NationMaster - Encyclopedia: Video recording

Video is the technology of capturing, recording, processing, transmitting, and reconstructing moving pictures, typically using celluloid film, electronic signals, or digital media, primarily for viewing on television or as video clips on computer monitors. Film refers to the celluloid medium on which motion pictures are printed. ... Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents, generally regarded to be the first thermoplastic. ... Video clips are short video segments, often excerpted from a larger whole. ... A Lego RCX Computer is an example of an embedded computer used to control mechanical devices. ... A computer display A computer display (also known as a computer monitor, computer screen, or computer video display) is a device that can display signals generated by a computer as images on a screen. ...

Description

The term video (from the Latin for "I see") commonly refers to several storage formats for moving pictures: digital video formats, including DVD, QuickTime, and MPEG-4; and analog videotapes, including VHS and Betamax. Video can be recorded and transmitted in various physical media: in celluloid film when recorded by mechanical cameras, in PAL or NTSC electric signals when recorded by video cameras, or in MPEG-4 or DV digital media when recorded by digital cameras. Download high resolution version (1276x822, 58 KB) information from sources: [1], [2], NTSC, PAL, SECAM File links The following pages link to this file: NTSC PAL SÉCAM Categories: GFDL images ... Download high resolution version (1276x822, 58 KB) information from sources: [1], [2], NTSC, PAL, SECAM File links The following pages link to this file: NTSC PAL SÉCAM Categories: GFDL images ... Latin is an ancient Indo-European language. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ... DVD (also known as Digital Versatile Disc or Digital Video Disc) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ... QuickTime is a multimedia technology developed by Apple Computer, capable of handling various formats of digital video, sound, text, animation, music, and immersive panoramic (and sphere panoramic) images. ... MPEG-4 is a standard used primarily to compress audio and video (AV) digital data. ... An analog or analogue signal is any continuously variable signal. ... Bottom view of VHS videotape cassette with magnetic tape exposed Videotape is a means of recording television pictures and accompanying sound onto magnetic tape as opposed to movie film. ... Top view VHS cassette with U.S. 25c coin for scale Bottom view of VHS cassette with magnetic tape exposed The Video Home System, better known by its abbreviation VHS or simply as Video, is a recording and playing standard for video cassette recorders (VCRs), developed by JVC (with some... Sonys Betamax is the 12. ... The Arricam ST, a popular 35 mm film camera currently used on major productions. ... PAL, short for phase-alternating line, phase alternation by line or phase alternation line, is a colour encoding system used in broadcast television systems in large parts of the world. ... NTSC is the analog television system in use in Korea, Japan, United States, Canada and certain other places, mostly in the Americas (see map). ... A video camera can be classified two ways: Professional video cameras, such as those used in television production Camcorders used by amateurs This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... MPEG-4 is a standard used primarily to compress audio and video (AV) digital data. ... A MiniDV tape For other uses, see DV (disambiguation). ... Digital cameras are a remarkable advance in technology. ...

Quality of video essentially depends on the capturing method and storage used. Digital television (DTV) is a relatively recent format with higher quality than earlier television formats and has become a standard for television video. (See List of digital television deployments by country.) Video quality is a characteristic of video passed through a video processing system. ... Digital television (DTV) is a telecommunication system for broadcasting and receiving moving pictures and sound by means of digital signals, in contrast to analog signals in analog (traditional) TV. It uses digital modulation data, which is digitally compressed and requires decoding by a specially designed television set or a standard... The transition to Digital television is a process that follows different paces around the world. ...

3D-video, digital video in three dimensions, premiered at the end of 20th century. Six or eight cameras with realtime depth measurement are typically used to capture 3D-video streams. The format of 3D-video is fixed in MPEG-4 Part 16 Animation Framework eXtension (AFX). This US Postage Stamp celebrates the 3-D movie craze of the 1950s. ... MPEG-4 is a standard used primarily to compress audio and video (AV) digital data. ...

In the UK, Australia, and New Zealand, the term video is often used informally to refer to both video recorders and video cassettes; the meaning is normally clear from the context. U.S. stamp commemorating the VCR. The videocassette recorder (or VCR, more commonly known in the British Isles as the video recorder), is a type of video tape recorder that uses removable videotape cassettes containing magnetic tape to record audio and video from a television broadcast so it can be... Bottom view of VHS videotape cassette with magnetic tape exposed Videotape is a means of recording television pictures and accompanying sound onto magnetic tape as opposed to movie film. ...

Characteristics of video streams

Number of frames per second

Frame rate, the number of still pictures per unit of time of video, ranges from six or eight frames per second (fps) for old mechanical cameras to 120 or more frames per second for new professional cameras. PAL (Europe, Asia, Australia, etc.) and SECAM (France, Russia, parts of Africa etc.) standards specify 25 fps, while NTSC (USA, Canada, Japan, etc.) specifies 29.97 fps. Film is shot at the slower frame rate of 24fps. To achieve the illusion of a moving image, the minimum frame rate is about ten frames per second. PAL, short for phase-alternating line, phase alternation by line or phase alternation line, is a colour encoding system used in broadcast television systems in large parts of the world. ... SÉCAM (Séquentiel couleur à mémoire, French for sequential colour with memory) is an analog color television system first used in France. ... NTSC is the analog television system in use in Korea, Japan, United States, Canada and certain other places, mostly in the Americas (see map). ...

Interlacing

Video can be interlaced or progressive. Interlacing was invented as a way to achieve good visual quality within the limitations of a narrow bandwidth. The horizontal scan lines of each interlaced frame are numbered consecutively and partitioned into two fields: the odd field consisting of the odd-numbered lines and the even field consisting of the even-numbered lines. NTSC, PAL and SECAM are interlaced formats. Abbreviated video resolution specifications often include an i to indicate interlacing. For example, PAL video format is often specified as 576i50, where 576 indicates the vertical line resolution, i indicates interlacing, and 50 indicates 50 fields (half-frames) per second. Interlacing is a method of displaying images on a raster-scanned display device, such as a cathode ray tube (CRT). ... Progressive scan Progressive or non-interlaced scanning is any method for displaying, storing or transmitting moving images in which the lines of each frame are drawn in sequence. ...

In progressive scan systems, each refresh period updates all of the scan lines. The result is a higher perceived resolution and a lack of various artifacts that can make parts of a stationary picture appear to be moving or flashing.

A procedure known as deinterlacing can be used for converting an interlaced stream, such as analog, DVD, or satellite, to be processed by progressive scan devices, such as TFT TV-sets, projectors, and plasma panels. Deinterlacing cannot, however, produce a video quality that is equivalent to true progressive scan source material. Deinterlacing the process of converting interlaced video (a sequence of fields) into a non-interlaced form (a sequence of frames). ... Liquid crystal display television (LCD TV) is, as indicated by its name, a television using LCD technology (generally TFT), as opposed to cathode ray or plasma for its visual output. ... Video quality is a characteristic of video passed through a video processing system. ...

Video resolution

The size of a video image is measured in pixels for digital video or horizontal scan lines for analog video. Standard-definition television (SDTV) is specified as 720/704/640×480i60 for NTSC and 768/720×576i50 for PAL or SECAM resolution. New high-definition televisions (HDTV) are capable of resolutions up to 1920×1080p60, i.e. 1920 pixels per scan line by 1080 scan lines, progressive, at 60 frames per second. Image File history File links Standard_video_res. ... Image File history File links Standard_video_res. ... This example shows an image with a portion greatly enlarged. ... Standard-definition television or SDTV refers to television systems that have a lower resolution than HDTV systems. ... Projection screen in a home theater, displaying a high-definition television image. ...

Video resolution for 3D-video is measured in voxels (volume picture element, representing a value in three dimensional space). For example 512×512×512 voxels resolution, now used for simple 3D-video, can be displayed even on some PDAs. A voxel (a portmanteau of the words volumetric and pixel) is a volume element, representing a value in three dimensional space. ... palmOne Tungsten T5 Personal Digital Assistants (PDAs) are handheld devices that were originally designed as personal organisers, but became much more versatile over the years. ...

Aspect ratio

Aspect ratio describes the dimensions of video screens and video picture elements. The screen aspect ratio of a traditional television screen is 4:3, or 1.33:1. High definition televisions use an aspect ratio of 16:9, or about 1.78:1. The aspect ratio of a full 35 mm film frame with soundtrack (also known as "Academy standard") is around 1.37:1. Download high resolution version (1175x500, 5 KB)Illustration of various aspect ratios. ... Download high resolution version (1175x500, 5 KB)Illustration of various aspect ratios. ... Cinematography, English render of the French cimÃ©matographie, is the discipline of making lighting and camera choices when recording photographic images for the cinema. ... The aspect ratio of an image is its displayed width divided by its height (usually expressed as x:y). For instance, the aspect ratio of a traditional television screen is 4:3, or 1. ...

Pixels on computer monitors are usually square, but pixels used in digital video have non-square aspect ratios, such as those used in the PAL and NTSC variants of the CCIR 601 digital video standard, and the corresponding anamorphic widescreen formats. Digital video is a type of video recording system that works by using a digital, rather than analog, representation of the video signal. ... CCIR 601 is the old name of a standard published by the CCIR (now ITU-R) for encoding interlaced analogue video signals in digital form. ...

Color space and bits per pixel

Color model name describes the video color representation. YIQ is used in NTSC television. It corresponds closely to the YUV scheme used in PAL television and the YDbDr scheme used by SECAM television. Image File history File links Download high resolution version (2048x2048, 144 KB)UV plane of the YUV colour space Image created and released into the public domain by Geoff Martin. ... Image File history File links Download high resolution version (2048x2048, 144 KB)UV plane of the YUV colour space Image created and released into the public domain by Geoff Martin. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Example of U-V color plane, Y value = 0. ... This article or section is in need of attention from an expert on the subject. ...

The number of distinct colours that can be represented by a pixel depends on the number of bits per pixel (bpp). A common way to reduce the number of bits per pixel in digital video is by chroma subsampling (e.g. 4:4:4, 4:2:2, 4:2:0). In digital image processing, chroma subsampling is the use of lower resolution for the colour (chroma) information in an image than for the brightness (intensity or luma) information. ...

Video quality

Video quality can be measured with formal metrics like PSNR or with subjective video quality using expert observation. Video quality is a characteristic of video passed through a video processing system. ... The phrase peak signal-to-noise ratio, often abbreviated PSNR, is an engineering term for the ratio between the maximum value of a signal and the magnitude of background noise. ... Subjective video quality is a subjective characteristic of video quality. ...

The subjective video quality of a video processing system may be evaluated as follows:

Many subjective video quality methods are described in the ITU-T recommendation BT.500. One of the standardized method is the Double Stimulus Impairment Scale (DSIS). In DSIS, each expert views an unimpaired reference video followed by an impaired version of the same video. The expert then rates the impaired video using a scale ranging from "impairments are imperceptible" to "impairments are very annoying". method (from Greek methodos, met hodos literally way across). The word entered English in 1541 via French and Latin. ... Subjective video quality is a subjective characteristic of video quality. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ...

Video compression method (digital only)

A wide variety of methods are used to compress video streams. Video data contains spatial and temporal redundancy, making uncompressed video streams extremely inefficient. Broadly speaking, spatial redundancy is reduced by registering differences between parts of a single frame; this task is known as intraframe compression and is closely related to image compression. Likewise, temporal redundancy can be reduced by registering differences between frames; this task is known as interframe compression, including motion compensation and other techniques. The most common modern standards are MPEG-2, used for DVD and satellite television, and MPEG-4, used for home video. Video compression refers to making a digital video signal use less data, without noticeably reducing the quality of the picture. ... Redundancy in information theory is the number of bits used to transmit a message minus the number of bits of actual information in the message. ... Image compression is the application of data compression on digital images. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... MPEG-2 is the designation for a group of coding and compression standards for Audio and Video (AV), agreed upon by MPEG (Moving Picture Experts Group), and published as the ISO/IEC 13818 international standard. ... DVD (also known as Digital Versatile Disc or Digital Video Disc) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ... Artists impression of a Boeing 601 satellite, as configured for digital television transmission by SES Astra Satellite television is television delivered by way of communications satellites, as compared to conventional terrestrial television and cable television. ... MPEG-4 is a standard used primarily to compress audio and video (AV) digital data. ...

Bit rate (digital only)

Bit rate is a measure of the rate of information content in a video stream. It is quantified using the bit per second (bit/s) unit or Megabits per second (Mbit/s). A higher bit rate allows better video quality. For example VideoCD, with a bit rate of about 1 Mbit/s, is lower quality than DVD, with a bit rate of about 5 Mbit/s. HDTV has a still higher quality, with a bit rate of about 20 Mbit/s. In telecommunications and computing, bit rate (sometimes written bitrate) is the frequency at which bits are passing a given (physical or metaphorical) point. It is quantified using the bit per second (bit/s) unit. ... Video quality is a characteristic of video passed through a video processing system. ...

Variable bit rate (VBR) is a strategy to maximize the visual video quality and minimize the bit rate. On fast motion scenes, a variable bit rate uses more bits than it does on slow motion scenes of similar duration yet achieves a consistent visual quality. For real-time and non-buffered video streaming when the available bandwidth is fixed, e.g. in videoconferencing delivered on channels of fixed bandwidth, a constant bit rate (CBR) must be used. Variable bit rate (VBR) is a term used in telecommunications and computing that relates to sound or video quality. ... Constant bit rate (CBR) is a term used in telecommunications, relating to the quality of service. ...

Stereoscopic

Stereoscopic video requires either two channels — a right channel for the right eye and a left channel for the left eye or two overlayed color coded layers. This left and right layer technique is occasionally used for network broadcast, or recent "anaglyph" releases of 3D movies on DVD. Simple Red/Cyan plastic glasses provide the means to view the images discretely to form a stereoscopic view of the content. New HD DVD and HD Blu-ray disks will greatly improve the 3D effect, in color coded stereo programs. The first commercially available HD players are expected to debut at the 2006 NAB Show in Las Vegas in April. See articles Stereoscopy and 3-D film. HD-DVD disc HD DVD (for High Density Digital Versatile Disc) is a digital optical media format which is being developed as one standard for high-definition DVD. HD DVD is similar to the competing Blu-ray Disc, which also uses the same CD sized (120 mm diameter) optical data... Blu-ray discs Blu-ray Disc is a next-generation optical disc format jointly developed by a group of leading consumer electronics and PC companies called the Blu_ray Disc Association (BDA), which succeeds the Blu_ray Disc Founders (BDF). ... The National Association of Broadcasters (NAB) is the industry group representing the commercial radio stations and television stations of the United States. ... Stereo card image modified for crossed eye viewing View of Manhattan, c. ... This US Postage Stamp celebrates the 3-D movie craze of the 1950s. ...

Video formats

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