflective material behind the closest layer, or, in these of a double-layer disc, through this layer and onto the reflective material behind the inneryer. The laser beam passes through the polycarbonate layer, bounces off the reflective layerhind it and hits an opto-electronic device, which detects changes in light. The bumps reflectht differently than the "lands," the flat areas of the disc, and the opto-electronic sensortects that change in reflectivity. The electronics in the drive interpret the changes in

lectivity in order to read the bits that make up the bytes.

e hardest part of reading a DVD is keeping the laser beam centered on the data track. Thisntering is the job of the tracking system. As the DVD is played, the tracking system has toove the laser continually outward. As the laser moves outward from the center of the disc,


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e bumps move past the laser at an increasing speed. This happens because the linear, orngential, speed of the bumps is equal to the radius times the speed at which the disc isvolving. So, as the laser moves outward, the spindle motor must slow the spinning of theVD so that the bumps travel past the laser at a constant speed, and the data comes off thesc at a constant rate.

interesting thing to note is that if a DVD has a second layer, the start of that layer's datack can be at the outside of the disc instead of the inside. This allows the player to transitionickly from one layer to the next, without a delay in data output, because it doesn't have toove the laser back to the center of the disc to read the next layer.


What They DoVD players can change the way you watch movies and listen to music at home. They

prove the quality of the picture and the sound, and they are more versatile thaneocassette recorders. Here are some of the things that you can do with a DVD player:

Watch High Quality Movies with Good SoundYou probably know that a DVD player will let you watch DVD movies. These movieshave some advantages overvideocassette movies. The picture quality is better, and

many of them have Dolby Digital orDTS sound, which is much closer to the sound you

experience in a movie theater.

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Skip to your Favorite Parts of MoviesMany DVD movies have an on-screen index, where the creator of the DVD has labeledmany of the significant parts of the movie, sometimes with a picture. With your remote, ifyou select the part of the movie you want to view, the DVD player will take you right tothat part, with no need to rewind or fast-forward.

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Play Audio CDsDVD players are compatible with audio CDs, so if you want to get rid of your CD player

to make room for a DVD player, go ahead.

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Watch Movies in Different Picture FormatsSome DVD movies have both the letterbox format, which fits wide-screen TVs, and the

standard TV size format, so you can choose which way you want to watch the movie.

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Watch Movies with Subtitles or in a Different LanguageDVD movies may have several soundtracks on them, and they may provide subtitles indifferent languages. Foreign movies may give you the choice between the versiondubbed into your language, or the original soundtrack with subtitles in your language.

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eaturesupported Formats

DVD MoviesJust about all players play DVD movies.

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Music CDs

Most players also play music CDs.

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Video CDsSome players can handle this format, which is used mostly for music videos and somemovies from foreign countries.

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CD-RsSome players can play content that you create on your own computer.

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Audio DVDsA few players can handle this upcoming format for high quality audio.

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ther FeaturesDolby Digital Decoderq


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This feature allows the DVD player to decode the Dolby Digital information from a DVD

and convert it to six separate analog channels. This feature is not necessary if you havea Dolby Digital receiver, which has a digital input that carries all of the audio information.

DTS DecoderThis feature allows the DVD player to decode the DTS information from a DVD and

convert it to six separate analog channels. Again, this feature is not necessary if youhave a receiver with a DTS decoder.

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DTS CompatibleAll DVD players are DTS compatible. They pass the digital audio information on to thereceiver, which then decodes it.

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Simulated SurroundIf you are going to hook the DVD player up to a TV or a stereo system with only twospeakers, a DVD player with simulated surround processing will give you some sense ofsurround sound without the extra speakers.

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Disc CapacitySome DVD players can hold three, five or even several hundred discs. Since most DVDplayers can also play audio CDs, if you buy a player with a disc high capacity you couldstore your whole CD collection in the machine.

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96kHz/24-bit DACThis is the speed and accuracy of the digital to analog converter (DAC), which convertsthe audio information into an analog signal. Most movie soundtracks are encoded in this

format, so this is really a required feature, and most DVD players will have at least a96kHz/24-bit DAC.

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192kHz/24-bit DACThis is an upcoming format for audio-only DVDs that are recorded at speeds of up to192kHz and 24-bits. Only the newest DVD audio players have the 192kHz/24-bit DACrequired to play these audio discs.

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Remote Control TypeDVD players may come with three types of remotes:

A dedicated remote, which only runs the DVD player.q

A multibrand remote, which can control other components, like VCRs and TVsmade by other manufacturers. Usually they only support the more commonbrands.

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A learning remote, which can learn the signals from other remotes and assignthem to a button. This feature is useful if you have uncommon brands ofcomponents to control.

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deo OutputsComponent Video OutputsThese outputs provide the highest quality video signal to yourTV. They are quite rare

right now; only the newest high-end TVs can support them. But, if you have such a TV,you'll definitely want a DVD player with component video outputs.

There are three separate connectors for component video output. The player picturedbelow has one component video output.

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DVD Player video outputs from left to right: Composite video, S-Video,Component Video.

S-Video OutputsTVs with this type of connection are more common. S-video provides a very good picturequality, and every DVD player has at least one of these outputs. The player picturedabove has two of them.

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Composite Video Outputs

These are the most common type of output, and they provide adequate picture quality.Usually they have a yellow plastic insert. The player pictured above has two of theseoutputs.

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udio OutputsCoaxial Digital Output and Optical Digital OutputThese outputs provide the highest quality audio. They send the digital sound informationto the receiver for decoding. You can use either one of these if you have a Dolby Digitalreceiver.

DVD Player audio outputs.

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5.1 Channel Outputs5.1 channel is a set of six analog outputs, one for each of the Dolby Digital channels (left

front, center front, right front, left rear, right rear and subwoofer). The DVD playerdecodes the Dolby Digital signal and uses its own DAC to output an analog signal.These are the outputs you'll need to use if you are hooking the DVD player up to a"Dolby Digital ready" receiver.

DVD players with 5.1 channel outputs will always have Dolby Digital decoders, and theymay or may not have DTS decoders. If you have a "Dolby Digital ready" receiver andyou want DTS sound, you will need a DVD player with a built-in DTS decoder.

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Stereo OutputsThese outputs carry only the stereo music signal. You would use these if you werehooking your DVD player up to a TV that has only two speakers.

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When You Shope've created a DVD Feature Comparison chart for you to use as you research variousodels. Take it to the store with you and fill in the blanks for each model you are interested in.u may also want to keep an additional copy near your desk as you research various modelsthe Internet.

e feature comparison chart is available to you as a PDF. You will need the freeAdobe

robat Readerto view it.

Download the comparison chart!q

u can also check out DVD players available in the HSW store!

ny DVP-CX850D - 200-disc DVD/CD changer

ny DVP-FX1 - Portable DVD/CD player with 7" LCD screen

ny DVP-S360 - DVD/CD player

nasonic DVD-LV55 - Portable DVD/CD player with 5" LCD screen

ny DVP-C660 - 5-disc carousel DVD/CD changer


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C XV-M565/567 - 3-disc DVD/CD changer

t all players can play DVD audio discs. Here are some DVD audio players that can:

Panasonic DVD-A7q

Technics DVD-A10Nq

ook Out!ere are a few things you should be aware of when buying a DVD player:

Is it compatible with your home theater system?If you want to be able to get the full experience of the Dolby Digital sound used on many

DVDs, you will need a home theater system with five speakers, a subwoofer, and areceiver that is either "Dolby Digital ready" or has a built-in Dolby Digital decoder.Assuming you have all that...

If your receiver is "Dolby Digital ready," then it does not have a Dolby Digital decoder, soyou need to buy a DVD player with its own Dolby Digital decoder and 5.1 channel

outputs. If you also want your system to be compatible with DTS sound, then your DVDplayer will need a DTS decoder, too.

If your receiver has its own Dolby Digital decoder and DTS decoder, then you don't needa DVD player with 5.1 channel outputs, and you can save some money on cables byusing the digital outputs.

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Do you want to play DVD audio discs?This is an emerging standard for higher quality audio recordings. There are very fewplayers that support this format; so if you want to be able to play these discs, be verycareful to choose a player designed forDVD audio.

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Is it compatible with your TV?There are several different types of video connections available. Unless you have a very

old TV that only takes a coaxial cable, you should have no trouble hooking your DVDplayer up to your TV. If you have a very new, high-end TV with component video inputs,make sure your DVD player has this type of output, because it is not that common rightnow.

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Where to Buy800.COMq

Amazonq

buy.comq


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J&R Music Worldq

Mercataq

MobShop.comq

StoreSearch!q

uBidq

ManufacturersHitachiq

JVCq

Kenwoodq

Onkyoq

Panasonicq

Philipsq

Pioneerq

RCAq

Samsungq

Sharpq

Sonyq

Toshibaq

AQWhat does "DVD" stand for?DVD stands for digital versatile disc, but some sources declare that it doesn't stand for

anything anymore.

q

How much do DVD players and DVDs cost?

Prices of DVD players range from about $200 to $2,000. The discs have come down inprice since the start of 2000, ranging now from about $14 to $30.

q

We have a VCR and a collection of movies on tape. Why would we want a DVDplayer?A DVD player has several advantages over a VCR:

The quality of the picture and sound on a DVD is better than on a videotape, and

DVDs maintain their high quality over time.

q

With a DVD player, you can jump right to a certain part of the movie, withoutrewinding and fast-forwarding, so you can easily watch a favorite scene again andagain if you want to.

q

Movies on DVD can be seen in wide-screen (letterbox) format, bringing you closer

to the experience of watching the movie in the theater, or in TV format, which fillsthe screen of most television sets.

q

DVDs often have interesting extras, such as a director's commentary or castbiographies.

q

q

Can I record television shows or movies on a DVD player?DVD players are not yet designed to record from the analog television signal. But youcan record data on DVDs with yourcomputer.

q

Can I play CDs on a DVD player?Yes. DVD players are completely compatible with audio compact discs. And music will

become increasingly available in DVD format. See this page for more discussion of the

DVD audio format.

q


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What is the difference between DVDs and laser discs?Laser disc is an older technology. It offered a better picture and better sound thanvideotapes, and it is comparable to DVD. But the laser disc format is analog; DVDs aredigital (see How Analog and Digital Recording Works). Laser discs are only used for

prerecorded movies, and they are larger, about 12 inches in diameter, instead the 5-inchdiameter of DVDs. The two formats usually can't be played on the same machine. Laserdiscs, like DVDs, allow viewers to go to the exact scene they wish to see, and to freezea frame or slow the picture. Laser discs can only hold an hour on each side, so you haveto flip the disc to watch the second half of the movie. Because of DVD compressiontechniques, DVDs can hold more data. You rarely have to flip a DVD to watch a whole

movie. Laser disc players are noisier than DVD players, and they can sometimes suffer"laser rot" -- the aluminum side of the disc oxidizes, and the quality of the discdeteriorates. DVDs are less likely to have this problem, because manufacturingtechniques have improved. As the popularity of DVD grows, laser discs are becomingharder to find.

q

Are there a lot of movie and music titles available on DVD?There are thousands of movies available on DVD now, and more are being added asDVD players become more common. In 2000, most movie studios released their moviesin both VHS and DVD format. Older movies, such as Disney animation classics, are alsoshowing up on DVD. You can rent DVDs at almost any video store these days.

q

What are region codes?Movie studios use region codes on DVDs to thwart unauthorized copying, and to control

the release dates of DVD movies. The actual region code is stored in one byte on theDVD. The DVD player or drive has a region code in its firmware. Personal computerDVD-ROM players often have the code in the software or in the MPEG-2 decoder. Forthe player or drive to play the movie, the two codes must match. The code is also printedon the back of a DVD package, superimposed on a small image of the globe. If you havea DVD that was made for release in Asia, you won't be able to play it on a DVD playerintended for use in Australia.

q

onnecting the DVD Playernnecting a DVD player to your stereo receiver (or television, if you don't have a receiver)

volves making two basic connections: audio and video.

udioe first connection to make is for the audio portion of the signal. There will be several optionspending on the receiver you have.

The best choice (if available) is either to use an optical (also called Tos-link) orcoaxial(RCA) digital connection. These two choices are equal in quality. In order to use either ofthese, you will need to have both an output on the DVD player, and an input on thereceiver. Only receivers with built-in Dolby Digital decoders will have this type of input.

The audio outputs on a DVD player.

q

If your receiver does not have a built-in Dolby Digital orDTS decoder, but is "Dolby

Digital ready," look for the 5.1-channel Dolby or5.1-channel DTS. This connectioninvolves six cables, corresponding to different speaker channels: left front, center front,right front, left rear, right rear and subwoofer.

q


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The last option to connect the two components is with analog RCA outputs. This is atwo-cable connection, with one cable delivering the left speaker sound, and the othercable delivering the right. This connection will deliver only stereo sound, but it may beyour only option if you are hooking up directly to a television, or if you have an old

receiver with only two channels.

q

deoe second connection is for the video portion of the DVD player.

The best quality choice is to use component connection. This connection consists ofthree cables: color-labeled red, blue and green. The quality is superb. However, these

connections only exist on extremely high-end receivers and television sets.

The video outputs on a DVD player.

q

The next option is s-video. One cable connects the DVD player to the receiver in thissetup.

q

The last option, similar to the audio setup, is to use the analog RCA video output,usually color-labeled yellow on both ends. This will deliver the lowest quality, but willsuffice for most older, analog televisions.

q

ool FactsThe first DVD playerhit the market in March 1997.q

About 10 million DVD players have been sold since March 1997.q

There are almost 8,000 different DVD titles available in the United States.q

If an average DVD movie were uncompressed, it would take at least a year to downloadit over a normal phone line.

q

The new Sony PlayStation 2, scheduled for release Oct. 26, 2000, will be the first video

game system able to play DVDs.

q

DVDs often have special features hidden on the disc. These "Easter eggs" can bepreviews of other movies, computersoftware or music. DVD Review has a listing of

some great Easter eggs that viewers have found on DVDs.

q

Some DVDs carry commentary tracks, in which the filmmaker talks about the moviewhile it is running. This can be very exciting for true film buffs. DVDs can also containextra, previously unreleased scenes. And a DVD is sometimes a director's cut -- thefilm as the director originally intended it.

q

Because DVDs are so durable, film aficionados can watch a favorite movie repeatedlywithout the disc losing its quality. This is also good for parents whose children like towatch the same movies over and over again.

q

You can use the "jog-and-shuttle" feature on DVD players to find scenes, play them inslow motion or freeze a scene, and the video quality will remain the same.

q


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Software loaded from DVD, as opposed to CD-ROM, can contain more information. An

entire encyclopedia can fit onto one DVD, whereas other formats would require multiplediscs.

q

ooksDVD Demystified: The Guidebook for DVD-Video and DVD-ROM, by Jim Taylor. ISBN:

0070648417

q

CD-R/DVD: Digital Recording to Optical Media, by Lee Purcell. ISBN: 0071357157q

DVD Player Fundamentals, by Andrew Yoder. ISBN: 0790611945q

Home Theatre for Everyone: A Practical Guide to Today's Home Entertainment

Systems, by Robert Harley, Tomlinson Holman. ISBN: 0964084929

q

Doug Pratt's DVD-Video Guide, by Doug Pratt. ISBN: 0966974441q

VideoHound's DVD Guide, by Mike Mayo. ISBN: 1578591155q

"Why DVD?: A Meat and Potatoes Guide for the Uninitiated," by Joseph Matheny. (notavailable through Amazon)

q

nd Coming Soon...DVD Demystified, 2nd Edition, by Jim Taylor, will be published Dec. 2000*. ISBN:

0071350268

q

DVD Production, by Mark Ely, will be published Jan. 2000*. ISBN: 0240516117

*Amazon does take pre-orders.

q

nksZDNet: How to Buy DVD Playersq

ZDNet: DVD Player Shootoutq

DVD FAQq

DVD Center: DVD Hardware Player Informationq

DVD Player Comparison Chart - Basic Featuresq

DVD Player Hardware Reviewsq

AudioREVIEW.com - Product Reviews - DVDq

DVD Player Decision Guideq

bout the Authorrim Nice is senior editor for automotive and mechanical technology for How Stuff Works.


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