Digital television

digitaldigital TVDTVDTdigital channeldigitallydigital broadcastingdigital signaldigital formatdigital-only
Digital television (DTV) is the transmission of television audiovisual signals using digital encoding, in contrast to the earlier analog television technology which used analog signals.wikipedia
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Analog television

analoganalogueanalogue television
All broadcast television systems used analog signals before the arrival of digital television (DTV).

Color television

colorcolour televisioncolour
Broadcasters began to switch from analog color television technology to digital television around 2006.

Digital television transition

digital switchoveranalog shutdowntransition
However, after the transition of many countries to digital TV, no portable radio manufacturer has yet developed an alternative method for portable radios to play just the audio signal of digital TV channels.
The digital television transition, also called the digital switchover (DSO), the analog switch-off (ASO), the digital migration, or the analog shutdown, is the process in which older analog television broadcasting technology is converted to and replaced by digital television.

Digital Video Broadcasting

DVBDigital Video BroadcastDVB Project
Digital Video Broadcasting (DVB) is a set of international open standards for digital television.

ATSC standards

ATSCdigitalATSC standard
Advanced Television Systems Committee (ATSC) standards are a set of standards for digital television transmission over terrestrial, cable, and satellite networks.

ISDB

ISDB-TIntegrated Services Digital BroadcastingISDB-S
1seg (1-segment) is a special form of ISDB.
The Integrated Services Digital Broadcasting (ISDB; Japanese: 統合デジタル放送サービス, Tōgō dejitaru hōsō sābisu) is a Japanese standard for digital television (DTV) and digital radio used by the country's radio and television networks.

ISDB-T International

SBTVDISDB-TbSBTV
ISDB-T International, or SBTVD, short for Sistema Brasileiro de Televisão Digital (Brazilian Digital Television System), is a technical standard for digital television broadcast used in Brazil, Argentina, Peru, Botswana, Chile, Honduras, Venezuela, Ecuador, Costa Rica, Paraguay, Philippines, Bolivia, Nicaragua, El Salvador and Uruguay, based on the Japanese ISDB-T standard.

Digital Terrestrial Multimedia Broadcast

DTMBDMB-T/HDMB-T
DTMB (Digital Terrestrial Multimedia Broadcast) is the digital TV standard for mobile and fixed terminals used in Cambodia, the Comoros, Mainland China, Cuba, East Timor, Hong Kong, Laos, Macau and Pakistan.

Television

TVtelevisedtelevisions
At the end of the first decade of the 2000s, digital television transmissions greatly increased in popularity.

Orthogonal frequency-division multiplexing

OFDMCOFDMOFDM system comparison table
The question of the relative technical merits of COFDM versus 8VSB for terrestrial digital television has been a subject of some controversy, especially between European and North American technologists and regulators.

Standard-definition television

SDTVstandard definitionSD
Digital television was previously not practically feasible due to the impractically high bandwidth requirements of uncompressed digital video, requiring around 200Mbps bit-rate for a standard-definition television (SDTV) signal, and over 1Gbps for high-definition television (HDTV). 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).
SDTV and high-definition television (HDTV) are the two categories of display formats for digital television (DTV) transmissions.

Radio

radio communicationradio communicationswireless
Digital television (DTV) transmission systems, which replaced older analog television in a transition beginning in 2006, use image compression and high efficiency digital modulation such as OFDM and 8VSB to transmit HDTV video within a smaller bandwidth than the old analog channels, saving scarce radio spectrum space.

Discrete cosine transform

DCTiDCTinverse discrete cosine transform
Digital TV became practically feasible in the early 1990s due to a major technological development, discrete cosine transform (DCT) video compression.
It is used in most digital media, including digital images (such as JPEG and HEIF, where small high-frequency components can be discarded), digital video (such as MPEG, H.26x and Vorbis), digital audio (such as Dolby Digital, MP3 and AAC), digital television (such as SDTV, HDTV and VOD), digital radio (such as AAC+ and DAB+), and speech coding (such as AAC-LD, Siren and Opus).

High-definition television

HDTVhigh definitionHD
Digital television was previously not practically feasible due to the impractically high bandwidth requirements of uncompressed digital video, requiring around 200Mbps bit-rate for a standard-definition television (SDTV) signal, and over 1Gbps for high-definition television (HDTV). 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). A broadcaster may opt to use 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 can be either analog or digital television.

Digital video

videodigitaldigitally
Digital television was previously not practically feasible due to the impractically high bandwidth requirements of uncompressed digital video, requiring around 200Mbps bit-rate for a standard-definition television (SDTV) signal, and over 1Gbps for high-definition television (HDTV).
It was succeeded in 1994 by MPEG-2/H.262, which became the standard video format for DVD and SD digital television.

16:9 aspect ratio

16:91.78:1widescreen
Each of these uses a 16:9 aspect ratio. In terms of rectangular pixels, NTSC countries 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.
Since 2009, it has become the most common aspect ratio for televisions and computer monitors and is also the international standard format of HDTV, Full HD, non-HD digital television and analog widescreen television.

NTSC

analogNTSC-M30p
In terms of rectangular pixels, NTSC countries 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.
Most countries using the NTSC standard, as well as those using other analog television standards, have switched to, or are in process of switching to, newer digital television standards, with there being at least four different standards in use around the world.

Video codec

codecvideo decodingcodecs
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 34Mbps bit-rate and near-studio-quality HDTV at about 70–140 Mbps bit-rate.
MPEG-2 became the standard video format for DVD and SD digital television.

Moving Picture Experts Group

MPEGMotion Picture Experts GroupMPEG encoding
DCT coding is a lossy compression technique that was first proposed for image compression by Nasir Ahmed in 1972, and was later adapted into a motion-compensated DCT video coding algorithm, for video coding standards such as the H.26x formats from 1988 onwards and the MPEG formats from 1991 onwards.

Aspect ratio (image)

4:3aspect ratio16:9
In terms of rectangular pixels, NTSC countries 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. 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).
Two common 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.

Digital terrestrial television

digitalDTTdigital terrestrial
The first digital terrestrial platform was launched in November 1998 as ONdigital in the United Kingdom, using the DVB-T standard. 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).
As of 6 February 2015, Greece has completed its transition to digital TV.

Video coding format

video coding standardsvideo codingvideo coding standard
DCT coding is a lossy compression technique that was first proposed for image compression by Nasir Ahmed in 1972, and was later adapted into a motion-compensated DCT video coding algorithm, for video coding standards such as the H.26x formats from 1988 onwards and the MPEG formats from 1991 onwards.
MPEG-2 became the standard video format for DVD and SD digital television.

High-definition video

HDhigh definitionhigh-definition
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).

HD Radio

HDHD2HD-2
A broadcaster may opt to use 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.
The multiple services are similar to the digital subchannels found in ATSC-compliant digital television using multiplexed broadcasting.

8VSB

8-VSB8-Bit Vestigal SidebandATSC
Early 8VSB DTV (digital television) receivers often had difficulty receiving a signal in urban environments.