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Digital Television In The United States
Digital television in the United States is available via digital terrestrial television (DTT), digital cable, satellite television, and IPTV providers (including those delivered over private networks, and those delivered as over-the-top streaming television services over the public internet). Digital terrestrial television (DTT) uses the ATSC standards, replacing the NTSC standards used for analog television, and offering capabilities such as high definition (HD) signals and digital subchannels. All full-power television stations in the United States were required to shut down their analog signals and transition exclusively to digital broadcasting by June 12, 2009. Class A low-power analog stations were required to transition by September 1, 2015, while all other low-power stations, as well as analog rebroadcasters, were required to transition by July 13, 2021. In November 2017, the FCC approved ATSC 3.0 (Next Gen TV), an updated version of the ATSC standards that supports H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio (commonly 16:9) in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same Bandwidth (signal processing), bandwidth as a single analog channel, and provides many new features that analog television cannot. A digital television transition, transition from analog to digital broadcasting began around 2000. Different digital television broadcasting st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Efficiency Video Coding
High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD, and unlike the primarily 8-bit AVC, HEVC's higher fidelity Main 10 profile has been incorporated into nearly all supporting hardware. While AVC uses the integer discrete cosine transform (DCT) with 4×4 and 8×8 block sizes, HEVC uses both integer DCT and discrete sine transform (DST) with varied block sizes between 4×4 and 32×32. The High Efficiency Image Format (HEIF) is based on HEVC. Concept In most ways, HEVC is an extension of the concepts in H.264/MPEG-4 AVC. Both work by comparing different parts of a fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspect Ratio (image)
The aspect ratio of an image is the ratio of its width to its height. It is expressed as two numbers separated by a colon, in the format width:height. Common aspect ratios are 1.85:1 and 2.39:1 in cinematography, 4:3 and 16:9 in television, and 3:2 in still photography and 1:1: Used for square images, often seen on social media platforms like Instagram, 21:9: An ultrawide aspect ratio popular for gaming and desktop monitors. Some common examples The common film aspect ratios used in cinemas are 1.85:1 and 2.39:1.The 2.39:1 ratio is commonly labeled 2.40:1, e.g., in the American Society of Cinematographers' ''American Cinematographer Manual'' (Many widescreen films before the 1970 Society of Motion Picture and Television Engineers, SMPTE revision used 2.35:1). Two common videography, videographic aspect ratios are 4:3 (1.:1), the universal video format of the 20th century, and 16:9 (1.:1), universal for high-definition television and European digital television. Other cinematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-definition Television
High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it refers to the generation following standard-definition television (SDTV). It is the standard video format used in most broadcasts: Terrestrial television, terrestrial broadcast television, cable television, satellite television. Formats HDTV may be transmitted in various formats: * 720p (): 921,600 pixels * 1080i () interlaced scan: 1,036,800 pixels (≈1.04Mpx). * 1080p () progressive scan: 2,073,600 pixels (≈2.07Mpx). ** Some countries also use a non-standard CTA resolution, such as : 777,600 pixels (≈0.78Mpx) per field or 1,555,200 pixels (≈1.56Mpx) per frame When transmitted at two megapixels per frame, HDTV provides about five times as many pixels as SD (standard-definition television). The increased resolution provides for a cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhanced-definition Television
Enhanced-definition television, or extended-definition television (EDTV) is a Consumer Electronics Association (CEA) marketing shorthand term for certain digital television (DTV) formats and devices. Specifically, this term defines an extension of the standard-definition television (SDTV) format that enables a clearer picture during high-motion scenes compared to previous iterations of SDTV, but not producing images as detailed as high-definition television (HDTV). The term refers to devices capable of displaying 480-line or 576-line signals in progressive scan, commonly referred to as 480p ( NTSC-HQ) and 576p ( PAL/SECAM) respectively, as opposed to interlaced scanning, commonly referred to as 480i (NTSC) or 576i (PAL, SECAM). High-motion is optional for EDTV. In Australia, the 576p resolution standard was used by the Special Broadcasting Service (SBS TV) and Seven Network, being technically considered high-definition. In Japan, the term is associated with improvements to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cable Converter Box
A cable converter box or television converter box is an electronic tuning device that transposes/converts channels from a cable television service to an analog RF signal on a single channel, usually VHF or 4, or to a different output for digital televisions such as HDMI. The device allows a television set that is not "cable ready" to receive cable channels. While later televisions were "cable ready" with a standard converter built-in, the existence of premium television (aka pay per view) and the advent of digital cable have continued the need for various forms of these devices for cable television reception. While not an explicit part of signal conversion, many cable converter boxes include forms of descrambling to manage carrier-controlled access restriction to various channels. Cable-ready televisions and other cable-aware A/V devices such as video recorders can similarly convert cable channels to a regular television set, but these do not include advanced capabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coupon-eligible Converter Box
A coupon-eligible converter box (CECB) was a digital television adapter that met eligibility specifications for subsidy "coupons" from the United States government. The subsidy program was enacted to provide terrestrial television viewers with an affordable way to continue receiving free digital terrestrial television services after the nation's television service transitioned to digital transmission and analog transmissions ceased. The specification was developed by the National Telecommunications and Information Administration (NTIA), with input from the broadcast and consumer electronics industries as well as public interest groups. History Early proposals In March 2005, United States House Commerce Committee chairman Joe Barton of Texas said he would introduce a bill requiring the transition to digital television "sometime in the spring", saying he wanted analog broadcasting to end on December 31, 2006. Included in his plan was a $400–$500 million subsidy for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard-definition Television
Standard-definition television (SDTV; also standard definition or SD) is a television system that uses a resolution that is not considered to be either high or enhanced definition. ''Standard'' refers to offering a similar resolution to the analog broadcast systems used when it was introduced. History and characteristics SDTV 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. Digital SDTV broadcast eliminates the ghosting and noisy images associated with analog systems. However, if the reception has interference or is poor, where the error correction cannot compensate one will encounter various other artifacts such as image freezing, stuttering, or dropouts from missing intra-frames or blockiness from missing macroblocks. The audio encoding is the last to suffer a loss due to the lower bandwidth requirements. Standards that suppor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datacasting
Datacasting (data broadcasting) is the transmission of data over a wide area using radio waves. It typically refers to supplemental information sent by television stations alongside digital terrestrial television (DTT) signals. However, datacasting can also be applied to digital data signals carried on analog TV or radio broadcasts. Overview Datacasting often provides a variety of information such as news, weather forecasting, traffic reporting, stock market updates, and other data that may or may not relate to the broadcast programs. It can also include interactive elements like gaming, shopping, or educational content. An electronic program guide is typically included, though this feature is sometimes considered inherent to the digital broadcast standard. The ATSC, DVB, and ISDB standards support broadband datacasting via Digital Terrestrial Television (DTT), although the specifics of implementation are not always defined. For analog TV, moderate and low bandwid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-dynamic-range Video
High dynamic range (HDR), also known as wide dynamic range, extended dynamic range, or expanded dynamic range, is a signal with a higher dynamic range than usual. The term is often used in discussing the dynamic ranges of images, videos, audio or radio. It may also apply to the means of recording, processing, and reproducing such signals including analog signal, analog and Digital signal (signal processing), digitized signals. Imaging In this context, the term ''high dynamic range'' means there is a large amount of variation in light levels within a scene or an image. The ''dynamic range'' refers to the range of luminosity between the brightest area and the darkest area of that scene or image. (HDRI) refers to the set of imaging technologies and techniques that allow the dynamic range of images or videos to be increased. It covers the acquisition, creation, storage, distribution and display of images and videos. Modern films have often been shot with cameras featuring a highe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame Rate
Frame rate, most commonly expressed in frame/s, or FPS, is typically the frequency (rate) at which consecutive images (Film frame, frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and motion capture systems. In these contexts, frame rate may be used interchangeably with and refresh rate, which are expressed in hertz. Additionally, in the context of computer graphics performance, FPS is the rate at which a system, particularly a GPU, is able to generate frames, and refresh rate is the frequency at which a display shows completed frames. In electronic camera specifications frame rate refers to the maximum possible rate frames could be captured, but in practice, other settings (such as exposure time) may reduce the actual frequency to a lower number than the frame rate. Human vision The temporal sensitivity and resolution of human vision varies depending on the type and characteristics of visual stimulus, and it differs betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
