| 1080i |
The picture is displayed as 1920x1080 pixels at 60 interlaced frames per second (30 complete frames per second). |
| 1080p |
The picture is displayed as 1920x1080 pixels at 60 full frames per second. |
| 16:9 (wide screen) |
The aspect ration of a wide-screen TV. Easily shows the full original image of big screen films without having to use a letterbox. DVDs and HDTV broadcasts are formatted in the aspect ratio. |
| 4:3 (standard screen) |
The aspect ratio of a traditional TV set. Nearly square shaped. Works well for broadcasts but it is difficult to preserve the look of big screen films. To do this, about 25% of the image must be removed to show the image "full screen," or the bottom and top of the TV screen must be blacked out (called a "letterbox"). |
| 480i = 525i |
The picture is displayed as 704x480 or 720x480 pixels at 60 interlaced frames per second (30 complete frames per second). |
| 480p = 525p |
Also generally considered SDTV, sometimes referred to as EDTV. The picture is displayed as 704x480 or 720x480 pixels at 60 full frames per second. |
| 576=625i |
The picture is displayed as 704x576 or 720x576 pixels at 50 interlaced frames per second (25 complete frames per second). |
| 720p |
The picture is displayed as 1280x720 pixels at 60 frames per second. |
| AAC |
Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. AAC generally achieves better sound quality than MP3 at the same bitrate, particularly below 192 kbit/s. |
| AC-3 |
Dolby Digital, or AC-3, is the common version containing up to six discrete channels of sound, with five channels for normal-range speakers (20 Hz – 20,000 Hz) (right front, center, left front, right rear and left rear) and one channel (20 Hz – 120 Hz) for the subwoofer driven low-frequency effects. |
| AES-EBU |
The digital audio standard frequently called AES/EBU, officially known as AES3, is used for carrying digital audio signals between various devices. It was developed by the Audio Engineering Society (AES) and the European Broadcasting Union (EBU) and first published in 1989 (Watkinson, 1989), later revised in 1995, 1998, and 2003. |
| Analog Television |
Currently the most common type of television set and television broadcast signal. Uses radio frequency waves to transmit and display pictures and sound. In broadcast, each frame of video contains approximately 480 active lines of information. Each frame of video is beamed to the TV screen using interlaced scanning. NTSC Standard Analog TV resolution is referred to as 480i. PAL Standard Analog TV resolution is referred to as 576. |
| ASI |
Asynchronous Serial Interface, or ASI, is streaming format much like an MPEG Transport Stream MPEG-TS. It can contain a single program or be a multiplex of multiple programs, each consisting of video and audio. It is electrically identical to an SDI signal. |
| Aspect Ratio |
The ratio of the width of the picture to the heigh. For most TV sets this ratio is 4:3. For HDTV, the ratio is 16:9. |
| AVC |
H.264 is a standard for video compression. It is also known as MPEG-4 Part 10, or MPEG-4 AVC (for Advanced Video Coding). It was written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 Part 10 standard (formally, ISO/IEC 14496-10) are jointly maintained so that they have identical technical content. The final drafting work on the first version of the standard was completed in May 2003. |
| AVI |
Audio Video Interleave, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a standard container that allows synchronous audio-with-video playback. |
| Back Porch |
The area of the video waveform between the rising edge of the horizontal sync and right before the active video. |
| BMP |
The BMP file format, sometimes called bitmap or DIB file format (for device-independent bitmap), is an image file format used to store bitmap digital images, especially on Microsoft Windows and OS/2 operating systems. |
| Brightness |
How much light is emitted by the display |
| Chroma |
The NTSC or PAL video signal contains two pieces that make up what you see on the screen: the black and white (luma) and the color part (Chroma) |
| Component video |
A three-wire standard for connecting DVD players to TVs or monitors delivers HD resolutions. Component video is capable of producing signals such as 480p, 576p, 720p, 1080i, and 1080p, but, according to some, digital connections such as DVI (video only) and HDMI (which can also include up to 8 channels of audio) generally give better results at the higher resolutions (up to 1080p). HDMI also includes both a video and audio signal in a single cable. |
| Composite video |
A one-wire standard delivers all video information for NTSC, PAL standard. The format of an analog television (picture only) signal before it is combined with a sound signal and modulated onto an RF carrier. Not used for HDTV. |
| Contrast |
How far the whitest whites are from the blackest blacks. If the two are very close to each other, the image will appear washed out. If the two are very far apart, then the image is very stark. |
| dB |
Abbreviate for Decibels. As standard for expressing relative power. dB = 10log(10) (P1/P2). |
| Digital Video |
Video images stored, broadcast or displayed in a digital format |
| DSUB |
The D-subminiature or D-sub is a common type of electrical connector used particularly in computers. Calling them "subminiature" was appropriate when they were first introduced, but today they are among the largest common connectors used in computers. VGA is a type of DSUB connector. |
| DTV |
Includes some broadcast TV stations, DBS (direct broadcast satellite), and digital cable television. Video is converted to a digital stream of information using a codec, and is then decoded for display on consumers' television sets by the sets themselves or by set-top boxes. The term can also refer to the actual TV set capable of receiving digital broadcasts. Digital TeleVision includes HDTV and SDTV. |
| DVB |
DVB, short for Digital Video Broadcasting, is a suite of internationally accepted open standards for digital television. DVB standards are maintained by the DVB Project, an industry consortium with more than 270 members, and they are published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU). |
| DVI |
Digital Video Interface is a video interface standard designed to maximize the video quality of digital display devices such as flat panel LCD computer displays and digital projectors. It was developed by an industry consortium, the Digital Display Working Group (DDWG). |
| EBU |
The European Broadcasting Union (EBU; French: L'Union Européenne de Radio-Télévision ("UER"), and unrelated to the European Union) was formed on 12 February 1950 by 23 broadcasting organisations from Europe and the Mediterranean at a conference in the coastal resort of Torquay in Devon, England. |
| EDID |
Extended display identification data (EDID) is a data structure provided by a computer display to describe its capabilities to a graphics card. It is what enables a modern personal computer to know what kind of monitor is connected. EDID is defined by a standard published by the Video Electronics Standards Association (VESA). |
| EDTV |
Enhanced Definition TeleVision is another name for 480p. The "p" stands for progressive scan, which solves the problem of picture-quality loss seen when interlaced signals are displayed on larger television screens. In progressive format, all 480 lines of information are sent to the screen in one pass, from top to bottom. |
| Frame Rate |
Number of video frames displayed per second. Higher frame rates usually produce smoother movement in the picture. Film typically has 24 frames per second and video has 25 or 30 frames per second. |
| Front Porch |
The area of the video waveform between the start of the horizontal blank and the falling edge (start of) the horizontal sync. |
| Gamma |
A small change in voltage when the voltage levels are low of a display produces a change in the brightness level. This same change at high voltage does not produce the same magnitude of change. The difference between what you should have and what you actually get is known as Gamma. |
| GIF |
The Graphics Interchange Format (GIF) is an 8-bit-per-pixel bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability. |
| GUI |
A Graphical User Interface (GUI) is a type of user interface which allows people to interact with a computer and computer-controlled devices. Instead of offering only text menus, or requiring typed commands: graphical icons, visual indicators or special graphical elements called "widgets", are presented. Often the icons are used in conjunction with text, labels or text navigation to fully represent the information and actions available to a user. The actions are usually performed through direct manipulation of the graphical elements. |
| HD |
High Definition r efers to any video signal displayed at 1280x720 pixels or better. May also refer to any display capable of showing this resolution |
| HDCP |
A form of digital rights management (DRM) developed by the Intel Corporation to control digital audio and video content as it travels across Digital video Interface (DVI) or High Definition Multimedia Interface (HDMI) connections. The High-bandwidth Digital Content Protection specification is proprietary and an implementation of HDCP requires a license. |
| HDMI |
High Definition Multipurpose Interface supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It is independent of the various DTV standards such as ATSC, and DVB(-T,-S,-C), as these are encapsulations of the MPEG data streams, which are passed off to a decoder, and output as uncompressed video data, which can be high-definition. HDMI also includes support for 8-channel uncompressed digital audio. |
| HD-SDI |
High Definition Serial Digital Interface s tandardized in SMPTE 292M; this provides a nominal date rate of 1.485 Gbit/s. An emerging interface, commonly known in the industry as dual link and consisting essentially of a pair of SMPTE 292M links, is standardized in SMPTE 372M; this provides a nominal 2.970 Gbit/s interface used in applications |
| HDTV |
High Definition TeleVision formats are the highest-resolution formats of DTV. HDTV is generally considered to be 1,080-line interlaced (1080i) or 720-line progressive (720p). The term may also refer to any actual television set that displays 1280x720 pixels or better. |
| Horizontal resolution |
The number of vertical lines from one side of an image to the other. The horizontal resolution of both NTSE standard analog and ATSC stand digital video may vary according to the source. |
| Hue |
Hue refers to the wavelength of the color. The hue is in terms of the base color - red, green, yellow, etc. A red hue could look brown at low saturation, bright red at higher saturation, or pink at high brightness. |
| HVS |
Human Visual System has the complex task of constructing a three dimensional world from a two dimensional projection of that world. Algorithms try to mimic this by taking into account spatial and temporal properties and ignoring things outside the visible wavefront. |
| ICC |
(International Color Consortium) Profiles describe the color attributes of a particular device or viewing requirement by defining a mapping between the source or target color space and a profile connection space. |
| Interlaced scan |
Each frame of video is beamed to the TV screen in two passes lasting 1/60th of a second each. Odd numbered lines are displayed first, top to bottom in 1/60 of a second. Next, even numbered lines are displayed, from bottom to top. All together it takes 1/30 second to display an entire frame. |
| ITU |
The International Telecommunication Union is an international organization established to standardize and regulate international radio and telecommunications. |
| JND |
In psychophysics, a just noticeable difference, customarily abbreviated with lowercase letters as jnd, is the smallest difference in a specified modality of sensory input that is detectable by a human being. It is also known as the difference limen or the differential threshold. |
| Luma |
The NTSC or PAL video signal contains two pieces that make up what you see on the screen: the black and white (luma) and the color part (Chroma) |
| LUT |
A lookup table is a data structure, usually an array or associative array, used to replace a runtime computation with a simpler lookup operation. The speed gain can be significant, since retrieving a value from memory is often faster than undergoing an expensive computation. |
| MP3 |
MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a lossy compression and encoding scheme for digital audio. |
| MPEG-1 |
Initial video and audio compression standard. Later used as the standard for Video CD, and includes the popular Layer 3 (MP3) audio compression format. |
| MPEG-2 |
Transport, video and audio standards for broadcast-quality television. Used for over-the-air digital television ATSC, DVB and ISDB, digital satellite TV services like Dish Network, digital cable television signals, and (with slight modifications) for DVDs. |
| MPEG-2 PS |
Program stream (PS or MPEG-PS) is a container format for multiplexing digital audio, video and more. The PS format is specified in MPEG-1 Systems and MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1). Program streams are created by combining one or more Packetized Elementary Streams (PES), which have a common time base, into a single stream. It is designed for reasonably reliable media such as disks, in contrast to transport stream which is for data transmission in which loss of data is likely. Program streams have variable size records and minimal use of start codes which would make over the air reception difficult. |
| MPEG-2 TS |
Transport stream (TS, TP, MPEG-TS, or M2T) is a communications protocol for audio, video, and data which is specified in MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1). Its design goal is to allow multiplexing of digital video and audio and to synchronize the output. Transport stream offers features for error correction for transportation over unreliable media, and is used in broadcast applications such as DVB and ATSC. It is contrasted with program stream, designed for more reliable media such as DVDs. |
| MPEG-3 |
Originally designed for HDTV, but abandoned when it was discovered that MPEG-2 was sufficient for HDTV. |
| MPEG-4 |
A standard used primarily to compress audio and video (AV) digital data. Introduced in late 1998, it is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). The uses for the MPEG-4 standard are web (streaming media) and CD distribution, conversation (videophone), and broadcast television, all of which benefit from compressing the AV stream. |
| MPEG-4 part 10 = MPEG-4/AVC = H.264 |
A compression codec for video signals which is technically identical to the ITU-T H.264 standard. This standard is being widely used for HD-DVD, IPTV, and HD Terrestrial and Satellite broadcast. |
| MPEG-4 part 2 = MPEG-4/ASP |
A compression codec for video data (video, still textures, synthetic images, etc.). One of the many "profiles" in Part 2 is the Advanced Simple Profile (ASP). |
| MPEG-7 |
A formal system for describing multimedia content. This is not a compression format. |
| MXF |
MXF is a "container" or "wrapper" format which supports a number of different streams of coded "essence", encoded with any of a variety of codecs, together with a metadata wrapper which describes the material contained within the MXF file. MXF was developed to carry a subset of the Advanced Authoring Format (AAF) data model, under a policy known as the Zero Divergence Directive (ZDD). This enables MXF/AAF workflows between non-linear editing (NLE) systems using AAF and cameras, servers, and other devices using MXF. |
| NTSC |
NTSC is the analog television system in use in the United States, Canada, Japan, Mexico, the Philippines, South Korea, Taiwan, and some other countries, mostly in the Americas (see map). It is named for the National Television System Committee, the U.S. standardization body which adopted it. |
| Objective Video Assessment |
The objective evaluation techniques are mathematical models that successfully emulate the subjective quality assessment results, based on criteria and metrics that can be measured objectively. The objective methods are classified, according to the availability of the original video signal, which is considered to be in high quality. Therefore, they can be classified as Full Reference Methods, Reduced Reference Methods and No-Reference Methods. The most traditional way of evaluating the quality of digital video processing system is counting of the peak signal-to-noise ratio (PSNR) between source signal and video passed through this system. PSNR is one of objective video quality metrics - metrics that can be automatically computed by a computer program. Recently a number of more complicated and precise metrics were developed, for example VQM and SSIM. |
| PAL |
Phase Alternation by Line (PAL) is a color encoding system used in broadcast television systems in large parts of the world. The term "PAL" is often used informally to refer to a 625-line/50 Hz (principally European) television system, and to differentiate from a 525-line/60 Hz (principally North American/Central American/Japanese) "NTSC" system. |
| Pixel |
Picture Elements (Pixel) are the tiny dots that make up the picture on a television screen. They are the smallest units of video information. |
| PNG |
Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace the GIF format, as an image-file format not requiring a patent license. |
| Progressive scan |
All horizontal scan lines of a video frame, even and odd, are beamed to the screen at one time, from top to bottom. Unlike interlaced scanning, progressive scanning eliminates the need to separate each frame into two fields. Therefore it takes half the time to display an entire frame of video. This doubles the frame rate to 60 full frames per second. Newer LCD and flat-screen displays are inherently progressive. |
| PSF |
A High Definition video format used to store progressive content on interlaced media. Each progressive frame is segmented into two interlaced fields without interfield motion, or "combing". Progressive Segmented Frame is an alternative to 3:2 pulldown, wherein certain frames are "pulled down" across multiple fields, resulting in output with an irregular frame rate. |
| PSNR |
The phrase Peak Signal-to-Noise Ratio, often abbreviated PSNR, is an engineering term for the ratio between the maximum possible power of a signal and the power of corrupting noise that affects the fidelity of its representation. Because many signals have a very wide dynamic range, PSNR is usually expressed in terms of the logarithmic decibel scale |
| QA/QC |
Quality Assurance / Quality Control. The people who test and approve product development. |
| RAW |
A raw image file (sometimes written RAW image file) contains minimally processed data from the image sensor of a digital camera or image scanner. Raw files are so named because they are not yet processed and ready to be used with a bitmap graphics editor or printed. |
| RGB |
The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue. |
| RGBA |
RGBA stands for Red Green Blue Alpha. While it is sometimes described as a color space, it is actually simply a use of the RGB color model, with extra information. The color is RGB, and may belong to any RGB color space, but an integral alpha value as invented by Catmull and Smith between 1971 and 1972 enables alpha blending and alpha compositing. The inventors named alpha after the Greek letter in the classic linear interpolation formula aA + (1-a)B. |
| Saturation |
The amount of color present. A lightly saturated red looks pink. While a highly saturdated red looks like a red crayon. Less saturated is effectively adding white to the pure color. |
| SD |
Standard Definition is any video signal displayed at 704x480, 720x480 or 720x576 pixels. This can refer to digital or analog signals. |
| SDI |
Serial Digital Interface is standardized in ITU-R BT.656 and SMPTE 259M, is a digital video interface used for broadcast-grade video. |
| SDTV |
In the past few years, a standard for digital video has been put in place by the ATSC called Standard Definition Television, or SDTV. 480i is an accurate designation for this format, causing some confusion between this and Analog Television. |
| SMPTE |
The Society of Motion Picture and Television Engineers or SMPTE, founded in 1916 as the Society of Motion Picture Engineers or SMPE, is an international professional association, based in the United States of America, of engineers working in the motion imaging industries. An internationally-recognized standards developing organization, SMPTE has over 400 standards, |
| S/PDIF |
S/PDIF specifies a Data Link Layer protocol and choice of Physical Layer specifications for carrying digital audio signals between devices and stereo components. The name stands for Sony/Philips Digital Interconnect Format (more commonly know as Sony Philips Digital Interface), the two companies being the primary designers of the S/PDIF format. |
| SSIM |
The Structural SIMilarity (SSIM) index is a method for measuring the similarity between two images. The SSIM index is a full reference metric, in other words, the measuring of image quality based on an initial uncompressed or distortion-free image as reference. SSIM is designed to improve on traditional methods like PSNR and MSE, which have proved to be inconsistent with human eye perception. SSIM is also commonly used as a method of testing the quality of various lossy video compression methods. |
| Subjective Video Assessment |
The main goal of many objective video quality metrics is to automatically estimate general user's opinion on a video processed by the system. But the best way to find out a user's opinion is just to ask them! Sometimes however, subjective video quality can also be challenging because it may require a trained expert to judge it. Many "subjective video quality measurements" are described in ITU-T recommendation BT.500. Their main idea is the same as in Mean Opinion Score for audio: video sequences are shown to the group of viewers and then their opinion is averaged to evaluate the quality of each video sequence, but details of testing may vary greatly. |
| S-video |
This is another type of component video signal, because the luminance and chrominance signals are transmitted on separate wires. This connection type, however, cannot produce high definition pictures with more than 480 interlaced lines of video for NTSC or more than 576 lines of interlaced video for PAL. |
| TXT |
A text file (sometimes spelled "textfile") is a generic description of a kind of computer file in a computer file system. |
| VC-1 |
A compression codec for video signals, also called SMPTE VC-1 or Microsoft Windows Video 9. This standard is being widely used for HD-DVD, IPTV, and HD Terrestrial and Satellite broadcast. |
| Vertical resolution |
The number of horizontal lines from the top of an image to the bottom. In NTSC standard analog signals this is seen as about 480 lines. ATSC standard digital video vertical resolution varies, ranging from SDTV's 480 lines to HDTV's 720 or 1080 lines. |
| VGA |
Video Graphic Adapter is an analog computer display standard first marketed in 1987 by IBM. While it has been obsolete for some time, it was the last graphical standard that the majority of manufacturers decided to follow, making it the lowest common denominator that all PC graphics hardware supports prior to a device-specific driver being loaded. |
| Video Compression |
Video compression refers to reducing the quantity of data used to represent video content without excessively reducing the quality of the picture. |
| VTR |
A video tape recorder (VTR), is a tape recorder that can record video material. The video cassette recorder (VCR), where the videotape is enclosed in a user-friendly videocassette shell, is the most familiar type of VTR known to consumers. Professionals may use other types of video tapes and recorders. |
| Y'CbCr |
Y'CbCr is not an absolute color space. It is a way of encoding RGB information, and the actual color displayed depends on the actual RGB colorants used to display the signal. Therefore a value expressed as Y'CbCr is only predictable if standard RGB colorants are used, or if an ICC profile is attached or implied which is used to translate value for the colorants in use. |
| Y'PbPr |
Y'PbPr is the analog version of the YCbCr color space; the two are numerically equivalent, but Y'PbPr is designed for use in analog systems whereas Y'CbCr is intended for digital video. Y'PbPr is commonly called "component video", but this is a misnomer, as there are many other types of component video (the most common is "RGBHV", aka "VGA" / "D-SUB"). Y'PbPr is converted from the RGB video signal, which is split into three components, Y, Pr and Pb. Y carries luma (brightness) information. Pb carries the difference between blue and luma (B - Y). Pr carries the difference between red and luma (R - Y). |
| YUV |
Y stands for the luma component (the brightness) and U and V are the chrominance (color) components. The Y'PbPr color model used in analog component video and its digital version Y'CbCr used in digital video are more or less derived from it (Cb/Pb and Cr/Pr are deviations from grey on blue-yellow and red-cyan axes, whereas U and V are blue-luminance and red-luminance differences), and are sometimes inaccurately called "YUV". |
