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Field Dominance
In video engineering, field dominance refers to the choice of which field of an interlaced video signal is chosen as the point at which video edits or switches occur. There are two main choices for field dominance: odd or even. With odd field dominance the edit or switch occurs at the start of the odd field. With even field dominance the edit or switch occurs at the start of the even field (some equipment, such as vision mixers or switchers allow the field dominance to be set to 'none' which means the switch will occur on the next field boundary after the switch has been pressed). Interlacing divides the frame into two fields, each containing half the number of lines. Each field is scanned in 1/60 second under the 525-line system (or 480i – often incorrectly referred to as NTSC) or 1/50 of a second under the 625-line system (or 576i – often incorrectly referred to as PAL). With interlaced systems there are an odd number of lines in each frame. This means that there is a half lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Engineering
Video is an Electronics, electronic medium for the recording, copying, playback, broadcasting, and display of moving picture, moving image, visual Media (communication), media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems which, in turn, were replaced by flat panel displays of several types. Video systems vary in display resolution, Display aspect ratio, aspect ratio, refresh rate, color capabilities and other qualities. Analog and digital variants exist and can be carried on a variety of media, including radio broadcast, magnetic tape, optical discs, Video file format, computer files, and Streaming media, network streaming. History Analog video Video technology was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) television systems, but several new technologies for video display devices have since been invented. Video was originally excl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field (video)
In video, a field is one of the many still images which are displayed sequentially to create the impression of motion on the screen. Two fields comprise one video frame. When the fields are displayed on a video monitor they are "interlaced" so that the content of one field will be used on all of the odd-numbered lines on the screen and the other field will be displayed on the even lines. Converting fields to a still frame image requires a process called deinterlacing, in which the missing lines are duplicated or interpolated to recreate the information that would have been contained in the discarded field. Since each field contains only half of the information of a full frame, however, deinterlaced images do not have the resolution of a full frame. In order to increase the resolution of video images, therefore, new schemes have been created that capture full-frame images for each frame. Video composed of such frames is called progressive scan video. Video shot with a standard vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interlaced Video
Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This enhances motion perception to the viewer, and reduces flicker by taking advantage of the phi phenomenon. This effectively doubles the time resolution (also called ''temporal resolution'') as compared to non-interlaced footage (for frame rates equal to field rates). Interlaced signals require a display that is natively capable of showing the individual fields in a sequential order. CRT displays and ALiS plasma displays are made for displaying interlaced signals. Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all od ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Edit
Video editing is the manipulation and arrangement of video shots. Video editing is used to structure and present all video information, including films and television shows, video advertisements and video essays. Video editing has been dramatically democratized in recent years by editing software available for personal computers. Editing video can be difficult and tedious, so several technologies have been produced to aid people in this task. Pen based video editing software was developed in order to give people a more intuitive and fast way to edit video. Types of editing Though once the province of expensive machines called video editors, video editing software is now available for personal computers and workstations. Video editing includes cutting segments (trimming), re-sequencing clips, and adding transitions and other special effects. * Linear video editing uses video tape and is edited in a very linear way. Several video clips from different tapes are recorded to one singl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
480i
480i is the video mode used for standard-definition digital television in the Caribbean, Japan, South Korea, Taiwan, Philippines, Laos, Western Sahara, and most of the Americas (with the exception of Argentina, Paraguay, and Uruguay). The ''480'' identifies a vertical resolution of 480 lines, and the ''i'' identifies it as an interlaced resolution. The field rate, which is 60 Hz (or 59.94 Hz when used with NTSC color), is sometimes included when identifying the video mode, i.e. 480i60; another notation, endorsed by both the International Telecommunication Union in BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 480i/30. The other common standard definition digital standard, used in the rest of the world, is 576i. It originated from the need for a standard to digitize analog TV (defined in BT.601) and is now used for digital TV broadcasts and home appliances such as game consoles and DVD disc players. Although related, it should not be confused with the an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplementary references cited in the Reports, and the Petition for adoption of transmission standards for color television before the Federal Communications Commission, n.p., 1953], 17 v. illus., diagrs., tables. 28 cm. LC Control No.:5402138Library of Congress Online Catalog/ref> in 1941. In 1961, it was assigned the designation CCIR System M, System M. In 1953, a second NTSC standard was adopted, which allowed for color television broadcast compatible with the existing stock of black-and-white receivers. It is one of three major color formats for analog television, the others being PAL and SECAM. NTSC color is usually associated with the System M. The only other broadcast television system to use NTSC color was the System J. Since the introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
576i
576i is a standard-definition television, standard-definition digital video mode, originally used for digitizing analog television in most countries of the world where the utility frequency for electric power distribution is 50 Hz. Because of its close association with the legacy color encoding systems, it is often referred to as PAL, PAL/SECAM or SECAM when compared to its 60 Hz (typically, see PAL-M) NTSC-colour-encoded counterpart, 480i. The ''576'' identifies a vertical resolution of 576 lines, and the ''i'' identifies it as an Interlaced video, interlaced resolution. The field rate, which is 50 Hertz, Hz, is sometimes included when identifying the video mode, i.e. 576i50; another notation, endorsed by both the International Telecommunication Union in BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 576i/25. Operation In analogue television, the full Raster scan, raster uses 625 lines, with 49 lines having no image content to allow time for cathode r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Editing
Linear video editing is a video editing post-production process of selecting, arranging and modifying images and sound in a predetermined, ordered sequence. Regardless of whether it was captured by a video camera, tapeless camcorder, or recorded in a television studio on a video tape recorder (VTR) the content must be accessed sequentially. For the most part video editing software has replaced linear editing. In the past, film editing was done in linear fashion, where film reels were literally cut into long strips divided by takes and scenes, and then glued or taped back together to create a logical sequence of film. Linear video editing is more time consuming and highly specialised and tedious work. Still, it is relevant today because of these reasons: * The method is simple and inexpensive. * Mandatory for some jobs: for example if only two sections of video clips are to be joined together in sequence it is often the quickest and easiest way. * If video editors learn linear editin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Framing
In video engineering, color framing refers to the color frame sequence of fields in a composite video signal through which the video frame timing and chrominance subcarrier signal timing—in particular, that of the color burst -- cycle through all possible phase relationships. The exact nature of the color frame sequence depends on the video standard being used. In the case of the three main composite video standards, PAL video has an 8-field (4 frame) color frame sequence, and NTSC and SECAM both have 4-field (2 frame) color frame sequences. Preserving the color framing sequence of video across edits and between channels in video effects was an important issue in early analog composite videotape editing systems, as cuts between different color sequences would cause jumps in subcarrier phase, and mixing two signals of different field dominance would result in color artifacts on the part of the signal that was not in sync with the output color frame sequence. To help prevent thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progressive Segmented Frame
Progressive segmented Frame (PsF, sF, SF) is a scheme designed to acquire, store, modify, and distribute progressive scan video using interlaced equipment. With PsF, a progressive frame is divided into two ''segments'', with the odd lines in one segment and the even lines in the other segment. Technically, the segments are equivalent to interlaced ''fields'', but unlike native interlaced video, there is no motion between the two fields that make up the video frame: both fields represent the same instant in time. This technique allows for a progressive picture to be processed through the same electronic circuitry that is used to store, process and route interlaced video. The term ''progressive segmented frame'' is used predominantly in relation to high-definition video, high definition video. In the world of standard-definition video, which traditionally has been using interlaced scanning, it is also known as ''quasi-interlace'', ''progressive recording'' or ''movie mode''. Other na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Framing
In video engineering, color framing refers to the color frame sequence of fields in a composite video signal through which the video frame timing and chrominance subcarrier signal timing—in particular, that of the color burst -- cycle through all possible phase relationships. The exact nature of the color frame sequence depends on the video standard being used. In the case of the three main composite video standards, PAL video has an 8-field (4 frame) color frame sequence, and NTSC and SECAM both have 4-field (2 frame) color frame sequences. Preserving the color framing sequence of video across edits and between channels in video effects was an important issue in early analog composite videotape editing systems, as cuts between different color sequences would cause jumps in subcarrier phase, and mixing two signals of different field dominance would result in color artifacts on the part of the signal that was not in sync with the output color frame sequence. To help prevent thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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