Scope
Every industry has its acronyms, abbreviations, and technical terms. This collection of current and often-used TV terminology is intended to assist anyone who converses with TV management and engineers about their technical needs. This is particularly aimed anyone involved in the sale, configuration and use of Linear Acoustic and Junger TV audio processors.
Glossary
1770 also ITU 1770, .BS. 1770 TV audio loudness measurement standard. See ITU
2.0 a 2-ch audio signal. Usually stereo but may be the same mono program on both channels
2.1 2.0 with an LFE channel
3.0. Left, Right and Center audio channels
3.1: Left, Right and Center audio channels with an LFE channel.
3G-SDI 3Gbs bit rate of HD digital video up to 1080p 60 fps
5.1 Front Left, Front Right, Center, LFE, Left Surround, Right Surround audio channels. May also be written: Lf, Rf, C, LFE, Ls, Rs
5.1.2 as above plus two front height channels, Left Front Height (LFH) and Right Front Height (LFH)
5.1.4. Lf, Rf, C, LFE, Ls, Rs, Lfh, Rfh Lrh, Rrh audio channels.
6G-SDI 6Gbs bit rate. 1080p 120 fps and 2160p 30 fps. UHD aka 4K: 3840 x 2160 (always progressive scan)
7.1 Lf, Rf, C, LFE, Ls, Rs, Lss, Rss, Lrs, Rrs (ss = side surround, rs = rear surround)
7.1.4 Lf, Rf, C, LFE, Ls, Rs, Lss, Rss, Lrs, Rrs, Lfh, Rfh Lrh, Rrh
NOTE: the “h” in the above formats means height channels.
8K 7680 x 4320 (always progressive scan)
The i, as in 1080i, refers to interlaced frames of video
The p, as in 1080p, refers to progressive frames of video
12G-SDI 2Gbs bitrate up to 2160p 60fps. UHD aka 4K: 3840 x 2160 (always progressive scan)
24G-SDI 24Gbs bitratre up to 2160p 120 fps, 4320p 30 fps
UHD aka 4K: 3840 x 2160 (always progressive scan)
A/85 TV audio loudness standard for ATSC based broadcasts. The standard was developed in response to the CALM Act
AAF Advanced Authoring Format (AAF). This is a multimedia file format designed for exchanging digital video, audio, and metadata.
AC-3 Technical name for Dolby Digital audio encoding. It is the Dolby terminology used in standards documents, such as ATSC, ITU, EBU. See Dolby Digital.
ADM An ITU standard meaning "Audio Definition Model"
AES Audio Engineering Society. An international audio standards and education industry group
AES3 An AES standard describing a 2-channel digital audio stream using balanced or unbalanced lines.
AES50. AES50 is anAudio Engineering Society (AES) open standard for the bi-directional transmission of multi-channel digital audio. Features/limits AES50 include:
fixed latency of 0.625milliseconds
supports up to 48 bi-directional audio channels @48 kHz sampling or maximum of 24 bi-directional channels at 96 kHz
100m cable runs
point-to-point connections only. AES50 is NOT standard Ethernet
AES10 An AES standard that defines MADI (Multichannel Audio Digital Interface).
can carry up to 56 or 64 channels of audio in a single connection.
MADI can be carried on a coaxial (copper) cable or on fibre optic cable.
AES67 An AES standard that defines an audio over IP protocol.
A/85 also ATSC A/85. This is a standard of the ATSC. These rules, which required commercials to match the average volume of surrounding programming, officially went into effect on December 13, 2011. ATSC 1 TV stations were required to comply the A/85 technical regulations one year later, on December 13, 2012.
AMWA Advance Media Workflow Association. An industry association behind NMOS and AAF specifications. See NMOS
aspect ratio The ratio of screen width to screen height.
ATMOS Dolby’s brand name for an immersive audio experience using Dolby technologies. This is Dolby’s brand name to describe the immersive experience, not a specific technology.
ATSC Advanced Television Systems Committee . An international industry group responsible for the terrestrial DTV standard in the North America and some other countries
ATSC 1.0 The first generation of an international DTV standard for terrestial broadcasting. It is used in North America and several other locations around the world
ATSC 3.0 The latest generation of the ATSC standard. Not yet mandatory anywhere in the world ,but in use in several countries.
BS.1770 A perceptual audio loudness standard; see ITU BS.1770
CALM Act Described briefly, the CALM Act required the Federal Communications Commission (FCC) to enact rules that require commercials to have the same average volume as the programs they accompany. Enacted by U.S. Congress in 2010. The ATSC A/85 standard was the result of the CALM Act.
Cinema 4K 4096 x 2160 (always progressive scan)
Dante A proprietary AoIP format offered by Audinate. Dante is the defacto standard AoIP format used in the Live Sound and Installed Sound system markets. It is often found in TV since there is a lot of crossover between Live Sound and TV audio products. In particular audio consoles, stage boxes, audio processors, intercom systems, audio routers and format convertors.
Dolby Digital. Also DD. The brand name for audio encoding and decoding products that use audio bit rate reduction to reduce the needed bandwidth and data-rate for last-mile delivery. That is, delivery to the end user. It can encode up to 8 channels of audio. It does not have the audio quality needed to be decoded, edited, and re-encoded without artifacts. Dolby Digital uses an encoding scheme Dolby calls AC-3. Broadcasters will often refer to Dolby, Dolby Digital and AC-3 to mean the same thing. Dolby Digital is used in ATSC 1.0, DVB, DVD, cable, and satellite distribution
Dolby Digital Plus. Also DD+. The brand name for an improved (better than AC-3) audio encoder intended for last mile delivery. Dolby Digital Plus is also called E-AC-3. It can encode up to 8 channels of audio.
Dolby Digital Plus JOC, Also DD+JOC (se JOC) The brand name for an improved DD+ audio encoder. It can encode up to 16 channels of audio. It id also intended for last-mile delivery
Dolby E The brand name of an audio codec that encodes up to 8 channels of audio at higher bitrate (better audio quality) than Dolby Digital or Dolby Digital Plus. It is used to deliver audio from a remote location back to a studio where the audio can be decoded, edited, and re-encoded for delivery to the end user or for delivery for additional editing.
Downmix Downmixing takes an audio signal with a larger input channel count than desired, and mixes it down to the desired output format. An example is a 5.1 channel to stereo downmix.
DRC Dynamic Range Control
E-AC-3 “Enhanced AC-3” is the technical name for Dolby Digital Plus
fps frames per second
Gbs or Gbps or G. gigabits per second
H.264 AVC video codec
H.265 HEVC video codec
HD High Definition. Usually referring to video, but is also used in an audio context with varying meanings. For TV, HD may be 720p, 1080i or 1080p aspect ratio and interlace values.
HDR High Dynamic Range video. Dolby Vision, HDR10, HDR10+ are some of the HDR technologies in use
HD-SDI also HD. 1.5Gbs bit rate of uncompressed standard definition video up to 1080i
1280 x 720 is called 720i or 720p depending on how the pixels are scanned, interlaced or progressive.
HEVC High Efficiency Video Codec. Also known as H.265
ITU BS.1770 An ITU standard for making perceptual audio loudness measurements. This standard is referred to by loudness standards except North America and US possessions.
JOC Dolby proprietary Joint Object Coding. JOC enables Atmos in Dolby Digital Plus. Commonly called DD+ w ATMOS (to consumers), or DD+ JOC (internal usage only)
LFE Low Frequency Effects channel. This is a dedicated channel in a soundtrack for low frequency effects. For example, thunder, explosions, rumbles from earthquakes, etc. These sounds will be played out of a subwoofer and/or other speakers in a consumer’s audio system according to how the user configures their home audio receiver. The LFE channel is NOT a subwoofer channel per se. It is a channel in the soundtrack itself, not the output of the AV receiver.
In audio sources any .n channels are transmitted with less than full audio bandwidth and less than the number of bits used for the primary channels. This saves encoding bits at little or no fidelity loss due to the channel only carrying very low audio frequencies (which require fewer bits for accurate reproduction).
LKFS Loudness "K-weighted" Full Scale. This is a defined measurement that represents the perceptual loudness of an audio signal. It uses the same measurement definition as an LUFS measurement. LKFS and LUFS measurements are identical. U.S. loudness regulation A/85 uses LKFS.
LUFS Loudness Units Full Scale. LUFS is used by EBU. See LKFS.
MADI See AES10.
Mezzanine A bit rate reduced video transmission and storage format, with little or no degradation from repeated encode/decode cycles.
MPEG Motion Pictures Experts Group. A source of audio and video reduced bit rate codecs and other standards for audio and video.
NGA Next Generation Audio. Capability to have more than 5.1 audio channels. Immersive audio is part of NGA but NGA is much more than immersive.
NMOS Networked Media Open Specification. AMWA, Advanced Media Workflow Association is a group that creates specifications for media professionals using networked media. These are not standards. Specifications like this may or may not be used as the basis of standards written by SMPTE, EBU, AES, or other standards bodies. Even though NMOS is not a national or international Standard, the NMOS standards IS-04 and IS-05 are being implemented by several manufacturers in the media space because of the utility of the specifications.
IS-04 NMOS Discovery and Registration Specification
IS-05 NMOS Device Connection Management
IS-07 NMOS Event & Tally Specification
IS-08 NMOS Audio Channel Mapping
IS-09 NMOS System Parameters
IS-10 NMOS Authorization
IS-11 NMOS Stream Compatibility Management
IS-12 NMOS Control Protocol
IS-13 NMOS Annotation
IS-14 NMOS Device Configuration
NTSC National Television Systems Committee. An analog television (monochrome and color) standard used in North America, American protectorates, Japan and some Latin American countries. Also referred to as Never The Same Color by many TV engineers.
Object Based Audio
This technique takes audio elements, called objects, and assigns them a coordinate in space. Imagine an aircraft flying above characters in a scene. The airplane sound (object) is then assigned to some of the speakers, at specified levels. The speakers used and the levels place the element in the audio space created by the speakers. The object can move through the audio space using metadata. The object moves by its changing levels and the speakers used, in real time.
Typically, the 5.1 surround sound mix is considered the base mix. These 6 channels have continuous (or nearly continuous) audio and comprise all of the audio needed to create a good soundtrack. The additional channels in a 5.1.4, 7.1 or 7.1.4 mix can then use objects that create an immersive experience. Home theater might use 5.1.4, 7.1 or 7.1.4 channels to create an immersive experience. Dolby Cinema sound can use 64 simultaneous audio tracks and 128 discrete audio channels. The Sphere, in Las Vegas, has 256 discrete audio channels driving 167,000 speakers.
OTT "Over The Top" television. This is the delivery of TV content "on top of" Internet service. A generic way to describe streaming services like Netflix, Hulu, etc.
PAL An analog color TV encoding standard used around the world (but not in North America)
Pixel ratio The ratio of horizontal vs vertical pixels in a digital display.
SD = 640 x 480 and is called a 480i, or 480i30 picture.
The i stands for interlaced. All of the odd rows of pixels are scanned (filled with color), and then all of the even rows are scanned. The slow fade of the pixel’s color, along with human persistence of vision, means the brain “sees” a full frame of video. This is repeated 30 times a second for a frame rate of 30 fps. See commonly used frame rates and pixel ratios under SDI.
Quad-Link 3G-SDI 4x 3G-SDI streams used to carry a 4K (UHD) video program. Each stream carrying 1/4 (or one quadrant) of the total image
RTLL Dolby's Real-Time Loudness Leveler. Dolby’s Loudness control algorithm, that competes against our AEROMAX, APTO, and Junger's Level Magic
SD Standard Definition TV with an aspect ratio of 4:3. This is what NTSC analog video is. 640 x 480 pixel ration and interlaced video is called 480i
SDI Serial Digital Interface. A serial data protocol for delivery of video formats from low res video up to 7680 x 4320 (8K) at 60fps. It can handle bit rates from 143Mbs to 48GB (47.52Gbs). SDI video can carry 16 channels of audio, serial time code, closed captioning, Active Format Description and user data, in addition to video. There have been different versions of SDI over the decades. See below.
Commonly used pixel height-frame order- resolution
SDI video rates frame rate common name
SD-SDI: 270 Mbs 480i SD
HD-SDI: 1.485 Gbs 720p, 1080i HD
Dual Link HD-SDI 1080p60 dual link HD
3G-SDI: 3.97 GBs 1080p60 3G SDI
12G-SDI: 11.88 GBs 2160p60 4K
24G-SDI: 23.67 GBs 2160p60, 4320p30 8K
48G-SDI: 47.52 GBs 4320p60 48G 4K
SDR Standard Dynamic Range video. Used differentiate a video program using HDR from one that is not using HDR.
SMPTE Society of Motion Pictures and Television Engineers. An international, industry standards organization, for film and TV. A very important standard is the latest version for networked video, audio and related signals and data. See ST2110 below.
ST2110: SMPTE standard for media over managed Ethernet networks
ST2110-10: Timing and definitions
ST2110-20: uncompressed video over Ethernet
ST2110-21: control of video traffic and timing in Ethernet networks
ST2110-30: uncompressed AoIP
ST 2110-30 Level A 1 - 8 audio channel streams, in 1ms packets
ST 2110-30 Level B 1 - 8 audio channel streams, in 0.125 ms packets
ST 2110-30 Level C 1 - 64 audio channel streams, in 0.125 ms packets
ST2110-31: compressed AoIP
ST2110-40: Ancillary data over IP
TruePeak. also TP. The measure of the absolute highest amplitude of a digital audio signal. In order to ensure that intersample peaks are detected the measurement sampling rate must be a minimum of 4x the audio sample rate. For 48 kHz sampled audio, the oversampling rate must be at least 192 kHz to find the TP value.
UHD Ultra High Definition video (also called 4K video
Upmix Upmixing is an audio processing technique used to take an input signal and provide more channels at the output. Examples are stereo in and 5.1 out, or 5.1 in and 5.1.4 out.