|
DCT (videocassette Format)
DCT is a digital recording component video videocassette format developed and introduced by Ampex in 1992. It was based on the D1 format, and unlike the uncompressed recording scheme of D1, it was the first digital videotape format to use data compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compressio .... Like D1 (and D2), it uses a similar cassette loaded with 3/4" (19mm) width tape. One of the models of VCR released for the format was the Ampex DCT-1700D. The type of data compression used by the format, discrete cosine transform (DCT), shares the same acronym as the format, but the meaning is different for the latter (the format's acronym meaning Data Component Technology).Mika Iisakkila, ''Video recording formats'' DST ( Data Storage Technology), a data-only version of D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape could with relative ease record and playback audio, visual, and binary computer data. Magnetic tape revolutionized sound recording and reproduction and broadcasting. It allowed radio, which had always been broadcast live, to be recorded for later or repeated airing. Since the early 1950s, magnetic tape has been used with computers to store large quantities of data and is still used for backup purposes. Magnetic tape begins to degrade after 10–20 years and therefore is not an ideal medium for long-term archival storage. Durability While good for short-term use, magnetic tape is highly prone to disintegration. Depending on the environment, this process may begin after 10–20 years. Over time, magnetic tape made in the 197 ... [...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] |
Helical Scan
Helical scan is a method of recording high-frequency signals on magnetic tape. It is used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. History Earl E Masterson from RCA patented the first helical scan method in 1950 after stealing it from German engineer Eduard Schüller. Eduard Schüller developed an actually working helical scan method of recording in 1953 while working at AEG. With the advent of television broadcasting in Japan in the early 1950s, they saw the need for magnetic television signal recording. Dr. Kenichi Sawazaki developed a prototype helical scan recorder in 1954. Gallery Bcn-scanner-head.jpg, Type B videotape video scanner head Vxa1-drive-nocover-nobezel-front.jpg, rotary head visible in a VXA computer tape drive Vxa1-drive-nocover-top-front.jpg, VXA tape drive, alternate view of rotary head and loading mechanism See also * Type A videotape * 1 inch type B videotape * 1 i ... [...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] |
Ampex
Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe History of television, 1942 to 2000– McFarland, 2003 – , page 286, Chapter 2, footnote 34 "1944 he founded Ampex (the name was created from his initials, AMP, plus "ex" for excellence)" Today, Ampex operates as Ampex Data Systems Corporation, a subsidiary of Delta Information Systems, and consists of two business units. The Silicon Valley unit, known internally as Ampex Data Systems (ADS), manufactures digital data storage systems capable of functioning in harsh environments. The Colorado Springs, Colorado unit, referred to as Ampex Intelligent Systems (AIS), serves as a laboratory and hub for the company's line of industrial control systems, cyber security products and services and its artificial intelligence/machine learning technology. Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Production
Video production is the process of producing video content for video. It is the equivalent of filmmaking, but with video recorded either as analog signals on videotape, digitally in video tape or as computer files stored on optical discs, hard drives, SSDs, magnetic tape or memory cards instead of film stock. There are three stages of video production: pre-production, production (also known as principal photography), and post-production. Pre-production involves all of the planning aspects of the video production process before filming begins. This includes scriptwriting, scheduling, logistics, and other administrative duties. Production is the phase of video production which captures the video content (electronic moving images) and involves filming the subject(s) of the video. Post-production is the action of selectively combining those video clips through video editing into a finished product that tells a story or communicates a message in either a live event setting (live product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Recording
In digital recording, an audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or chroma and luminance values for video. This number stream is saved to a storage device. To play back a digital recording, the numbers are retrieved and converted back into their original analog audio or video forms so that they can be heard or seen. In a properly matched analog-to-digital converter (ADC) and digital-to-analog converter (DAC) pair the analog signal is accurately reconstructed per the constraints of the Nyquist–Shannon sampling theorem dependent on the sampling rate and quantization error dependent on the audio or video bit depth. Because the signal is stored digitally, assuming proper error detection and correction, the recording is not degraded by copying, storage or interference. Timeline *October 3, 1938: British telephone engineer Alec Harley Reeves files at the French Patent Office the fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Component Video
Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Component video can be contrasted with '' composite video'' in which all the video information is combined into a single signal that is used in analog television. Like composite, component-video cables do not carry audio and are often paired with audio cables. When used without any other qualifications, the term ''component video'' usually refers to analog component video with sync on luma (Y) found on analog high-definition televisions and associated equipment from the 1990s through the 2000s when they were largely replaced with HDMI and other all-digital standards. Component video cables and their RCA jack connectors on equipment are normally color-coded red, green and blue, although the signal is not in RGB. YPbPr component video can be los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Videocassette
Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette recorders (VCRs) and camcorders. Videotapes have also been used for storing scientific or medical data, such as the data produced by an electrocardiogram. Because video signals have a very high bandwidth, and stationary heads would require extremely high tape speeds, in most cases, a helical-scan video head rotates against the moving tape to record the data in two dimensions. Tape is a linear method of storing information and thus imposes delays to access a portion of the tape that is not already against the heads. The early 2000s saw the introduction and rise to prominence of high-quality random-access video recording media such as hard disks and flash memory. Since then, videotape has been increasingly relegated to archival and simi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D1 (Sony)
D-1 or 4:2:2 Component Digital is an SMPTE digital recording video standard, introduced in 1986 through efforts by SMPTE engineering committees. It started as a Sony and Bosch - BTS product and was the first major professional digital video format. SMPTE standardized the format within ITU-R 601 (orig. CCIR-601), also known as Rec. 601, which was derived from SMPTE 125M and EBU 3246-E standards. Format D-1 or 4:2:2 D-1 (1986) was a major feat in real time, broadcast quality digital video recording. It stores uncompressed digitized component video, encoded at Y'CbCr 4:2:2 using the CCIR 601 raster format with 8 bits, along with PCM audio tracks as well as timecode on a 3/4 inch (19 mm) videocassette tape (though not to be confused with the ubiquitous 3/4-inch U-Matic/U-Matic SP cassette). The uncompressed component video used enormous bandwidth for its time: 173 Mbit/sec (bit rate). The maximum record time on a D-1 tape is 94 minutes. Because of the uncompromisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding; encoding done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means for mapping data onto a signal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D2 (video Format)
D-2 is a professional digital videocassette format created by Ampex and introduced in 1988 at the NAB Show as a composite video alternative to the component video D-1 format. It garnered Ampex a technical Emmy in 1989. Like D-1, D-2 stores uncompressed digital video on a tape cassette; however, it stores a composite video signal, rather than component video as with D-1. While component video is superior for advanced editing, especially when chroma key effects are used, composite video was more compatible with most analog facilities existing at the time. History Ampex created the first D-2 video machine, the ACR-225 commercial spot player working with Sony, who had done some early research into composite digital video, as a cost-effective solution for TV broadcasters with large investments in composite analog infrastructure such as video routers and switchers, since it could be inserted into existing analog broadcast facilities without extensive redesign or modifications. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
