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TV Card
A TV tuner card is a kind of television tuner that allows television signals to be received by a computer. Most TV tuners also function as video capture cards, allowing them to record television programs onto a hard disk much like the digital video recorder (DVR) does. The interfaces for TV tuner cards are most commonly either PCI bus expansion card or the newer PCI Express (PCIe) bus for many modern cards, but PCMCIA, ExpressCard, or USB devices also exist. In addition, some video cards double as TV tuners, notably the ATI All-In-Wonder series. The card contains a tuner and an analog-to-digital converter (collectively known as the analog front end) along with demodulation and interface logic. Some lower-end cards lack an onboard processor and, like a Winmodem, rely on the system's CPU for demodulation. Types There are many types of tuner cards. Analog tuners Analog television cards output a raw video stream, suitable for real-time viewing but ideally requiring some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Card
A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer monitor. Graphics cards are sometimes called discrete or dedicated graphics cards to emphasize their distinction to integrated graphics. A graphics processing unit that performs the necessary computations is the main component of a graphics card, but the acronym "GPU" is sometimes also used to refer to the graphics card as a whole. Most graphics cards are not limited to simple display output. The graphics processing unit can be used for additional processing, which reduces the load from the central processing unit. Additionally, computing platforms such as OpenCL and CUDA allow using graphics cards for general-purpose computing. Applications of general-purpose computing on graphics cards include AI training, cryptocurrency mining, and molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequencies
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves (radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into electrical condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Picture Experts Group
The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by ISO and IEC that sets standards for media coding, including compression coding of audio, video, graphics, and genomic data; and transmission and file formats for various applications.John Watkinson, ''The MPEG Handbook'', p. 1 Together with JPEG, MPEG is organized under ISO/IEC JTC 1/SC 29 – ''Coding of audio, picture, multimedia and hypermedia information'' (ISO/IEC Joint Technical Committee 1, Subcommittee 29). MPEG formats are used in various multimedia systems. The most well known older MPEG media formats typically use MPEG-1, MPEG-2, and MPEG-4 AVC media coding and MPEG-2 systems transport streams and program streams. Newer systems typically use the MPEG base media file format and dynamic streaming (a.k.a. MPEG-DASH). History MPEG was established in 1988 by the initiative of Dr. Hiroshi Yasuda ( NTT) and Dr. Leonardo Chiariglione (CSELT). Chiariglione was the group' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion JPEG
Motion JPEG (M-JPEG or MJPEG) is a video compression format in which each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image. Originally developed for multimedia PC applications, Motion JPEG enjoys broad client support: most major web browsers and players provide native support, and plug-ins are available for the rest. Software and devices using the M-JPEG standard include web browsers, media players, game consoles, digital cameras, IP cameras, webcams, streaming servers, video cameras, and non-linear video editors. History Motion JPEG was originally developed for multimedia PC applications. Early implementations of MJPEG were generally implemented in Hardware. C-Cube was an early proponent with their CL550 JPEG codec been used in several hardware implementations. It was announced that the NeXTdimension from NeXT would ship with an onboard CL550 to implement MJPEG. This was however later shelved and wasn't included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh II
The Macintosh II is a personal computer designed, manufactured, and sold by Apple Computer from March 1987 to January 1990. Based on the Motorola 68020 32-bit CPU, it is the first Macintosh supporting color graphics. When introduced, a basic system with monitor and 20 MB hard drive cost . With a 13-inch color monitor and 8-bit display card the price was around . This placed it in competition with workstations from Silicon Graphics, Sun Microsystems, and Hewlett-Packard. The Macintosh II was the first computer in the Macintosh line without a built-in display; a monitor rested on top of the case like the IBM Personal Computer and Amiga 1000. It was designed by hardware engineers Michael Dhuey (computer) and Brian Berkeley (monitor) and industrial designer Hartmut Esslinger (case). Eighteen months after its introduction, the Macintosh II was updated with a more powerful CPU and sold as the Macintosh IIx. In early 1989, the more compact Macintosh IIcx was introduced at a price simi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-Video
S-Video (also known as separate video, Y/C, and erroneously Super-Video ) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate channels, achieving higher image quality than composite video which encodes all video information on one channel. It also eliminates several types of visual defects such as dot crawl which commonly occur with composite video. Although it improved over composite video, S-Video has lower color resolution than component video, which is encoded over three channels. The Atari 800 was the first to introduce separate Chroma/Luma output in late 1979. However, S-Video did not get widely adopted until JVC's introduction of the S-VHS (Super-VHS) format in 1987, which is why it is sometimes incorrectly referred to as "Super-Video." Before the shift towards digital video the S-video format was widely used by consumers, but it was rarely used in professiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channels) and the even higher-quality component video (three or more channels). In all of these video formats, audio is carried on a separate connection. Composite video is also known by the initials CVBS for composite video baseband signal or color, video, blanking and sync, or is simply referred to as ''SD video'' for the standard-definition television signal it conveys. There are three dominant variants of composite video signals, corresponding to the analog color system used: NTSC, PAL, and SECAM. Usually composite video is carried by a yellow RCA connector, but other connections are used in professional settings. Signal components A composite video signal combines, on one wire, the video information required to recreate a color picture, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video 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. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Television
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that Noise (electronics), electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes Noise (video), snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below digital cliff, a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Softmodem
A software modem, commonly referred to as a softmodem, is a modem with minimal hardware that uses software running on the host computer, and the computer's resources (especially the central processing unit, random access memory, and sometimes audio processing), in place of the hardware in a conventional modem. Softmodems are also sometimes called winmodems due to limited support for platforms other than Windows. By analogy, a linmodem is a softmodem that can run on Linux. Softmodems are sometimes used as an example of a hard real-time system. The audio signals to be transmitted must be computed on a tight interval (on the order of every 5 or 10 milliseconds); they cannot be computed in advance, and they cannot be late or the receiving modem will lose synchronization. History The first generations of hardware modems (including acoustic couplers) and their protocols used relatively simple modulation techniques such as FSK or ASK at low speeds. Under these conditions, modems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
