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104-439: MPEG-2 is widely used as the format of digital television signals that are broadcast by terrestrial (over-the-air), cable , and direct broadcast satellite TV systems. It also specifies the format of movies and other programs that are distributed on DVD and similar discs. TV stations , TV receivers , DVD players, and other equipment are often designed to this standard. MPEG-2 was the second of several standards developed by

208-552: A 16:9 aspect ratio. HDTV cannot be transmitted over analog television channels because of channel capacity issues. SDTV, by comparison, may use one of several different formats taking the form of various aspect ratios depending on the technology used in the country of broadcast. NTSC can deliver a 640 × 480 resolution in 4:3 and 854 × 480 in 16:9 , while PAL can give 768 × 576 in 4:3 and 1024 × 576 in 16:9 . However, broadcasters may choose to reduce these resolutions to reduce bit rate (e.g., many DVB-T channels in

312-502: A 1990 FIFA World Cup broadcast in March 1990. An American company, General Instrument , also demonstrated the feasibility of a digital television signal in 1990. This led to the FCC being persuaded to delay its decision on an advanced television (ATV) standard until a digitally based standard could be developed. When it became evident that a digital standard might be achieved in March 1990,

416-402: A scattering effect as the digital processing dithers and is unable to consistently allocate a value of either absolute black or the next step up the greyscale. Changes in signal reception from factors such as degrading antenna connections or changing weather conditions may gradually reduce the quality of analog TV. The nature of digital TV results in a perfectly decodable video initially, until

520-649: A standard-definition television (SDTV) signal, and over 1  Gbit/s for high-definition television (HDTV). In the mid-1980s, Toshiba released a television set with digital capabilities, using integrated circuit chips such as a microprocessor to convert analog television broadcast signals to digital video signals, enabling features such as freezing pictures and showing two channels at once . In 1986, Sony and NEC Home Electronics announced their own similar TV sets with digital video capabilities. However, they still relied on analog TV broadcast signals, with true digital TV broadcasts not yet being available at

624-429: A subwoofer bass channel, producing broadcasts similar in quality to movie theaters and DVDs. Digital TV signals require less transmission power than analog TV signals to be broadcast and received satisfactorily. DTV images have some picture defects that are not present on analog television or motion picture cinema, because of present-day limitations of bit rate and compression algorithms such as MPEG-2 . This defect

728-540: A TV set in the following year. The digital television transition, migration to high-definition television receivers and the replacement of CRTs with flat screens are all factors in the increasing number of discarded analog CRT-based television receivers. In 2009, an estimated 99 million analog TV receivers were sitting unused in homes in the US alone and, while some obsolete receivers are being retrofitted with converters, many more are simply dumped in landfills where they represent

832-535: A consortium of electronics and telecommunications companies that assembled to develop a specification for what is now known as HDTV . The standard is now administered by the Advanced Television Systems Committee . It includes a number of patented elements, and licensing is required for devices that use these parts of the standard. Key among these is the 8VSB modulation system used for over-the-air broadcasts. ATSC 1.0 technology

936-610: A maximum possible MPEG-2 bitrate of 10.08 Mbit/s (7 Mbit/s typical) allowed in the DVD standard and 48 Mbit/s (36 Mbit/s typical) allowed in the Blu-ray disc standard. Although the ATSC A/53 standard limits MPEG-2 transmission to the formats listed below (with integer frame rates paired with 1000/1001-rate versions), the U.S. Federal Communications Commission declined to mandate that television stations obey this part of

1040-436: A more efficient means of converting filmed programming into digital formats. For their part, the consumer electronics industry and broadcasters argued that interlaced scanning was the only technology that could transmit the highest quality pictures then (and currently) feasible, i.e., 1,080 lines per picture and 1,920 pixels per line. Broadcasters also favored interlaced scanning because their vast archive of interlaced programming

1144-529: A private patent licensing organization, had acquired rights from over 20 corporations and one university to license a patent pool of approximately 640 worldwide patents, which it claimed were "essential" to use of MPEG-2 technology. The patent holders included Sony , Mitsubishi Electric , Fujitsu , Panasonic , Scientific Atlanta , Columbia University , Philips , General Instrument , Canon , Hitachi , JVC Kenwood , LG Electronics , NTT , Samsung , Sanyo , Sharp and Toshiba . Where Software patentability

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1248-451: A recent proposal from Thomson /Micronas; all of these systems have been submitted as candidates for a new ATSC standard, ATSC-M/H . After one year of standardization, the solution merged between Samsung's AVSB and LGE's MPH technology has been adopted and would have been deployed in 2009. This is in addition to other standards like the now-defunct MediaFLO , and worldwide open standards such as DVB-H and T-DMB . Like DVB-H and ISDB 1seg ,

1352-473: A similar benefit. In spite of ATSC's fixed transmission mode, it is still a robust signal under various conditions. 8VSB was chosen over COFDM in part because many areas are rural and have a much lower population density , thereby requiring larger transmitters and resulting in large fringe areas. In these areas, 8VSB was shown to perform better than other systems. COFDM is used in both DVB-T and ISDB-T, and for 1seg , as well as DVB-H and HD Radio in

1456-680: A single 6  MHz TV channel . ATSC standards are marked A/ x ( x is the standard number) and can be downloaded for free from the ATSC's website at ATSC.org . ATSC Standard A/53, which implemented the system developed by the Grand Alliance, was published in 1995; the standard was adopted by the Federal Communications Commission in the United States in 1996. It was revised in 2009. ATSC Standard A/72

1560-467: A single HDTV feed or multiple lower-resolution feeds is often referred to as distributing one's bit budget or multicasting. This can sometimes be arranged automatically, using a statistical multiplexer . With some implementations, image resolution may be less directly limited by bandwidth; for example in DVB-T , broadcasters can choose from several different modulation schemes, giving them the option to reduce

1664-410: A single frame often results in black boxes in several subsequent frames, making viewing difficult. For remote locations, distant channels that, as analog signals, were previously usable in a snowy and degraded state may, as digital signals, be perfectly decodable or may become completely unavailable. The use of higher frequencies add to these problems, especially in cases where a clear line-of-sight from

1768-462: A sixth channel for low-frequency effects (the so-called "5.1" configuration). In contrast, Japanese ISDB HDTV broadcasts use MPEG's Advanced Audio Coding (AAC) as the audio codec, which also allows 5.1 audio output. DVB (see below ) allows both. MPEG-2 audio was a contender for the ATSC standard during the DTV " Grand Alliance " shootout, but lost out to Dolby AC-3 . The Grand Alliance issued

1872-426: A source of toxic metals such as lead as well as lesser amounts of materials such as barium , cadmium and chromium . ATSC Advanced Television Systems Committee ( ATSC ) standards are an international set of standards for broadcast and digital television transmission over terrestrial, cable and satellite networks. It is largely a replacement for the analog NTSC standard and, like that standard,

1976-400: A standard-definition (SDTV) digital signal instead of an HDTV signal, because current convention allows the bandwidth of a DTV channel (or " multiplex ") to be subdivided into multiple digital subchannels , (similar to what most FM radio stations offer with HD Radio ), providing multiple feeds of entirely different television programming on the same channel. This ability to provide either

2080-531: A statement finding the MPEG-2 system to be "essentially equivalent" to Dolby, but only after the Dolby selection had been made. Later, a story emerged that MIT had entered into an agreement with Dolby whereupon the university would be awarded a large sum of money if the MPEG-2 system was rejected. Dolby also offered an incentive for Zenith to switch their vote (which they did); however, it is unknown whether they accepted

2184-502: A terrestrial transmitter in range of their antenna. Other delivery methods include digital cable and digital satellite . In some countries where transmissions of TV signals are normally achieved by microwaves , digital multichannel multipoint distribution service is used. Other standards, such as digital multimedia broadcasting (DMB) and digital video broadcasting - handheld (DVB-H), have been devised to allow handheld devices such as mobile phones to receive TV signals. Another way

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2288-512: Is Internet Protocol television (IPTV), which is the delivery of TV over a computer network. Finally, an alternative way is to receive digital TV signals via the open Internet ( Internet television ), whether from a central streaming service or a P2P (peer-to-peer) system. Some signals are protected by encryption and backed up with the force of law under the WIPO Copyright Treaty and national legislation implementing it, such as

2392-440: Is a crucial regulatory tool for controlling the placement and power levels of stations. Digital TV is more tolerant of interference than analog TV. People can interact with a DTV system in various ways. One can, for example, browse the electronic program guide . Modern DTV systems sometimes use a return path providing feedback from the end user to the broadcaster. This is possible over cable TV or through an Internet connection but

2496-415: Is a media container format. It may contain a number of streams of audio or video content multiplexed within the transport stream. Transport streams are designed with synchronization and recovery in mind for potentially lossy distribution (such as over-the-air ATSC broadcast) in order to continue a media stream with minimal interruption in the face of data loss in transmission. When an over-the-air ATSC signal

2600-438: Is actually encoded with 1920×1088 pixel frames, but the last eight lines are discarded prior to display. This is due to a restriction of the MPEG-2 video format, which requires the height of the picture in luma samples (i.e. pixels) to be divisible by 16. The lower resolutions can operate either in progressive scan or interlaced mode, but not the largest picture sizes. The 1080-line system does not support progressive images at

2704-469: Is backwards-compatible with MPEG-1, allowing MPEG-1 audio decoders to decode the two main stereo components of the presentation. This extension is called MPEG Multichannel or MPEG-2 BC (backwards-compatible). MPEG-2 Part 3 also defines additional bit rates and sampling rates for MPEG-1 Audio Layers I, II, and III. This extension is known as MPEG-2 LSF (low sampling frequencies), since the new sampling rates are one-half multiples (16, 22.05 and 24 kHz) of

2808-459: Is captured to a file via hardware/software the resulting file is often in a .TS file format. ATSC signals are designed to use the same 6 MHz bandwidth as analog NTSC television channels (the interference requirements of A/53 DTV standards with adjacent NTSC or other DTV channels are very strict). Once the digital video and audio signals have been compressed and multiplexed, the transport stream can be modulated in different ways depending on

2912-569: Is common for there to be a single high-definition signal and several standard-definition signals carried on a single 6 MHz (former NTSC) channel allocation. The high-definition television standards defined by the ATSC produce widescreen 16:9 images up to 1920×1080 pixels in size – more than six times the display resolution of the earlier standard. However, many different image sizes are also supported. The reduced bandwidth requirements of lower-resolution images allow up to six standard-definition "subchannels" to be broadcast on

3016-503: Is in some ways less complicated than its predecessor, MPEG-1 Part 3 Audio Layer 3 , in that it does not have the hybrid filter bank. It supports from 1 to 48 channels at sampling rates of 8 to 96 kHz, with multichannel, multilingual, and multiprogram capabilities. AAC is also defined in MPEG-4 Part 3 . MPEG-2 standards are published as "Parts". Each part covers a certain aspect of the whole specification. MPEG-2 evolved out of

3120-692: Is more prone to electromagnetic interference from engines and rapidly changing multipath conditions. ATSC 2.0 was a planned major new revision of the standard which would have been backward compatible with ATSC 1.0. The standard was to have allowed interactive and hybrid television technologies by connecting the TV with the Internet services and allowing interactive elements into the broadcast stream. Other features were to have included advanced video compression, audience measurement, targeted advertising , enhanced programming guides, video on demand services, and

3224-474: Is more susceptible to changes in radio propagation conditions than DVB-T and ISDB-T . It also lacks true hierarchical modulation , which would allow the SDTV part of an HDTV signal (or the audio portion of a television program) to be received uninterrupted even in fringe areas where signal strength is low. For this reason, an additional modulation mode, enhanced-VSB ( E-VSB ) has been introduced, allowing for

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3328-498: Is not possible with a standard antenna alone. Some of these systems support video on demand using a communication channel localized to a neighborhood rather than a city (terrestrial) or an even larger area (satellite). 1seg (1-segment) is a special form of ISDB . Each channel is further divided into 13 segments. Twelve are allocated for HDTV and the other for narrow-band receivers such as mobile televisions and cell phones . DTV has several advantages over analog television ,

3432-634: Is not readily compatible with a progressive format. DirecTV in the US launched the first commercial digital satellite platform in May 1994, using the Digital Satellite System (DSS) standard. Digital cable broadcasts were tested and launched in the US in 1996 by TCI and Time Warner . The first digital terrestrial platform was launched in November 1998 as ONdigital in the UK, using

3536-451: Is only used by TV networks . Very few teleports outside the U.S. support the ATSC satellite transmission standard, but teleport support for the standard is improving. The ATSC satellite transmission system is not used for direct-broadcast satellite systems; in the U.S. and Canada these have long used either DVB-S (in standard or modified form) or a proprietary system such as DSS or DigiCipher 2 . [REDACTED] ATSC coexists with

3640-507: Is sometimes referred to as mosquito noise . Because of the way the human visual system works, defects in an image that are localized to particular features of the image or that come and go are more perceptible than defects that are uniform and constant. However, the DTV system is designed to take advantage of other limitations of the human visual system to help mask these flaws, e.g., by allowing more compression artifacts during fast motion where

3744-429: Is supported, Blu-ray does not support MPEG-2 audio (parts 3 and 7). Additionally, the container format used on Blu-ray discs is an MPEG-2 transport stream, regardless of which audio and video codecs are used. As of January 3, 2024, MPEG-2 patents have expired worldwide, with the exception of only Malaysia, where the last patent is expected to expire in 2035. The last US patent expired on February 23, 2018. MPEG LA ,

3848-440: Is the format used in computers, scans lines in sequences, from top to bottom. The computer industry argued that progressive scanning is superior because it does not flicker in the manner of interlaced scanning. It also argued that progressive scanning enables easier connections with the Internet and is more cheaply converted to interlaced formats than vice versa. The film industry also supported progressive scanning because it offers

3952-457: Is the modulation scheme used on the cable: cable operators in the U.S. (and to a lesser extent Canada) can determine their own method of modulation for their plants. Multiple standards bodies exist in the industry: the SCTE defined 256-QAM as a modulation scheme for cable in a cable industry standard, ANSI/SCTE 07 2006: Digital Transmission Standard For Cable Television Archived July 5, 2010, at

4056-456: Is transmitted, and MPEG-2 metadata instructs the decoder to interlace these fields and perform 3:2 pulldown before display, as in soft telecine . The ATSC specification also allows 1080p30 and 1080p24 MPEG-2 sequences, however they are not used in practice, because broadcasters want to be able to switch between 60 Hz interlaced (news), 30 Hz progressive or PsF (soap operas), and 24 Hz progressive (prime-time) content without ending

4160-482: Is upheld and patents have not expired (only Malaysia), the use of MPEG-2 requires the payment of licensing fees to the patent holders. Other patents were licensed by Audio MPEG, Inc. The development of the standard itself took less time than the patent negotiations. Patent pooling between essential and peripheral patent holders in the MPEG-2 pool was the subject of a study by the University of Wisconsin. According to

4264-588: Is used in the Netflix VMAF video quality monitoring system. Quantising effects can create contours—rather than smooth gradations—on areas with small graduations in amplitude. Typically, a very flat scene, such as a cloudless sky, will exhibit visible steps across its expanse, often appearing as concentric circles or ellipses. This is known as color banding . Similar effects can be seen in very dark scenes, where true black backgrounds are overlaid by dark gray areas. These transitions may be smooth, or may show

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4368-582: Is used mostly in the United States , Mexico , Canada , South Korea and Trinidad & Tobago . Several former NTSC users, such as Japan , have not used ATSC during their digital television transition , because they adopted other systems such as ISDB developed by Japan, and DVB developed in Europe, for example. The ATSC standards were developed in the early 1990s by the Grand Alliance ,

4472-426: Is used on Blu-ray discs, AVCHD on re-writable DVDs and HDV on compact flash cards. Program stream files include VOB on DVDs and Enhanced VOB on the short lived HD DVD . The standard MPEG-2 transport stream contains packets of 188 bytes. M2TS prepends each packet with 4 bytes containing a 2-bit copy permission indicator and 30-bit timestamp. ISO authorized the " SMPTE Registration Authority, LLC" as

4576-520: The DVB standard: Allowed resolutions for SDTV : For HDTV: The ATSC A/53 standard used in the United States, uses MPEG-2 video at the Main Profile @ High Level (MP@HL), with additional restrictions such as the maximum bitrate of 19.39 Mbit/s for broadcast television and 38.8 Mbit/s for cable television, 4:2:0 chroma subsampling format, and mandatory colorimetry information. ATSC allows

4680-501: The DVB-T standard, and with ISDB-T . A similar standard called ADTB-T was developed for use as part of China 's new DMB-T/H dual standard. While China has officially chosen a dual standard, there is no requirement that a receiver work with both standards and there is no support for the ADTB modulation from broadcasters or equipment and receiver manufacturers. For compatibility with material from various regions and sources, ATSC supports

4784-780: The DVB-T standard. Digital television supports many different picture formats defined by the broadcast television systems which are a combination of size and aspect ratio (width to height ratio). With digital terrestrial television (DTT) broadcasting, the range of formats can be broadly divided into two categories: high-definition television (HDTV) for the transmission of high-definition video and standard-definition television (SDTV). These terms by themselves are not very precise and many subtle intermediate cases exist. One of several different HDTV formats that can be transmitted over DTV is: 1280 × 720 pixels in progressive scan mode (abbreviated 720p ) or 1920 × 1080 pixels in interlaced video mode ( 1080i ). Each of these uses

4888-665: The EIA-708 standard for digital closed captioning , leading to variations in implementation. ATSC replaced much of the analog NTSC television system in the United States on June 12, 2009, on August 31, 2011 in Canada , on December 31, 2012 in South Korea , and on December 31, 2015 in Mexico . Broadcasters who used ATSC and wanted to retain an analog signal were temporarily forced to broadcast on two separate channels, as

4992-634: The Federal Communications Commission requires cable operators in the United States to carry the analog or digital transmission of a terrestrial broadcaster (but not both), when so requested by the broadcaster (the " must-carry rule"). The Canadian Radio-television and Telecommunications Commission in Canada does not have similar rules in force with respect to carrying ATSC signals. However, cable operators have still been slow to add ATSC channels to their lineups for legal, regulatory, and plant & equipment related reasons. One key technical and regulatory issue

5096-475: The Wayback Machine . Consequently, most U.S. and Canadian cable operators seeking additional capacity on the cable system have moved to 256-QAM from the 64-QAM modulation used in their plant, in preference to the 16VSB standard originally proposed by ATSC. Over time 256-QAM is expected to be included in the ATSC standard. There is also a standard for transmitting ATSC via satellite; however, this

5200-692: The 1080i60 MPEG-2 sequence. The 1080-line formats are encoded with 1920 × 1088 pixel luma matrices and 960 × 540 chroma matrices, but the last 8 lines are discarded by the MPEG-2 decoding and display process. In July 2008, ATSC was updated to support the ITU-T H.264 video codec. The new standard is split in two parts: The new standards support 1080p at 50, 59.94 and 60 frames per second; such frame rates require H.264/AVC High Profile Level 4.2 , while standard HDTV frame rates only require Levels 3.2 and 4, and SDTV frame rates require Levels 3 and 3.1. The file extension ".TS" stands for "transport stream", which

5304-505: The 480i video format used in the NTSC analog system (480 lines, approximately 60 fields or 30 frames per second), 576i formats used in most PAL regions (576 lines, 50 fields or 25 frames per second), and 24 frames-per-second formats used in film. While the ATSC system has been criticized as being complicated and expensive to implement and use, both broadcasting and receiving equipment are now comparable in cost with that of DVB. The ATSC signal

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5408-404: The ATSC system requires the use of an entire separate channel. Channel numbers in ATSC do not correspond to RF frequency ranges, as they did with analog television . Instead, virtual channels , sent as part of the metadata along with the program(s), allow channel numbers to be remapped from their physical RF channel to any other number 1 to 99, so that ATSC stations can either be associated with

5512-931: The ATSC's standard. In theory, television stations in the U.S. are free to choose any resolution, aspect ratio, and frame/field rate, within the limits of Main Profile @ High Level. Many stations do go outside the bounds of the ATSC specification by using other resolutions – for example, 352 x 480 or 720 x 480. " EDTV " displays can reproduce progressive scan content and frequently have a 16:9 wide screen format. Such resolutions are 704×480 or 720×480 in NTSC and 720×576 in PAL, allowing 60 progressive frames per second in NTSC or 50 in PAL. ATSC also supports PAL frame rates and resolutions which are defined in ATSC A/63 standard. The ATSC A/53 specification imposes certain constraints on MPEG-2 video stream: The ATSC specification and MPEG-2 allow

5616-561: The Bootstrap component of ATSC 3.0 (System Discovery and Signalling) was upgraded from candidate standard to finalized standard. On June 29, 2016, NBC affiliate WRAL-TV in Raleigh, North Carolina , a station known for its pioneering roles in testing the original DTV standards, launched an experimental ATSC 3.0 channel carrying the station's programming in 1080p, as well as a 4K demo loop. The following organizations held patents for

5720-473: The FCC took several important actions. First, the Commission declared that the new TV standard must be more than an enhanced analog signal , but be able to provide a genuine HDTV signal with at least twice the resolution of existing television images. Then, to ensure that viewers who did not wish to buy a new digital television set could continue to receive conventional television broadcasts, it dictated that

5824-454: The FCC's final standard. This outcome resulted from a dispute between the consumer electronics industry (joined by some broadcasters) and the computer industry (joined by the film industry and some public interest groups) over which of the two scanning processes— interlaced or progressive —is superior. Interlaced scanning, which is used in televisions worldwide, scans even-numbered lines first, then odd-numbered ones. Progressive scanning, which

5928-448: The MPEG-2 licensing agreement any use of MPEG-2 technology in countries with active patents (Malaysia) is subject to royalties . MPEG-2 encoders and decoders are subject to $ 0.35 per unit. Also, any packaged medium (DVDs/Data Streams) is subject to licence fees according to length of recording/broadcast. The royalties were previously priced higher but were lowered at several points, most recently on January 1, 2018. An earlier criticism of

6032-469: The MPEG-2 patent pool was that even though the number of patents had decreased from 1,048 to 416 by June 2013 the license fee had not decreased with the expiration rate of MPEG-2 patents. The following organizations have held patents for MPEG-2, as listed at MPEG LA . See also List of United States MPEG-2 patents . Digital television Digital television ( DTV ) is the transmission of television signals using digital encoding, in contrast to

6136-712: The Moving Pictures Expert Group ( MPEG ) and is an international standard ( ISO / IEC 13818 , titled Information technology — Generic coding of moving pictures and associated audio information ). Parts 1 and 2 of MPEG-2 were developed in a collaboration with ITU-T , and they have a respective catalog number in the ITU-T Recommendation Series. While MPEG-2 is the core of most digital television and DVD formats, it does not completely specify them. Regional institutions can adapt it to their needs by restricting and augmenting aspects of

6240-646: The UK use a horizontal resolution of 544 or 704 pixels per line). Each commercial broadcasting terrestrial television DTV channel in North America is allocated enough bandwidth to broadcast up to 19 megabits per second. However, the broadcaster does not need to use this entire bandwidth for just one broadcast channel. Instead, the broadcast can use Program and System Information Protocol and subdivide across several video subchannels (a.k.a. feeds) of varying quality and compression rates, including non-video datacasting services. A broadcaster may opt to use

6344-594: The US Digital Millennium Copyright Act . Access to encrypted channels can be controlled by a removable card, for example via the Common Interface or CableCard . Digital television signals must not interfere with each other and they must also coexist with analog television until it is phased out. The following table gives allowable signal-to-noise and signal-to-interference ratios for various interference scenarios. This table

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6448-412: The United States and elsewhere. The DVD-Video standard uses MPEG-2 video, but imposes some restrictions: HDV is a format for recording and playback of high-definition MPEG-2 video on a DV cassette tape. MOD and TOD are recording formats for use in consumer digital file-based camcorders. XDCAM is a professional file-based video recording format. Application-specific restrictions on MPEG-2 video in

6552-870: The United States. In metropolitan areas , where population density is highest, COFDM is said to be better at handling multipath propagation . While ATSC is also incapable of true single-frequency network (SFN) operation, the distributed transmission mode, using multiple synchronized on-channel transmitters, has been shown to improve reception under similar conditions. Thus, it may not require more spectrum allocation than DVB-T using SFNs. A comparison study found that ISDB-T and DVB-T performed similarly, and that both were outperformed by DVB-T2 . Mobile reception of digital stations using ATSC has, until 2008, been difficult to impossible, especially when moving at vehicular speeds. To overcome this, there are several proposed systems that report improved mobile reception: Samsung / Rhode & Schwarz 's A-VSB , Harris / LG 's MPH, and

6656-465: The ability to store information on new receivers, including Non-realtime (NRT) content. However, ATSC 2.0 was never actually launched, as it was essentially outdated before it could be launched. All of the changes that were a part of the ATSC 2.0 revision were adopted into ATSC 3.0. ATSC 3.0 will provide even more services to the viewer and increased bandwidth efficiency and compression performance, which requires breaking backwards compatibility with

6760-504: The characteristics of the underlying private data. MPEG-2 Part 2 (ISO/IEC 13818-2 and ITU-T Rec. H.262), titled Video , is similar to the previous MPEG-1 Part 2 standard, but adds support for interlaced video , the format used by analog broadcast TV systems. MPEG-2 video is not optimized for low bit rates , especially less than 1 Mbit/s at standard-definition resolutions. All standards-compliant MPEG-2 Video decoders are fully capable of playing back MPEG-1 Video streams conforming to

6864-475: The constrained parameters bitstream (CPB) limits. With some enhancements, MPEG-2 Video and Systems are also used in some HDTV transmission systems, and is the standard format for over-the-air ATSC digital television. MPEG-2 introduces new audio encoding methods compared to MPEG-1: MPEG-2 Part 3 (ISO/IEC 13818-3), titled Audio , enhances MPEG-1 's audio by allowing the coding of audio programs with more than two channels , up to 5.1 multichannel. This method

6968-511: The current version. On November 17, 2017, the FCC voted 3–2 in favor of authorizing voluntary deployments of ATSC 3.0, and issued a Report and Order to that effect. ATSC 3.0 broadcasts and receivers are expected to emerge within the next decade. LG Electronics tested the standard with 4K on February 23, 2016. With the test considered a success, South Korea announced that ATSC 3.0 broadcasts would start in February 2017. On March 28, 2016,

7072-528: The decoder to interlace them and perform 3:2 pulldown before display. This allows broadcasters to switch between 60 Hz interlaced (news, soap operas) and 24 Hz progressive (prime-time) content without ending the MPEG-2 sequence and introducing several seconds of delay as the TV switches formats. This is the reason why 1080p30 and 1080p24 sequences allowed by the ATSC specification are not used in practice. The 1080-line formats are encoded with 1920 × 1088 pixel luma matrices and 960 × 540 chroma matrices, but

7176-414: The digital signals. In the United States, a government-sponsored coupon was available to offset the cost of an external converter box. The digital television transition began around the late 1990s and has been completed on a country-by-country basis in most parts of the world. Prior to the conversion to digital TV, analog television broadcast audio for TV channels on a separate FM carrier signal from

7280-458: 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

7384-525: The early 1990s. In the mid-1980s, as Japanese consumer electronics firms forged ahead with the development of HDTV technology, and as the MUSE analog format was proposed by Japan's public broadcaster NHK as a worldwide standard. Japanese advancements were seen as pacesetters that threatened to eclipse US electronics companies. Until June 1990, the Japanese MUSE standard—based on an analog system—was

7488-573: The end of the stream may not be identified, such as radio frequency , cable and linear recording mediums, examples of which include ATSC / DVB / ISDB / SBTVD broadcasting, and HDV recording on tape. The other is the program stream , an extended version of the MPEG-1 container format with less overhead than transport stream . Program stream is designed for random access storage mediums such as hard disk drives , optical discs and flash memory . Transport stream file formats include M2TS , which

7592-482: The eye cannot track and resolve them as easily and, conversely, minimizing artifacts in still backgrounds that, because time allows, may be closely examined in a scene. Broadcast, cable, satellite and Internet DTV operators control the picture quality of television signal encoders using sophisticated, neuroscience-based algorithms, such as the structural similarity index measure (SSIM) video quality measurement tool. Another tool called visual information fidelity (VIF),

7696-552: The first MPEG-2 SAVI (System/Audio/Video) decoder in 1995. .mpg, .mpeg, .m2v, .mp2, . mp3 are some of a number of filename extensions used for MPEG-1 or MPEG-2 audio and video file formats. File extension MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III ) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in

7800-450: The following video resolutions, aspect ratios, and frame/field rates: ATSC standard A/63 defines additional resolutions and aspect rates for 50 Hz (PAL) signal. The ATSC specification and MPEG-2 allow the use of progressive frames, even within an interlaced video sequence. For example, a station that transmits 1080i60 video sequence can use a coding method where those 60 fields are coded with 24 progressive frames and metadata instructs

7904-526: The front-runner among the more than 23 different technical concepts under consideration. Between 1988 and 1991, several European organizations were working on DCT -based digital video coding standards for both SDTV and HDTV. The EU 256 project by the CMTT and ETSI , along with research by Italian broadcaster RAI , developed a DCT video codec that broadcast SDTV at 34 Mbit/s and near-studio-quality HDTV at about 70–140 Mbit/s . RAI demonstrated this with

8008-436: The highest frame rates of 50, 59.94 or 60 frames per second, because such technology was seen as too advanced at the time. The standard also requires 720-line video be progressive scan, since that provides better picture quality than interlaced scan at a given frame rate, and there was no legacy use of interlaced scan for that format. The result is that the combination of maximum frame rate and picture size results in approximately

8112-425: The image and sound, although the program material may still be watchable. With digital television, because of the cliff effect , reception of the digital signal must be very nearly complete; otherwise, neither audio nor video will be usable. Analog TV began with monophonic sound and later developed multichannel television sound with two independent audio signal channels. DTV allows up to 5 audio signal channels plus

8216-437: The last 8 lines are discarded by the MPEG-2 decoding and display process. ATSC A/72 is the newest revision of ATSC standards for digital television, which allows the use of H.264/AVC video coding format and 1080p60 signal. MPEG-2 audio was a contender for the ATSC standard during the DTV " Grand Alliance " shootout, but lost out to Dolby AC-3 . Technical features of MPEG-2 in ATSC are also valid for ISDB-T , except that in

8320-500: The main TS has aggregated a second program for mobile devices compressed in MPEG-4 H.264 AVC for video and AAC -LC for audio, mainly known as 1seg . MPEG-2 is one of the three supported video coding formats supported by Blu-ray Disc. Early Blu-ray releases typically used MPEG-2 video, but recent releases are almost always in H.264 or occasionally VC-1 . Only MPEG-2 video (MPEG-2 part 2)

8424-439: The method of transmission. The proposals for modulation schemes for digital television were developed when cable operators carried standard-resolution video as uncompressed analog signals. In recent years, cable operators have become accustomed to compressing standard-resolution video for digital cable systems, making it harder to find duplicate 6 MHz channels for local broadcasters on uncompressed "basic" cable. Currently,

8528-488: The most significant being that digital channels take up less bandwidth and the bandwidth allocations are flexible depending on the level of compression and resolution of the transmitted image. This means that digital broadcasters can provide more digital channels in the same space, provide high-definition television service, or provide other non-television services such as multimedia or interactivity. DTV also permits special services such as multiplexing (more than one program on

8632-418: 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 as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of

8736-408: The new ATV standard must be capable of being simulcast on different channels. The new ATV standard also allowed the new DTV signal to be based on entirely new design principles. Although incompatible with the existing NTSC standard, the new DTV standard would be able to incorporate many improvements. A universal standard for scanning formats, aspect ratios, or lines of resolution was not produced by

8840-633: The offer. The ATSC system supports a number of different display resolutions, aspect ratios , and frame rates . The formats are listed here by resolution, form of scanning ( progressive or interlaced ), and number of frames (or fields) per second (see also the TV resolution overview at the end of this article). For transport, ATSC uses the MPEG systems specification, known as an MPEG transport stream , to encapsulate data, subject to certain constraints. ATSC uses 188-byte MPEG transport stream packets to carry data. Before decoding of audio and video takes place,

8944-418: The problem of large numbers of analog receivers being discarded. One superintendent of public works was quoted in 2009 saying; "some of the studies I’ve read in the trade magazines say up to a quarter of American households could be throwing a TV out in the next two years following the regulation change." In Michigan in 2009, one recycler estimated that as many as one household in four would dispose of or recycle

9048-403: The proposed ATSC mobile standards are backward-compatible with existing tuners, despite being added to the standard well after the original standard was in wide use. Mobile reception of some stations will still be more difficult, because 18 UHF channels in the U.S. have been removed from TV service, forcing some broadcasters to stay on VHF. This band requires larger antennas for reception, and

9152-544: The receiver must demodulate and apply error correction to the signal. Then, the transport stream may be demultiplexed into its constituent streams. There are four basic display sizes for ATSC, generally known by referring to the number of lines of the picture height. NTSC and PAL image sizes are smallest, with a width of 720 (or 704) and a height of 480 or 576 lines. The third size is HDTV images that have 720 scan lines in height and are 1280 pixels wide. The largest size has 1080 lines high and 1920 pixels wide. 1080-line video

9256-422: The receiving antenna to the transmitter is not available, because usually higher frequency signals can't pass through obstacles as easily. Television sets with only analog tuners cannot decode digital transmissions. When analog broadcasting over the air ceases, users of sets with analog-only tuners may use other sources of programming (e.g., cable, recorded media) or may purchase set-top converter boxes to tune in

9360-445: The receiving equipment starts picking up interference that overpowers the desired signal or if the signal is too weak to decode. Some equipment will show a garbled picture with significant damage, while other devices may go directly from perfectly decodable video to no video at all or lock up. This phenomenon is known as the digital cliff effect. Block errors may occur when transmission is done with compressed images. A block error in

9464-423: The registration authority for MPEG-2 format identifiers. The registration descriptor of MPEG-2 transport is provided by ISO/IEC 13818-1 in order to enable users of the standard to unambiguously carry data when its format is not necessarily a recognized international standard. This provision will permit the MPEG-2 transport standard to carry all types of data while providing for a method of unambiguous identification of

9568-444: The related NTSC channel numbers, or all stations on a network can use the same number. There is also a standard for distributed transmission systems (DTx), a form of single-frequency network which allows for the synchronised operation of multiple on-channel booster stations . Dolby Digital AC-3 is used as the audio codec , though it was standardized as A/52 by the ATSC. It allows the transport of up to five channels of sound with

9672-403: The same channel), electronic program guides and additional languages (spoken or subtitled). The sale of non-television services may provide an additional revenue source to broadcasters. Digital and analog signals react to interference differently. For example, common problems with analog television include ghosting of images, noise from weak signals and other problems that degrade the quality of

9776-512: The same number of samples per second for both the 1080-line interlaced format and the 720-line format, as 1920*1080*30 is roughly equal to 1280*720*60. A similar equality relationship applies for 576 lines at 25 frame per second versus 480 lines at 30 frames per second. A terrestrial (over-the-air) transmission carries 19.39 megabits of data per second (a fluctuating bandwidth of about 18.3  Mbit/s left after overhead such as error correction, program guide, closed captioning, etc.), compared to

9880-456: The sampling rates defined in MPEG-1 (32, 44.1 and 48 kHz). MPEG-2 Part 7 (ISO/IEC 13818-7), titled Advanced Audio Coding (AAC) specifies a rather different, non-backwards-compatible audio format. This format is most commonly called Advanced Audio Coding (AAC), but was originally called MPEG-2 NBC (non-backwards-compatible). AAC is more efficient than the previous MPEG audio standards, and

9984-463: The shortcomings of MPEG-1. MPEG-1's known weaknesses: Sakae Okubo of NTT was the ITU-T coordinator for developing the H.262/MPEG-2 Part 2 video coding standard and the requirements chairman in MPEG for the MPEG-2 set of standards. The majority of patents underlying MPEG-2 technology are owned by three companies: Sony (311 patents), Thomson (198 patents) and Mitsubishi Electric (119 patents). Hyundai Electronics (now SK Hynix ) developed

10088-399: The standard. See Video profiles and levels . MPEG-2 Part 1 (ISO/IEC 13818-1 and ITU-T Rec. H.222.0), titled Systems , defines two distinct, but related, container formats . One is the transport stream , a data packet format designed to transmit one data packet in four ATM data packets for streaming digital video and audio over fixed or mobile transmission mediums, where the beginning and

10192-542: The time. A digital TV broadcast service was proposed in 1986 by Nippon Telegraph and Telephone (NTT) and the Ministry of Posts and Telecommunication (MPT) in Japan, where there were plans to develop an "Integrated Network System" service. However, it was not possible to practically implement such a digital TV service until the adoption of motion-compensated DCT video compression formats such as MPEG made it possible in

10296-435: The transmission bit rate and make reception easier for more distant or mobile viewers. There are several different ways to receive digital television. One of the oldest means of receiving DTV (and TV in general) is from terrestrial transmitters using an antenna (known as an aerial in some countries). This delivery method is known as digital terrestrial television (DTT). With DTT, viewers are limited to channels that have

10400-421: The use of progressive frames coded within an interlaced video sequence. For example, NBC stations transmit a 1080i60 video sequence, meaning the formal output of the MPEG-2 decoding process is sixty 540-line fields per second. However, for prime-time television shows, those 60 fields can be coded using 24 progressive frames as a base – actually, an 1080p24 video stream (a sequence of 24 progressive frames per second)

10504-451: The video signal. This FM audio signal could be heard using standard radios equipped with the appropriate tuning circuits. However, after the digital television transition , no portable radio manufacturer has yet developed an alternative method for portable radios to play just the audio signal of digital TV channels; DTV radio is not the same thing. The adoption of a broadcast standard incompatible with existing analog receivers has created

10608-409: The world; below are the more widely used standards: Digital television's roots are tied to the availability of inexpensive, high-performance computers . It was not until the 1990s that digital TV became a real possibility. Digital television was previously not practically feasible due to the impractically high bandwidth requirements of uncompressed video , requiring around 200  Mbit/s for

10712-619: Was approved in 2008 and introduces H.264 /AVC video coding to the ATSC system. ATSC supports 5.1-channel surround sound using Dolby Digital 's AC-3 format. Numerous auxiliary datacasting services can also be provided. Many aspects of ATSC were patented , including elements of the MPEG video coding, the AC-3 audio coding, and the 8VSB modulation. The cost of patent licensing, estimated at up to $ 50 per digital TV receiver, had prompted complaints by manufacturers. As with other systems, ATSC depends on numerous interwoven standards, e.g.,

10816-404: Was primarily developed with patent contributions from LG Electronics , which held most of the patents for the ATSC standard. ATSC includes two primary high definition video formats, 1080i and 720p . It also includes standard-definition formats, although initially only HDTV services were launched in the digital format. ATSC can carry multiple channels of information on a single stream, and it

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