1080p
1080p is a high-definition video format with resolution of 1920 x 1080 pixels. The "p" stands for progressive scan, which means that each video frame is transmitted as a whole in a single sweep. The main advantage of 1080p TVs is that they can display all high-definition video formats without downconverting, which sacrifices some picture detail.
16:9
See aspect ratio.
3-2 pulldown processing
A process which improves the look of film-based video when it is converted to progressive-scan. The frame rate for film is 24 frames per second (24 fps), and that's the way movies are stored on DVD. The frame rate for broadcast video in the U.S. is 30 frames per second (or more precisely, 60 fields per second).
So, one of the primary tasks of the MPEG decoder inside every DVD player is to take the 24 fps data stored on the DVD and convert it to 60-fields-per-second video for TV viewing. Since 24 doesn't divide evenly into 60, a process called "3-2 pulldown" is employed, where 3 video fields are created from the first film frame, then 2 fields from the next frame, then 3, then 2, 3-2-3-2-3-2, etc. The result is 60-fields-per-second interlaced-scan video, and that's the end of the story for non-progressive-scan DVD players.
Progressive-scan DVD players add an important additional step to create a better-looking picture — they generate a progressive-scan video signal through a process called de-interlacing (sometimes called "line-doubling"). The de-interlacer's first task is to look at the interlaced video signal as it leaves the MPEG decoder and determine whether its original source was 24-frame-per-second film or 30-frame-per-second video. The original frame rate determines the type of processing necessary to create an optimized progressive-scan signal.
Advanced de-interlacers detect 3-2 pulldown on film-based sources and apply 3-2 pulldown processing to create a 60-frame-per-second progressive-scan signal that maintains the original frame integrity, with no mixing of non-matching fields. This processing reduces jagged edges on still objects and moving angled lines, producing video with the naturally smooth look of film.
Other names for 3-2 pulldown processing include "3-2 pulldown detection," "3-2 pulldown compensation," and "reverse 3-2 pulldown."
4:3
See aspect ratio.
Anamorphic
A type of widescreen display format commonly found on DVD movies. It is optimized for playback on a TV with 16:9 aspect ratio. On a standard TV, anamorphic material looks horizontally squeezed. Anamorphic DVDs are often labeled on their cases "enhanced for 16x9 televisions," "enhanced for widescreen televisions," "16x9 anamorphic," or "anamorphic widescreen."
An anamorphic widescreen DVD has significantly higher resolution than a letterboxed widescreen DVD. For example, for a film shot in the commonly used 1.85:1 aspect ratio, a letterboxed DVD presentation uses only 345 vertical scan lines (the remaining scan lines are taken up by the horizontal black bars above and below the image). That same film in anamorphic widescreen will use anywhere from 460 to the full 480 scan lines. See aspect ratio below for more information.
Aspect ratio
The shape of an image or display screen expressed as a width-to-height ratio. The NTSC television standard is the familiar squarish 4:3 (1.33:1), while anamorphic DVDs and high-definition TV broadcasts are in the wider 16:9 (1.78:1) shape. Most movies are made for the wide screen of a theater, and are originally displayed at the wider ratios of 1.85:1 or 2.35:1.
DVD's data storage capacity makes it possible to include multiple versions of a movie on a single disc. It's not unusual for a DVD disc to feature a Standard (4:3) version on one side and a Widescreen version on the other.
See our aspect ratio article for more information.
BD-Live
Interactive features found on some Blu-ray discs. While these features vary from disc to disc, they typically range from behind-the-scenes videos to additional bonus content and online games you can download via your broadband Internet connection. BD-Live-capable players include an Ethernet port, and must also support at least 1GB of flash memory for storing downloaded content. This memory can either be built into the player or achieved through the use of a removable device such as an SD™ memory card or USB thumb drive. Blu-ray players that support BD-Live are also known as Profile 2.0.
Bitstream
A signal that contains digital data in its undecoded state. An example is the signal that's fed through a DVD player's digital output(s), which carries Dolby Digital, DTS, or PCM signals.
Blu-ray Disc™
Blu-ray Disc is a high-definition disc format designed specifically for HDTVs. It offers a much greater storage capacity than DVD for more a full high-def pictureup to 1080p and more detailed sound. In February 2008, Blu-ray won a format war with a competing high-def disc format, HD DVD. See our article on Blu-ray for more information.
BonusView
A feature found on some newer Blu-ray discs and players. It allows the player to play two different audio and video streams simultaneously, making it essentially the same as picture-in-picture. BonusView is often used for director's commentary. The player displays the movie in its original, full-screen form while also playing video commentary from the film director on a smaller, inset screen. Blu-ray players with this function are also called Final Standard Profile or Profile 1 v1.1.
Cable box control
Some DVD recorders can control major brands of cable boxes. This is useful for making unattended timer recordings, because the cable box will automatically be changed to the right station at the right time.
Chrominance
The color information portion of a video signal that describes an image's color shade and vividness.
Coaxial digital output
See digital output.
Component video
A video signal in which the chrominance (color) and luminance (brightness) portions of the signal are processed separately. Component video signals provide greater color accuracy than S-video or composite signals.
All current DVD players and TVs include 3-jack component video connections. |
Why is component video superior to S-video? Where S-video separates the luminance and chrominance portions of the signal, component video goes a step further and splits the chrominance portion into two components. The benefits — improved color accuracy and less color bleeding — are especially noticeable on larger-screen TVs. And unlike S-video and composite video, component video can carry 720p and 1080i high-definition resolutions.
Composite video
A video signal in which the brightness and color portions of the signal are combined. Examples of composite video include standard VHS, laserdisc, and regular broadcast TV. A DVD player's yellow standard RCA-type video jack provides a composite video signal.
Copy protection
A system for preventing the unauthorized reproduction of copyrighted media like movies or music. The DVD format includes both digital and analog forms of copy protection. You will probably not be able to copy DVDs with your VCR. (In fact, because the copy protection system is triggered by a circuit found in most VCRs, simply playing a DVD and running the signal through your VCR will often result in a distorted picture. You should bypass the VCR altogether and connect your DVD player directly to your TV.)
Blu-ray and upconverting DVD players have a form of digital copy protection known as HDCP.
Deep Color
A color resolution standard associated with high-definition TVs, Blu-ray players, and other video gear that include HDMI 1.3 connections. Deep Color supports 10-bit, 12-bit and 16-bit color bit depths, up from 8-bit, which is the current standard for consumer video. (Because video is based on three primary colors, you'll sometimes see Deep Color described as 30-bit, 36-bit and 48-bit.) A higher color bit depth enables finer gradations between different shades of the same color, for smoother gradients and reduced color banding. Deep Color gives Blu-ray players the potential to display billions rather than millions of colors, but in order to see that improvement, the entire video production chain has to use it (camera, editing, format, player, display).
De-interlacing
The process of converting an interlaced-scan video signal (where each frame is split into two sequential fields) to a progressive-scan signal (where each frame remains whole). De-interlacers are found in progressive-scan DVD players and digital TVs. More advanced de-interlacers include a feature called 3-2 pulldown processing. With TVs, de-interlacing is sometimes referred to as "line-doubling."
Digital output
All DVD players include at least one digital audio output for sending the Dolby Digital or DTS bitstream to a compatible decoder (which is usually built into an A/V receiver). Digital data transfer offers extremely wide bandwidth, immunity to RF interference, and an easy one-cable connection.
The two most common types of digital output are coaxial and optical. Although a coaxial digital jack looks like a standard RCA-type audio jack, both coaxial and optical jacks require special cables to connect to the digital input of your Dolby Digital/DTS-equipped receiver. Note: Most DVD players do not include digital cables.
Digital-to-analog converter (DAC)
An electronic circuit that converts a series of digital "words" into a continuous analog signal. DVD players include separate DACs for audio and video.
Disc capacity
The number of discs a DVD player or changer can hold.
DivX®
A technology that compresses a video file to a fraction of its original size for easy storage and sharing, just as MP3 does for music files. Some DVD and Blu-ray players can play DivX files recorded to CDs or DVDs.
Dolby® Digital
Dolby Digital is normally associated with 5.1-channel surround sound. It is referred to as a 5.1-channel system because it offers five full-bandwidth channels (including true stereo surrounds), plus a "low frequency effects" subwoofer channel. Though this channel configuration is common, it is only one of several possible variations — a "Dolby Digital" soundtrack can mean anything from 1 to 5.1 channels.
If you're specifically looking for titles with a 5.1 soundtrack, you should carefully read each DVD's packaging. Relatively few older movies with stereo or mono soundtracks will be remastered with 5.1-channel surround for DVD.
Unless your DVD player has its own built-in Dolby Digital decoder, you'll need to connect your player to a receiver via optical or coaxial digital audio, or via HDMI. Your receiver will decode the Dolby Digital signal, and transform it into multichannel sound.
You can also find newer versions of Dolby Digital on some Blu-ray Discs. Dolby Digital Plus can provide up to 7.1 channels of audio. It uses less compression than Dolby Digital, delivering greater sonic detail. Dolby TrueHD also supports soundtracks up to 7.1-channels, and uses "lossless" compression for the closest possible reproduction of the studio's original master. You'll need to connect your Blu-ray player to a compatible receiver via HDMI or a multichannel analog connection to take advantage of these new formats. (See our article on Blu-ray players for more information.) Our surround sound formats article includes more info on the latest varieties of Dolby Digital and DTS.
Downmixed audio
If you don't have a Dolby Digital system, you can still enjoy excellent Dolby Surround (formerly "Pro Logic®") or stereo sound. All DVD players have the ability to take a 5.1-channel Dolby Digital soundtrack and "downmix" it to two channels, which can then be sent to a stereo TV, a stereo receiver, or to an A/V receiver with Dolby Pro Logic decoding.
DTS® (Digital Theater Systems)
DTS is a well-established multichannel audio format in movie theaters, but not as common in home theater applications. Like Dolby Digital, DTS is primarily a 5.1-channel format. The compression scheme used in DTS "throws away" significantly less audio data than Dolby Digital, so theoretically it should sound better, but so far, side-by-side comparisons have been inconclusive.
Nearly all new DVD players and A/V receivers include DTS decoding. Still, the number and availability of DVD titles with DTS soundtracks remains somewhat limited.
Some high-definition Blu-ray discs use newer versions of DTS — DTS-HD™ (also known as "DTS-HD High Resolution") and DTS-HD Master Audio. Like Dolby Digital Plus, DTS-HD uses less compression than its DVD counterpart for a more accurate reproduction of a movie's soundtrack. DTS-HD Master Audio uses "lossless" compression for the closest possible reproduction of the movie studio's original master. See our article on understanding surround sound formats for more information.
DualDisc
A DualDisc is a new two-sided disc that combines audio on one side with a DVD on the other side. The audio side carries stereo music, while the DVD side usually offers a multichannel version in Dolby Digital, DTS, or DVD-Audio in addition to video footage. Extras can include lyrics, documentaries, interviews, photo galleries, and more.
A DualDisc will probably play in most CD or DVD players. However, since DualDisc is slightly thicker than regular CDs, it may get stuck in some slot-loading players, or the DVD side may get scratched. A number of consumer electronics manufacturers have posted advisories regarding these issues, including Denon, JVC, Onkyo, Sony, and Toshiba.
Keep in mind, if the DualDisc has DVD-Audio content on the DVD side, you'll need a DVD-Audio-capable player in order to listen to that portion of the disc. Even if you don't have a DVD-Audio player, most discs will have a multichannel Dolby Digital mix in addition to DVD-Audio, so that they can still be played in a regular DVD player.
DVD-Audio (DVD-A)
A music-oriented DVD format that can carry up to 6 channels of 96kHz/24-bit audio (music for 5.1-channel home theater systems), or 2 channels of ultra high-resolution 192kHz/24-bit audio. Most DVD-Audio discs also carry lower-resolution Dolby Digital or stereo soundtracks for playback on DVD players that lack DVD-Audio decoders. A DVD-Audio disc may also contain liner notes, lyrics, menus, and still pictures that display on your TV.
DVD-R/RW, DVD-RAM, DVD+R/RW
See recordable DVD.
DVI (Digital Visual Interface)
A multi-pin computer-style output included on a few DVD players. DVI provides an "upconverted" or upgraded DVD video signal to HD-compatible TVs with a compatible connector. This digital video signal is encrypted with High-bandwidth Digital Content Protection (HDCP) to prevent recording.
DVR (Digital Video Recorder)
Also known as a personal video recorder (PVR) or hard disk video recorder. DVRs store recordings on a large hard drive, and most let you pause and replay live television. When used with an electronic program guide service, you can find and record shows automatically.
Electronic program guide (EPG)
Found on some DVD recorders, an EPG provides an on-screen listing of available channels and program data for an extended time period, usually 1-2 weeks. Examples of program guides include subscription services like TiVo® and free guides like TV Guide On Screen®.
Field
In interlaced-scan video, each complete frame is split into 2 sequential fields, each of which contains half the scanning lines of the frame. One field contains the odd scanning lines, and the other field the even lines.
Frame
A complete, individual picture in a movie film. In a video signal, a frame contains all of the picture's scanning lines.
Frame rate
The rate at which frames are displayed. The frame rate for movies is 24 frames per second (24 fps). In regular NTSC video, the frame rate is 30 fps.
Hard disk video recorder
See DVR.
Hard drive size
The amount of recording space on a digital video recorder's (DVR) hard drive, generally given in GB (gigabytes). A rough rule of thumb is that 1GB = 1 hour of programming, with the approximate quality of a VHS recording. You can fit more video on the hard drive by lowering the recording quality. If you use a higher recording quality, you'll be able to fit less video.
HDCD® (High Definition Compatible Digital)
An enhanced method of audio recording for CDs developed by Pacific Microsonics. HDCD claims to be able to capture 20-bit resolution. Although the HDCD-enhanced information can only be heard using a DVD or CD player with built-in HDCD decoding, HDCD discs are still playable on regular DVD and CD players.
HDCP (High-Bandwidth Digital Content Protection)
HDCP encryption is used with high-resolution signals over DVI and HDMI connections to prevent unauthorized duplication of copyrighted material.
HD DVD
Like Blu-ray, the HD DVD format offers full HD video and improved surround sound. Since HD DVD lost the high-def disc format war, your main choice for high-def disc playback will be a Blu-ray player. For more information, check out our article about Blu-ray.
HDMI (High-Definition Multimedia Interface)
Similar to DVI (but using much smaller connectors), the multi-pin HDMI interface transfers uncompressed digital video with HDCP copy protection and multichannel audio. Using an adapter, HDMI is backward-compatible with most current DVI connections. HDMI connectors are found on upconverting DVD players, Blu-ray players, A/V receivers, and TVs. HDMI can support all high-definition resolutions up to and including 1080p. For more information, read our article on the ins and outs of HDMI.
IEEE 1394
Also known as "FireWire" or i.LINK®, this all-in-one, high-speed digital interface is becoming an industry standard for the transmission of digital audio/video data. It permits data transfer between compatible digital components, such as a camcorder and DVD recorder, with virtually zero loss in video or audio quality.
Interlaced scan
DVDs use 480 lines to make up a frame (picture). The frame is made up of two fields: The first field has 240 odd lines (1,3,5...) and the second field has 240 even lines (2,4,6...). The odd lines are scanned (drawn on the screen) in 1/60th of a second, and the even lines follow in the next 1/60th of a second. This presents an entire frame/picture of 525 lines in 1/30th of a second. See also progressive scan.
IR blaster
A device that enables a DVD recorder or DVR to control your cable box or satellite receiver by sending signals that mimic those of a remote control. An IR blaster, or flasher, looks like a regular cable with two distinctly different ends. One end plugs into the back of a compatible DVD recorder or DVR. The other end is the IR emitter. It sits in front of the cable box/satellite receiver's IR sensor, which is located on the front-panel. IR blasters make for easier unattended timer recordings, since the DVD recorder/DVR can tune the set-top box to the right channel at the right time.
JPEG CD
JPEG is a way to encode full-color digital images so that they're smaller and easier to store and transfer. Its compression takes advantage of the human eye's inability to see minute color changes by removing portions of data from the original picture file. Many DVD players, DVD recorders, and Blu-ray players can read JPEG files burned to a CD, and display them on a TV.
Letterboxing
The scaling of a widescreen image to fit a standard 4:3 aspect ratio TV screen by shrinking the image so that the width fits exactly. The horizontal black bars that appear above and below the image are actually recorded with the picture, so some of the picture's vertical resolution is lost when you view it. Letterboxing is much more common on DVD movies than VHS videos.
Luminance
The brightness component of a color video signal. Determines the level of picture detail.
MLP (Meridian Lossless Packing)
A lossless compression technique (used on DVD-Audio discs) that removes redundancy from PCM audio signals. MLP achieves a compression ratio of about 2:1 while allowing the signal to be perfectly re-created by an MLP decoder.
MPEG2
The digital video signal compression standard used for DVD. This adaptive, variable bitrate process is able to allocate more bits for complex scenes involving a lot of motion, while minimizing the bits in static scenes. The average data rate for DVD is 3.5 Mbps (million bits/second).
MPEG stands for Moving Picture Experts Group.
Multi-language capability
DVD and Blu-ray Disc are designed to make it easier for movies to be distributed in multiple languages. A single disc can contain soundtracks in up to 8 different languages.
In addition to multilingual dialogue, Blu-ray and DVD discs also have space for subtitles in up to 32 languages. Note: the number of soundtracks and subtitles will vary from disc to disc depending on the length of the movie and whether or not other special playback features are included.
Optical digital output
See digital output.
Pan-and-scan
A technique for making a widescreen movie fit a standard TV's 4:3 aspect ratio by showing only selected portions of the original image. This is the standard practice on VHS videos ("formatted to fit your screen"), but is less common on DVDs.
Parental lockout
A small percentage of DVD movies include variable ratings capability. According to the movie rating level you select, the player will skip over certain scenes, playing the version that you choose from those available on the disc.
PCM (Pulse Code Modulation)
Uncompressed digital audio. PCM is the standard audio format for CDs and Blu-ray Disc. Digital outputs on DVD players are often labeled "Bitstream/PCM" because they can send the Dolby Digital or DTS bitstream from a DVD, or the PCM bitstream from a CD.
Perceptual coding
A type of data compression used in recent digital audio and video formats. Audio examples include Dolby Digital and MP3. The best example of video compression is MPEG2, which is used for DVD and most digital satellite TV. These forms of data compression are based on sophisticated research into how we perceive sounds and images.
Perceptual coding omits "imperceptible" sound and picture data which is redundant or which is judged to be masked by similar information. In the case of DVD, by "throwing away" a lot of redundant and unnecessary information, it's possible to fit multiple versions of a movie on a single 5-inch disc.
Personal Video Recorder (PVR)
See DVR.
Profile 1.1
See BonusView.
Profile 2.0
See BD-Live.
Progressive scan
A feature on all current DVD players, as well as many older models. Instead of splitting each video frame into two sequential fields like interlaced scan, progressive scan displays the entire frame in a single sweep. So, where an interlaced signal from a DVD player (480i) displays 30 frames (60 fields) per second, a progressive-scan signal (480p) displays 60 full frames per second. Progressive-scan picture quality is more filmlike, with more fine detail and less flicker. Watching progressive-scan signals requires a compatible digital TV (EDTV, HDTV-ready, or full HDTV). To ensure that progressive-scan players are still compatible with analog TVs, they have selectable outputs for interlaced or progressive signals. Also see interlaced scan.
 Interlaced scan splits the image into two fields, alternating between the even (2,4,6...) and odd (1,3,5...) scan lines every 1/60th second, and effectively displaying a full frame every 1/30th second.
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Recordable DVD
The popularity of DVD technology led to machines that not only play DVDs, but record on them, too. Recordable DVD combines high-quality audio/video recording with tape-free convenience.
There are three competing recordable-DVD camps, backed by various electronics and computer companies. These three camps are DVD-R/RW, DVD-RAM, and DVD+R/RW. Some of these formats use discs that can only be recorded once; others use discs that can be erased and re-recorded.
- Write-once: DVD-R, DVD+R
- Rewriteable: DVD-RW, DVD+RW, DVD-RAM
For more details on recordable DVD, see our DVD Recorders article.
Region codes
The movie industry insisted that the DVD and Blu-ray standards include codes which would limit playback to a specified geographical region. This was done because theater and home video releases of movies do not occur simultaneously worldwide. For example, a movie may be released on video in the U.S. just as it's first appearing in theaters in Europe.
DVD and Blu-ray players have a built-in region code lockout feature, while the discs may or may not contain a code (region codes are optional on software). A player will be unable to play a disc that has a different region code. Discs may contain codes for more than one region, or may not have any code, which allows them to be played on any player in any country. The DVD region code for USA/Canada is "1". For Blu-ray, the United States is part of Region "A." Note: Many recent DVDs will not play in modified "code-free" DVD players.
Scaler
Circuitry that converts a video signal to a resolution other than its original format. Many DVD players — typically those that include a DVI or HDMI input — are able to "upconvert" the DVD signal to a higher resolution, such as 720p or 1080i for displaying on an HD-compatible TV. Blu-ray players have similar capabilities. Also see video upconversion.
Signal-to-Noise ratio (video)
This ratio is a measure of the content portion of the video signal in relation to the noise in the signal. As with audio, video signal-to-noise is measured in decibels (dB). The way the decibel scale works, if component A has a signal-to-noise (S/N) ratio of 20 dB and component B has a S/N ratio of 30 dB, component B will have ten times less noise in the signal than component A.
Basically, a S/N ratio tells you how "clean" a video signal is. Because of the way they process signals, digital video formats like DVD and digital satellite TV are extremely clean. A standard VHS VCR may have a S/N spec in the low 40s; a laserdisc player, the low 50s. DVD is rated to deliver a video S/N ratio of 65 dB.
Super Audio CD (SACD)
A high-resolution digital audio format developed by Sony and Philips. SACDs sound more detailed than standard CDs, with greater dynamic range. All SACDs contain a high-resolution stereo mix; many also contain a high-resolution surround mix, with up to 6 independent channels. See our article on SACD and DVD-Audio for more information.
S-video
This video connection carries the chrominance (color) and luminance (brightness) portions of the video signal in separate streams, for improved color accuracy and reduced distortion. S-video provides a sharper picture than composite video, but is not as good as component video.
TiVo
A subscription service that popularized DVRs. Includes a 14-day program guide, WishList™ (search and record), Season Pass™ (record whole seasons of a program), and more.
TiVo Series2™
The second generation of TiVo boxes, first available in 2002. Series2 boxes support free Home Media networking features. Also, Series2 boxes that don't have a built-in DVD recorder support TiVoToGo™, which lets you save your TV recordings to your desktop or laptop PC.
TV Guide On Screen interactive program guide
A free service included with the purchase of some digital video recorders (DVRs), DVD recorders, and TVs. Includes an 8-day program guide, handy searching functions, and smart recording features.
Video upconversion
A feature found on many newer DVD players, and even some recorders. "Upconversion" is the term used to describe the conversion of a lower image resolution to an apparently higher one. In order to achieve that higher resolution, the player fills in additional image data by assessing existing pixels and intelligently predicting what the surrounding pixels should look like.
Upconversion is a great feature for owners of HDTVs who want to watch their DVDs at a higher resolution that more closely matches the capabilities of their TV. Upconverted video is typically only available via a digital connection like HDMI. Though the quality of upconverted signals can vary from model to model, upconversion generally makes for a better picture.
WMA CD
WMA stands for Windows® Media Audio. Like MP3, WMA compresses audio files for easier storage. Some DVD players and recorders, as well as a handful of Blu-ray players, can read WMA files burned to a CD.
x.v.Color™
A high-definition video color space supported by some Blu-ray players and HDTVs (generally models with HDMI v1.3 inputs). The x.v.Color standard supports 1.8 times as many colors as the digital ATSC broadcast standard. There are currently no broadcast or packaged consumer high-def sources that support it, but you can find it on some camcorders. If Blu-ray discs encoded with x.v.Color become available in the future, you'll be able to see a wider range of colors as long as your Blu-ray player and HDTV also support it.
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