DVDs and DVD Players - The Basics

Answers to Basic Questions About DVD and DVD Players

Setting a DVD on a DVD Player Disc Loading Tray
Inserting DVD into DVD Player. mage © Robert Silva - Licensed to About.com

Even in the age of smartphones and internet streaming, DVD has the distinction of being the most successful home entertainment product in history. When it was introduced in 1997, it didn't take long for it to become the main source of video entertainment in most homes - in fact, even today, a large number of consumers have two, or maybe more, devices in their homes than can play DVDs.

On the other hand, how much do you really know about your DVD player - specifically, what it can and cannot do.

For a closer look at the DVD format, here some facts about players and discs that you might find very interesting.

What The Letters "DVD" Actually Stand For

DVD stands for Digital Versatile Disc. DVDs can be used for storing video, audio, still image, or computer data. Many people refer to DVD as a Digital Video Disc, however, technically, this is not correct.

What Makes DVD Different Than VHS

DVD differs from VHS in the following ways:

  • Audio and video information on VHS tape is imbedded on a magnetic imprint that has been recorded on video tape and is physically read by a rotating head in a VCR. Video and audio information on a DVD is imbedded in physically stamped pits that are read optically by a laser.
  • Ironically, a DVD physically has more in common with the traditional vinyl record than video tape. Audio signals on a vinyl record are imprinted in physical grooves, which are physically read by a stylus. The difference, besides the groove vs pits disc construction, is that the signal on a vinyl record is an analog waveform and the signal on a DVD are digital bits.
  • DVD can support both standard 4x3 and anamorphic widescreen 16x9 screen aspect ratios.
  • DVD is capable of providing twice the video resolution than VHS, making for a much more detailed image and better color consistency.
  • You can access any part of the DVD in a random or very fast manner, whereas you have to fast forward or rewind a VHS tape to find a specific location on the tape.
  • DVD is capable of interactive menu access and added features, such as multiple language tracks, audio commentaries, and additional features not capable on the VHS format. DVD also supports Closed Captioning and On/Off Subtitling in several languages.
  • In addition DVD supports synchronized multiple camera angle viewing, provided the filmmaker supplies the alternate camera angle footage shot during the filming process to the DVD production staff (this feature is rarely utilized).
  • DVDs are not affected by magnetic fields. Commercial DVDs cannot be erased.

DVD Region Coding

Region coding is a controversial system enforced by the MPAA (Motion Picture Association Of America) that controls the distribution of DVDs in World Markets based on feature film release dates and other factors.

The World is divided into several DVD regions. DVD players can only play DVDs that are coded for a specific region.

However, there are DVD players available that can bypass the Region Code system, which some exceptions. This type of DVD player is referred to as a Code Free DVD player.

For a full explanation on DVD Region Codes, Regions, and Resources for Code Free DVD Players, refer to my article: Region Codes - DVD's Dirty Secret.

Accessing The Audio On A DVD

One of the advantages of DVD is the ability of a DVD to hold several audio options simultaneously.

Although audio on a DVD is digital, you can access the audio in either an analog or digital form. DVD players have standard stereo analog audio outputs that can be connected to any stereo system or stereo TV with stereo audio inputs. DVD players also have digital audio outputs that can be connected to any AV receiver with digital audio inputs. You must use either digital optical or digital coaxial audio connections to access Dolby Digital or DTS 5.1 surround sound audio.

For full information on surround sound formats, check out my article Surround Sound Basics.

DVD Player Video Connections

Most DVD players have standard RCA composite video, S-video, and Component Video outputs.

On most DVD players, the component video outputs can be set to transfer either a standard interlaced video signal or a progressive scan video signal to a television. Most DVD players also have DVI or HDMI outputs for better connection to HDTVs as well. DVD players typically do not have cable or antenna outputs.

For a visual look at DVD Player Connections, check out a DVD Player Rear Panel Photo

Connecting A DVD player To a TV That Only Has An Antenna Or Cable Connection

The popularity of DVD has created a minor "glitch". The DVD player is a high performance unit designed to be used in a variety of setups. It has a plentiful variety of video output (composite, S-video, Component) and audio output (analog, digital optical, and digital coaxial) capabilities. However, there is one thing manufacturers didn't account for: the increasing demand for players to be able to connect to a standard cable or antenna input on older analog TVs.

To connect a DVD player to a TV that only has an antenna input connection, you need a device referred to as an RF Modulator.

The RF modulator is placed between the DVD player and the TV.

For detailed illustrated step-by-step instructions for connecting an RF modulator, TV, and DVD player together, refer to Set up and Use an RF Modulator with a DVD Player and a Television

Movie DVDs vs DVDs Made On A DVD Recorder Or PC

DVD movies that you buy or rent have different characteristics than DVDs you make at home on your PC or DVD recorder.

DVD Recording formats for consumer use are similar to the format used in commercial DVDs you buy at the local video store, which is referred to as DVD-Video. However, the way video is recorded on the DVD is different.

Both homemade and commercial DVDs utilize "pits" and "bumps" that are physically created (the pits on the unreadable side, and the bumps are on the readable side) on the discs to store the video and audio information, but there is a difference on how the "pits" and "bumps" are created on commercial DVDs vs home recorded DVDs.

Pre-recorded DVD movies are manufactured with a stamping process. This process is sort of like the way vinyl records are made - although the technology is obviously different (vinyl records are stamped with grooves versus DVD being stamped with pits and bumps).

On the other hand, DVDs you make at home on a DVD recorder or a PC are "burned".

For more details on this, refer to my article: The Difference Between Commercial DVDs and DVDs You Make With a DVD Recorder or PC

DVD Players and Progressive Scan

Standard video, such as from VHS VCRS, Camcorders, and SD TV broadcasts, is displayed on  CRT TV as a result of scanning series of lines on a screen surface in a format called interlaced scan. Interlace Scan are lines of video displayed in an alternate fashion on a TV screen. All the odd lines are scanned first, then all the even lines. These are referred to as fields.

This process results in an interlaced image. Each frame on your screen is made up of the two interlaced fields of video. Although video frames are displayed every 30th of a second, the viewer, at any given point in time is only seeing half the image. Since the scanning process is so quick, the viewer's brain perceives the video image on the screen as a complete image.

Progressive Scan vs Interlaced Scan

Progressive scan differs from interlaced scan in that the image is displayed on a screen by scanning each line (or row of pixels) in a sequential order rather than an alternate order, as is done with interlaced scan. In other words, in progressive scan, the image lines (or pixel rows) are scanned in numerical order (1,2,3) down the screen from top to bottom, instead of in an alternate order (lines or rows 1,3,5, etc... followed by lines or rows 2,4,6).

By progressively scanning the image onto a screen every 60th of a second rather than "interlacing" alternate lines every 30th of a second, a smoother, more detailed, image can be produced on the screen that is perfectly suited for viewing fine details, such as text, and is also less susceptible to interlace flicker.

How To Access Progressive Scan

In order to access a DVD player's progressive scan feature, you must also have a TV that has progressive scan display capability, such as all LCD, Plasma, OLED TVs, and LCD and DLP video projectors. However, since a DVD player's progressive scan feature can be turned off or on, you can still use a progressive scan DVD capable DVD player on a non-progressive scan capable TV (such as an older CRT set).

For a more detailed discussion on progressive scan and how it relates to your own DVD viewing, check out my article: Progressive Scan - What You Need To Know.

How DVD Players Are Able To Play CDs

CDs and DVDs, although sharing some basic similarities, such as the size of the discs, and the the fact that they are both digitally encoded formats in which video, audio, and/or still image information are imprinted via either physical pits (commercial) or burned (home recorded) - they are also different.

Due to the differences in the size of the pits or burned surface of DVDs and CDs, they require the reading laser to send a light beam of different wavelengths to read the information on each type of disc.

To accomplish this, a DVD player is equipped with one of two things: A laser that has the ability change its focusing accurately based on DVD or CD detection or, more commonly, a DVD player will have two lasers, one for reading DVDs and one for reading CDs. This is often referred to a Twin-Laser Assembly as is usually listed in the spec sheet for DVD players that have them.

The other reason that DVD players can also play CDs is not so much technical, but is a conscious marketing strategy. When DVD was first introduced to the market in 1996-1997, it was decided that one of the best ways to increase sales of DVD players and make them more appealing to consumers was to also include the ability for DVD players to also be able to play CDs. As a result, the DVD player actually became two units in one, a DVD player and a CD player.

Which is Better For Playing CDs - A DVD Player or a CD-only Player?

Although some audio processing circuitry is shared, the basic requirements of both CD and DVD compatibility are accommodated separately within the same chassis.

Now, as to whether ALL DVD players are better CD players, not all are. You have to compare them unit-by-unit. However, a great many DVD players are actually very good CD players, especially those players than can also play SACD and DVD-Audio disc. This is due their higher-end audio processing circuitry. Also, as a result of the popularity of DVD and CD, it is becoming harder to find CD-only players. In fact, most CD-only players available these days are either mid or high-end high-end single tray units, along with a few Carousel-type players. CD and DVD Jukebox players were once plentiful, but have since fallen by the wayside.

Superbit DVDs

Superbit DVDs are DVDs that use all the space for the just the movie and the soundtrack - no extras such as commentaries or other special features are included on the same disc. The reason for this is that the Superbit process uses the entire bit-rate (thus the name Superbit) capability of a DVD disc, thus maximizing the quality of the DVD format. As a result, the colors have more depth and variation and there is less edge artifact and video noise issues. Think of it as an "enhanced DVD".

However, although Superbit DVDs provide an improvement in image quality over standard DVDs, they are still not as good as a Blu-ray or HD-DVD disc. Superbit DVDs are still 480i resolution. On the the other hand, if you have a progressive scan DVD player you can output a Superbit DVD in 480p and you can also do upscaling up to 1080p when played on an upscaling DVD player.

Superbit DVDs are playable on all DVD and Blu-ray Disc players. However, since the introduction of Blu-ray, Superbit DVDs are no longer being released.

For more details on Superbit DVD, refer to the following article: A Look at Superbit (DVD Talk). Also, check out a list of all Superbit DVD titles that were released (note that the Now Available link is no longer active) as well as a very good visual comparison between Standard DVD and Superbit DVD.

DualDisc

DualDisc is a controversial format that is a disc with a DVD layer on one side and a CD-type layer on the other. Since the disc has a slightly different thickness than either a standard DVD or standard CD, it may not have complete playback compatibility on some DVD players. DualDiscs are not officially recognized as meeting CD specifications. As a result, Philips, developers of the CD and holders of most CD patents, do not authorize the use of the official CD label on DualDiscs.

For more information on DualDisc, check out the DualDisc Website. For information on compatibility issues of DualDisc with your own DVD player, contact tech support or the webpage of the manufacturer of your DVD player

Blu-ray/DVD Flipper Discs

Another "Dual" type of disc is the Blu-ray/DVD flipper Disc. This type of type of disc is a Blu-ray on one side, and a DVD on the other. Both the Blu-ray and DVD sides can be played on a Blu-ray Disc player, but only the DVD side can be played on a DVD player. There are very few movies available on Blu-ray flipper Disc.

HD-DVD/DVD Combo Discs

Similar to a Blu-ray flipper disc, an HD-DVD/DVD combo disc is an HD-DVD on one side, and a DVD on the other. Both the HD-DVD and DVD sides can be played on an HD-DVD player, but only the DVD side can be played on a DVD player. There are about 100 HD-DVD combo disc titles - However, since the HD-DVD format was discontinued in 2008, such discs are very difficult to find.

Universal DVD Players

A Universal DVD player refers to a DVD player that plays SACDs (Super Audio CD) and DVD-Audio Discs as well as standard DVDs.

SACD and DVD-Audio are high-resolution audio formats that were intended to replace the standard music CD, but have not made a large market impact with consumers. Universal DVD players have a set of 6-channel analog audio outputs that allow the consumer to access SACD and DVD-Audio on an AV receiver that also a set 6-channel analog audio inputs.

Due to differences in the way SACD and DVD-Audio signals are encoded on a disc, the DVD player must convert the signal to an analog form as digital optical and digital coaxial connections on a DVD player that are used for access of Dolby Digital and DTS audio are not compatible with SACD or DVD-Audio signals.

On the other hand, SACD and DVD-Audio signals can be transferred via HDMI, but that option is not available on all players. Also, in the case of SACD signals, in order to be transferred via HDMI, is commonly converted to PCM.

Upscaling DVD Players

An Upscaling DVD player is a unit that is equipped with either a DVI (Digital Visual Interface) or HDMI (High Definition Multi-media Interface) connection. This connection can transfer the video signal from the DVD player to an HDTV that has the same type of video connections in pure digital form, as well as provide "upscaling capability".

A standard DVD player, without upscaling, can output video resolution at 720x480 (480i). A progressive scan DVD player, without upscaling, can output 720x480 (480p - progressive scan) video signals.

Upscaling is a process that mathematically matches the pixel count of the output of the DVD signal to the physical pixel count on an HDTV, which is typically 1280x720 (720p), 1920x1080 (1080i or 1080p.

Visually, there is very little difference to the eye of the average consumer between 720p or 1080i. However, 720p can deliver a slightly smoother-looking image, due to the fact that lines and pixels are displayed in a consecutive pattern, rather than in an alternate pattern.

The upscaling process does a good job of matching the upscaled pixel output of a DVD player to the native pixel display resolution of an HDTV capable television, resulting in better detail and color consistency.

However, upscaling cannot convert standard DVD images into true high-definition images. In fact, although upscaling works well with fixed pixel displays, such as Plasma, LCD, and OLED TVs, results are not always consistent on older CRT-based high definition TVs.

Any DVD player can be hooked up to an HDTV. Although Upscaling DVD players are better able to match the native pixel resolution of an HDTV, you will still get good results on a standard DVD player that is connected via an HDTV's provided Component or S-Video inputs.

However, if you DO have an HDTV, and a standard DVD player, you will get the best results using the Component video (red-blue-green) connection between the DVD player and the HDTV. In addition, if your DVD player is progressive scan capable, always use that option when connected to a progressive scan capable television.

More Details On Video Upscaling

Best Upscaling DVD Players

Beyond DVD - Blu-ray Disc

With the advent of HDTV, more DVD players are equipped with "upscaling" capability to better match the performance of the DVD player with the capabilities of the today's HDTV's. However, DVD is not a high definition format.

For many consumers, the introduction of Blu-ray has confused the issue regarding the difference between the upscaling of standard DVD and the true high definition capability of Blu-ray.

Upscaled DVD tends to look a little flatter and softer than Blu-ray. Also, when looking at color, especially reds and blues, it is also easy to tell the difference in most cases, as even with upscaled DVD, reds and blues have a tendency to override detail that may be underneath, while the same colors in Blu-ray are very tight and you still see the detail under the color.

Beyond Blu-ray - Ultra HD Blu-ray

In addition to DVD and Blu-ray Disc, the solidification 4K Ultra HD TV in the marketplace has resulted in the introduction Of the Ultra HD Blu-ray Disc format, which not only takes Blu-ray image quality up a notch, but far supercedes the video quality of DVD. For more details on Ultra HD Blu-ray Disc players, refer to my article: Before You Buy an Ultra HD Blu-ray Player.

More Info

Keep in mind, as with all consumer electronics technology, that things are constantly changing. In other words, information in the above are dynamic and will be updated when needed.

Also, for topics specifically related to DVD recording, be sure to also check out my DVD Recorder FAQs

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