- T&FHigh-definition video or HD video refers to any video system of higher resolution than standard-definition (SD) video, and most commonly involves display resolutions of 1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i\/1080p).High definition video (prerecorded and broadcast) is defined threefold by:The number of lines in the vertical display resolution. High-definition television (HDTV) resolution is 1,080 or 720 lines. In contrast, regular digital television (DTV) is 480 lines (upon which NTSC is based, 480 visible scanlines out of 525) or 576 lines (upon which PAL\/SECAM are based, 576 visible scanlines out of 625). However, since HD is broadcast digitally, its introduction sometimes coincides with the introduction of DTV. Additionally, current DVD quality is not high-definition, although the high-definition disc systems Blu-ray Disc and the defunct HD DVD are.The scanning system: progressive scanning (p) or interlaced scanning (i). Progressive scanning redraws an image frame (all of its lines) when refreshing each image. Interlaced scanning draws the image field every other line or "odd numbered" lines during the first image refresh operation, and then draws the remaining "even numbered" lines during a second refreshing. Interlaced scanning yields greater image resolution if subject is not moving, but loses up to half of the resolution and suffers "combing" artifacts when subject is moving.The number of frames or fields per second. The 720p60 format is 1,280 × 720 pixels, progressive encoding with 60 frames per second (60 Hz). The 1080i50 format is 1920 × 1080 pixels, interlaced encoding with 50 fields per second. Two interlaced fields formulate a single frame, because the two fields of one frame are temporally shifted. Frame pulldown and segmented frames are special techniques that allow transmitting full frames by means of interlaced video stream.For commercial naming of the product, either the frame rate or the field rate is dropped; e.g., a "1080i television set" label indicates only the image resolution. Often, the rate is inferred from the context, usually assumed to be either 50 or 60, except for 1080p, which denotes 1080p24, 1080p25, and 1080p30, but also 1080p50 and 1080p60.A frame or field rate can also be specified without a resolution. For example 24p means 24 progressive scan frames per second and 50i means 25 interlaced frames per second, consisting of 50 interlaced fields per second. Most HDTV systems support some standard resolutions and frame or field rates. The most common are noted below. High-definition signals require a high-definition television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (1.78:1). The aspect ratio of regular widescreen film shot today is typically 1.85:1 or 2.39:1 (sometimes traditionally quoted at 2.35:1). Standard-definition television (SDTV) has a 4:3 (1.33:1) aspect ratio, although in recent years many broadcasters have transmitted programs "squeezed" horizontally in 16:9 anamorphic format, in hopes that the viewer has a 16:9 set which stretches the image out to normal-looking proportions, or a set which "squishes" the image vertically to present a "letterbox" view of the image, again with correct proportions.
Audio and video glossary. 2014.
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VIDEO\/AUDIO CODEC — T&F A video codec is a device or software that enables video compression and/or decompression for digital video. The compression usually employs lossy data compression. Historically, video was stored as an analog signal on magnetic tape. Around… … Audio and video glossary
Video Quality — WikiV The ability of the public safety agency to use the required video to perform the purpose intended. For example if the purpose of the video is to capture license plates on vehicles in a range of outdoor conditions, video quality is measured… … Audio and video glossary
Video gain (white level, white bar, reference white) — A&V The range of light to dark values of the image which are proportional to the voltage difference between the black and white voltage levels of the video signal. Expressed on the waveform monitor by the voltage level of the whitest whites in… … Audio and video glossary
Video switcher (production switcher, video mixer) — A&V Device that accepts inputs from a variety of video sources and allows the operator to select a particular source to be sent to the switcher s output(s). May also include circuits for video mixing, wiping, keying, and other special effects … Audio and video glossary
video card — TV The PC card that controls the computer s monitor display. Don t confuse the computer s video (VGA, SVGA, Mac monitor and so on) which is non interlaced, with NTSC video. PC cards for DTV are also called capture, overlay or compression cards.… … Audio and video glossary
Video crosspoint module — A&V In video switchers, a circuit board containing video switching crosspoints … Audio and video glossary
Video path — A&V The electronic path within the device that routes and processes the video signals. Video path length refers to the amount of time required for a signal to travel from input to output … Audio and video glossary
Video processing amplifier — A&V A device that stabilizes the composite video signal, regenerates the synchronizing signals, and allows other adjustments to the video signal parameters … Audio and video glossary
Video Blog — VP Often called a Vlog, a Video Blog is a type of video that acts as a visual representation traditional written blogs … Audio and video glossary
Video Editing Workstation — VP An ensemble of digital video editing computers, monitors, postproduction VCRs, DVD recordrs, and other equipment used for video postproduction and production of photomontages … Audio and video glossary
Video On Demand — VP Streaming videos that users view from a website whenever they want, as opposed to a webcast, where the video streams at certain times. Video on demand is often shortened to VOD … Audio and video glossary