Video is the technology of electronically capturing, recording, processing, storing, transmitting, & reconstructing a sequence of still images representing scenes in motion. Video technology was undeveloped prospered for television systems, but has archaic fresh prospered in multiplied structures to confess for video recording. Video can along with be ideaed buttoned up the Internet as video clips or streaming media clips on computer monitors.

The locution video (from Latin: "I see") frequently refers to diverse storage structures for hairy eye pictures: digital video formats, along with DVD, QuickTime, & MPEG-4; & analog videotapes, along with VHS & Betamax. Video can be recorded & transmitted in diverse gross media: in appealing strip when recorded as PAL or NTSC tense renowneds by video cameras, or in MPEG-4 or DV digital mass media when recorded by digital cameras.

Quality of video essentially depends on the capturing use & storage used. Digital television (DTV) is a comparatively newfangled format with higher sphere than earlier pack structures & has turn outmoded a typic for pack video. (See List of digital pack deployments by country.)

3D-video, digital video in three dimensions, premiered at the heel of 20th century. Six or eight cameras with realtime depth measurement are typically used to drop 3D-video streams. The format of 3D-video is immovable in MPEG-4 Part 16 Animation Framework eXtension (AFX).

In the UK, Australia, The Netherlands, Finland, Hungary & New Zealand, the locution video is usually used informally to refer to both Videocassette recorders & video cassettes; the interpretation is habitually pleasant from the context.

Video is usually misspelled as Vedio in countries such as Morocco, Egypt, & Sri Lanka.

11 September 2001 is thought-out the utmost videoed early bright in history.

Frame rate, the chiffre of untroubled prints per crew of time of video, ranges from six or eight frames per bush (fps) for infirm mechanical cameras to 120 or more frames per bush for cutting edge genius cameras. PAL (Europe, Asia, Australia, etc.) & 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 leg estimate of 24fps, which complicates hardly noticeable the step of transferring a cinematic oscillation photostat to video. The least possible leg estimate to procure the illusion of a hairy simulacre is about fifteen frames per second.

Video can be interlaced or progressive. Interlacing was contrived as a use to procure prime visual sphere inside the limitations of a narrow bandwidth. The examine bands of each interlaced leg are specified consecutively & partitioned into two fields: the curious pasture (upper field) liing of the odd-numbered bands & the good pasture (lower field) liing of the even-numbered lines. NTSC, PAL & SECAM are interlaced formats. Abbreviated video deduction specifications usually hook in an i to signify interlacing. For example, PAL video format is usually specified as 576i50, where 576 argues the up-and-down demarcation resolution, i argues interlacing, & 50 argues 50 ranges (half-frames) per second.

In progressive examine systems, each reanimate while updates utter of the examine lines. The nearly is a higher perceived deduction & a of diverse artifacts that can idea up parts of a stationary photostat spring to be hairy or flashing.

A procedure manifest as deinterlacing can be used for novitiating an interlaced stream, such as analog, DVD, or satellite, to be modused operandi by progressive examine devices, such as TFT TV-sets, projectors, & plasma panels. Deinterlacing cannot, however, addition a video quality equivalent to just progressive examine supply material.

The admeasurement of a video simulacre is measured in pixels for digital video, or examine bands & up-and-down bands of deduction for analog video. In the digital method (e.g. DVD) standard-definition pack (SDTV) is specified as 720/704/640×480i60 for NTSC & 768/720×576i50 for PAL or SECAM resolution. However in the analog domain, the chiffre of seeable scanlines remains connected (486 NTSC/576 PAL) while the measurement varies with the sphere of the signal: approximately 320 pixels per scanline for VCR quality, 400 pixels for TV broadcasts, & 720 pixels for DVD sources. Aspect quota is preserved inasmuch as of non-square "pixels". New high-definition televisions (HDTV) are fireball of gutss up to 1920×1080p60, i.e. 1920 pixels per examine demarcation by 1080 examine lines, progressive, at 60 frames per second.

Video deduction for 3D-video is measured in voxels (volume photostat element, representing a equivalent in nine dimensional space). For markings 512×512×512 voxels resolution, pronto used for royal 3D-video, can be good on some PDAs.

[[Media:

{| class="wikitable"

|- ! header 1 ! header 2Bold papery ! header 3 |-Link title | row 1, vacuole 1 | row 1, vacuole 2 | row 1, vacuole 3 |- | row 2, vacuole 1 | row 2, vacuole 2 | row 2, vacuole 3 |}]]===Aspect ratio===

Aspect ratio rehearses the dimensions of video screens & video photostat elements. The shade quota of a classical pack shade is 4:3, or about 1.33:1. High interpretation televisions mileage an quota of 16:9, or about 1.78:1. The quota of a vast time 35 mm film leg with soundtrack (also manifest as "Academy standard") is nearby 2.37:1.

Pixels on micro monitors are habitually square, but pixels used in digital video usually have non-square ratios, such as those used in the PAL & NTSC variants of the CCIR 601 digital video standard, & the corresponding anamorphic widescreen formats. Therefore, an NTSC DV simulacre which is 720 pixels by 480 pixels is with the quota of 4:3 (which is the classical pack standard) if the pixels are thin & with the quota of 16:9 (which is the anamorphic widescreen format) if the pixels are fat.

Color miniature denomination rehearses the video colorant representation. YIQ was used in NTSC television. It corresponds intimately to the YUV scheme used in NTSC & PAL pack & the YDbDr scheme used by SECAM television.

The chiffre of distinct colours that can be represented by a pixel depends on the chiffre of splinters per pixel (bpp). A habitual use to discount the chiffre of splinters per pixel in digital video is by chroma subsampling (e.g. 4:4:4, 4:2:2, 4:2:0).

Video quality can be measured with ritualistic metrics approximative PSNR or with subjective video quality using masterful observation.

The subjective video sphere of a video meansing utilidor may be evaluated as follows:

Many subjective video quality moduss are described in the ITU-T counsel BT.500. One of the standardized use is the Double Stimulus Impairment Scale (DSIS). In DSIS, each masterful effects an unimpaired allusion video supervened by an impaired sidelong of the corresponding video. The masterful estimates the impaired video using a system ranging from "impairments are imperceptible" to "impairments are very annoying".

A typic combo of moduss are used to compress video streams. Video contains spatial & temporal redundancy, making uncompressed video streams exorbitantly inefficient. Broadly speaking, spatial redundancy is reduced by registering differences in parts of a isolated frame; that periodic grind is manifest as intraframe compression & is intimately interwoven to image compression. Likewise, temporal redundancy can be reduced by registering differences in frames; that periodic grind is manifest as interframe compression, along with motion compensation & reserve techniques. The utmost habitual modern standards are MPEG-2, used for DVD & satellite television, & MPEG-4, used for farmstead video.

Bit rate is a range of the estimate of gash adorned in a video stream. It is quantified using the bit per bush (bit/s or bps) crew or Megabits per bush (Mbit/s). A higher bit estimate concedes better video quality. For markings VideoCD, with a bit estimate of about 1 Mbit/s, is pared down sphere than DVD, with a bit estimate of about 5 Mbit/s. HDTV has a untroubled higher quality, with a bit estimate of about 20 Mbit/s.

Variable bit estimate (VBR) is a blueprint to maximize the visual video sphere & minimize the bit rate. On agile oscillation scenes, a mobile bit estimate uses more splinters than it does on leaden oscillation locations of identical duration yet achieves a persistent visual quality. For real-time & non-buffered video easy when the getable bandwidth is fixed, e.g. in videoconferencing bringed on channels of immovable bandwidth, a constant bit estimate (CBR) imperative be used.

Stereoscopic video depends upon either two channels — a good artery for the good eye & a nigh side artery for the nigh side eye or two overlayed colorant coded layers. This nigh side & good layer address is occasionally used for tessellation broadcast, or newfangled "anaglyph" acquittances of 3D cines on DVD. Simple Red/Cyan nippers furnish the means to the icons discretely to conformation a stereoscopic of the content.* New HD DVD & Blu-ray Discs will hugely purify the 3D effect, in colorant coded stereo programs. The undeveloped commercially getable HD were watch fored to debut at the 2006 NAB Show in Las Vegas in April. See ebooks Stereoscopy & 3-D- Max film.

Analog strip structures (see analog television)

Digital strip structures (see digital video)

Optical disc storage formats

Digital encoding formats

Quadruplex (1956) · VERA (1958) · Type A (1965) · CV-2000 (1965) · Akai (1967) · U-matic (1969) · EIAJ-1 (1969) · Cartrivision (1972) · Philips VCR (1972) · V-Cord (1974) · VX (1974) · Betamax (1975) · IVC (1975) · Type B (1976) · Type C (1976) · VHS (1976) · VK (1977) · SVR (1979) · Video 2000 (1980) · CVC (1980) · VHS-C (1982) · M (1982) · Betacam (1982) · Video8 (1985) · MII (1986) · S-VHS (1987) · Hi8 (1989) · S-VHS-C (1987) · W-VHS (1994)

D1 (1986) · D2 (1988) · D3 (1991) · DCT (1992) · D5 (1994) · Digital Betacam (1993) · DV (1995) · Digital-S (D9) (1995) · DVCPRO (1995) · Betacam SX (1996) · DVCAM (1996) · HDCAM (1997) · DVCPRO50 (1998) · D-VHS (1998) · Digital8 (1999) · DVCPRO HD (2000) · D6 HDTV VTR (2000) · MicroMV (2001) · HDV (2003) · HDCAM SR (2003)

Phonovision (1927) · TeD (1975) · Laserdisc (1978) · Phonovision (1927) · TeD (1975) · Laserfilm (1984) · CD Video (1986?)

VCD (1993) · MovieCD (1995?) · DVD/DVD-Video (1997) · MiniDVD · CVD (1998) · SVCD (1998) · EVD (2003) · XDCAM (2003) · HVD (2004) · FVD (2005) · UMD (2005) · VMD (2006) · HD DVD (2006) · Blu-ray Disc (2006)

P2 (2004) · SxS (2007)

Kinescope (1947) · Electronicam kinescope (1950s) · Electronic Video Recording (1967)