DVDs and DVD Players - The Basics

All 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 Lifewire

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 that can play DVDs.

However, how much do you really know about your DVD player and what it can and cannot do? Check out some facts.

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:

  • For VHS, audio and video information are embedded on a magnetic imprint recorded on videotape, which is read by a rotating head in a VCR. For DVD, video and audio information is embedded in pits that are read optically by a laser.
  • Ironically, a DVD physically has more in common with the traditional vinyl record than videotape. 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 supports 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. However, although DVD provides higher resolution than VHS, it is not a true high definition format - more on this in the "Upscaling DVD Players" section of this article.
  • 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 supports interactive menus and added features, such as multiple language tracks, audio commentaries, and additional features not available in the VHS format. DVD also supports Closed Captioning and On/Off Subtitling in several languages.
  • 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. This type of DVD player is referred to as a Code Free DVD player.

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

Accessing The Audio On A DVD

One of the advantages of DVD is its ability to offer several audio options on a disc.

Although audio on a DVD is digital, it can be accessed 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.

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 transfer either a standard interlaced video signal or a progressive scan video signal to a TV (more on that later in this article). Most DVD players also have DVI or HDMI outputs for better connection to HDTVs. DVD players typically don't have antenna/cable outputs.

Using A DVD Player with a TV That Only has an Antenna/Cable Connection

One thing manufacturers didn't account for: a demand for players to be able to connect to a standard antenna/cable input on older analog TVs.

To connect a DVD player to a TV that only has an antenna/cable connection, you need a device referred to as an RF Modulator, which is placed between the DVD player and the TV.

For illustrated step-by-step instructions for connecting an RF modulator, TV, and DVD player together, refer to Setup 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, 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 on the discs to store the video and audio information, but there is a difference between how the "pits" and "bumps" are created on commercial DVDs vs home-recorded DVDs.

  • Commercial DVD movies are manufactured with a stamping process, 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).
  • DVDs made at home on a DVD recorder or a PC are "burned".

DVD Players and Progressive Scan

Standard video, such as from VHS VCRs, camcorders, and most TV broadcasts is displayed on a screen (such as CRT displays) as a result of scanning series of lines on a screen surface in a format called interlaced scan. Interlace Scan is 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.

An interlaced scanned frame is made up of two fields of video (that is where the term "interlaced scan" comes from). 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 perceives the video on the screen as a complete image.

Progressive scan images differ from interlaced scan images 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. In other words, 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, smoother, more detailed, images can be produced on the screen that is perfectly suited for viewing fine details, such as text and is also less susceptible to flicker.

In order to access a DVD player's progressive scan feature, you must have a TV that can display progressively scanned images, such as an LCD, Plasma, OLED TV, or LCD and DLP video projector.

A DVD player's progressive scan feature can be turned off or on. This means you can still use the player with a TV that can only display interlaced scanned images (such as an older CRT set).

For more details, refer to our companion 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, digitally encoded video, audio, and/or still image information stamped (commercial) or burned (home recorded) - they are also different.

The primary difference is that the size of the pits or burned surface of DVDs and CDs are different. As a result, they each require that the reading laser 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.

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 to also 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.

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. This is due to their higher-end audio processing circuitry. Also, as a result of the popularity of DVD players, it is becoming harder to find CD-only players. Most CD-only players available these days are either mid or 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 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, maximizing the quality of the DVD format. The colors have more depth and variation and there are 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 disc.

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 A Look at Superbit (DVD Talk) and 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 in which as the disc has 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 of the CD Patents, do not authorize the use of the official CD label on DualDiscs.

For information on whether your own DVD player is compatible with DualDisc, check your user guide, contact tech support, or go to the webpage of the manufacturer of your DVD player.

Blu-ray/DVD Flipper Discs

Another "Dual" type 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 and CDs.

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 to 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 for 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 or HDMI connection. These connections can transfer video from a DVD player to an HDTV that has the same type of video connections in pure digital form, as well as allow for "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. If you have a 1080p or 4K Ultra HD TV - the 1080p setting would deliver the best results.

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 a true high-definition video. 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.

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 HDTVs. However, DVD is not a high definition format.

For many consumers, 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 supersedes the video quality of DVD. For more details on Ultra HD Blu-ray Disc players, refer to our companion article: Before You Buy an Ultra HD Blu-ray Player.

More On DVD

Of course, there is more to the DVD story - check out our companion article: DVD Recorder FAQs