Audio and video interfaces and connectors: Difference between revisions

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{{short description|Wikimedia list article}}

{{Refimprove|date=February 2009}}

'''Audio connectors''' and '''video connectors''' are [[electrical connector|electrical]] or [[optical fiber connector|optical connectors]] for carrying [[audio signal|audio]] and [[video signalssignal]]s. '''Audio interfaces''' and '''video interfaces''' define physical parameters and interpretation of signals. For [[digital audio]] and [[digital video]], this can be thought of as defining the [[physical layer]], [[data link layer]], and most or all of the [[application layer]]. For [[analog audio]] and [[analog video]] these functions are all represented in a single signal specification like [[NTSC]] or the direct [[Loudspeaker|speaker]]-driving signal of analog audio. Physical characteristics of the electrical or optical equipment includes the types and numbers of wires required, voltages, frequencies, optical intensity, and the physical design of the connectors. Any data link layer details define how application data is encapsulated (for example for synchronization or error-correction). Application layer details define the actual audio or video format being transmitted, often incorporating a codecs[[codec]]s not specific to the interface, such as [[PCM]], [[MPEG-2]], or the [[DTS Coherent Acoustics codec]]. In some cases, the application layer is left open; for example, [[HDMI]] contains an [[Ethernet]] channel for general data transmission.

Some types of connectors are used by multiple hardware interfaces; for example, [[RCA connectorsconnector]]s are defined both by the [[composite video]] and [[component video]] interfaces, but [[Digital Visual Interface|DVI]] is the only interface that uses the DVI connector. This means that in some cases not all components with physically compatible connectors will actually work together.

In some cases, the application layer is left open; for example, HDMI contains an Ethernet channel for general data transmission.

Some of these connectors, and other types of connectors, are also used at [[radio frequency]] (RF) to connect a radio or television receiver to an antenna or to a cable system; RF connector applications are not further described here. Analog A/V connectors often use [[shielded cablescable]]s to inhibit [[RF interference|radio frequency interference]] (RFI) and [[noise]].

Some types of connectors are used by multiple hardware interfaces; for example, RCA connectors are defined both by the composite video and component video interfaces, but DVI is the only interface that uses the DVI connector. This means that in some cases not all components with physically compatible connectors will actually work together.

For efficiency and simplicity, the same codec or signal convention is used by the storage medium. For example, [[VHS]] tapes can store a magnetic representation of an NTSC signal, and the specification for [[Blu-ray DiscsDisc]]s incorporates PCM, MPEG-2, and DTS. Some playback devices can re-encode audio or video so that the format used for storage does not have to be the same as the format transmitted over the A/V interface (which is helpful if a projector or monitor cannot handle a newer codec).

Some of these connectors, and other types of connectors, are also used at radio frequency (RF) to connect a radio or television receiver to an antenna or to a cable system; RF connector applications are not further described here. Analog A/V connectors often use shielded cables to inhibit radio frequency interference (RFI) and noise.

For efficiency and simplicity, the same codec or signal convention is used by the storage medium. For example, VHS tapes can store a magnetic representation of an NTSC signal, and the specification for Blu-ray Discs incorporates PCM, MPEG-2, and DTS. Some playback devices can re-encode audio or video so that the format used for storage does not have to be the same as the format transmitted over the A/V interface (which is helpful if a projector or monitor cannot handle a newer codec).

== Interfaces and their connectors ==

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| rowspan=5| '''Audio only'''

| rowspan=2 |'''Analog'''

| Often unmarked on consumer audio equipment since it is so common, or labelled with [[headphones]] symbol or as "line out". Computers and other equipment sometimes use [[PC_System_Design_Guide#Color-coding_scheme_for_connectors_and_ports|Microsoft-Intel color coding scheme]], especially when there are multiple input/output plugs.

| [[Phone connector (audio)|3.5 mm TRS minijack]]

|

|-

| [[Balanced audio]]

| 6.35&nbsp;mm [[Phone connector (audio)|TRS audio jack]] (shielded twisted pair),<br>[[XLR connector|XLR]] (shielded twisted pair)

|-

| rowspan=3 |'''Digital'''

| [[S/PDIF]] (Sony/Philips Digital Interconnect Format). Via coaxial or optical cables.

| [[RCA Jack]] (coaxial),<br>[[TOSLINK]] (optical),<br>[[BNC connector|BNC]] (rare)

|-

| [[AES3]] (also known as AES/EBU)

| [[RCA Jack]] (coaxial),<br>[[XLR connector|XLR]] (shielded twisted pair),<br>[[TOSLINK]] (optical),<br>[[BNC connector|BNC]]

|-

| [[MADI]]

| [[BNC connector|BNC]] (coaxial),<br/>[[ST connector|ST]] (optical)

|-

| rowspan=6 |'''Video only'''

| rowspan=5 |'''Analog'''

| [[Video Graphics Array]] (VGA)

| [[D-subminiature]] 15-pin

|-

| [[Composite Video|Composite]]. Often designated by the CVBS acronym, meaning "Color, Video, Blank and Sync".

| [[RCA jack]], normally yellow (often accompanied with red and white for right and left audio channels respectively)

|-

| [[S-Video]] (Separate Video). Carries standard definition video and does not carry audio on the same cable.

| [[Mini-DIN connector|Mini-DIN]] 4-pin

|-

| [[Component Video|Component]]. In popular use, it refers to a type of analog video information that is transmitted or stored as three separate signals. Either [[Component video#RGB analog component video|RGB interfaces]] or [[YPbPr]]

| 3 [[RCA JacksJack]]s

|-

| [[Composite Video|Composite]], [[S-Video]], and [[Component Video|Component]]

| [[Video In Video Out|VIVO]] = [[Mini-DIN connector|Mini-DIN]] 9-pin with breakout cable.

|-

| '''Digital and analog'''

| [[Digital Visual Interface]] (DVI)

| DVI connector

|-

| rowspan=5 |'''Video and audio'''

| rowspan=1 |'''Analog'''

| [[SCART]] (Peritel)

| SCART

|-

| rowspan=4 |'''Digital'''

| [[High-Definition Multimedia Interface]] (HDMI),BNC

| HDMI connector

|-

| [[DisplayPort]]

| DisplayPort connector

|-

| [[HDBaseT]]

| [[8P8C]] connector

|-

| [[IEEE 1394 interface|IEEE 1394 "FireWire"]]

| FireWire or i.LINK connectors

|}

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== Multiple signals ==

Several generic digital data connection standards are designed to carry audio/video data along with other data and power:

* [[USB]] was designed as a single connector to support all needs, including any generic data, audio/video, power, and more; [[DisplayLink]] is its most successful Audio+Video protocol. Until the 3.0 revision, very low data rates meant most A/V needed alternative connectors.

* [[USB-C]] can directly transport USB 3.1, DisplayPort, Thunderbolt, HDMI, and [[Mobile High-Definition Link|MHL]] protocols, with power, and audio and many other protocols are possible.

* [[Thunderbolt (interface)|Thunderbolt]] is the successor to FireWire, a generic high-speed data link with well-defined audio/video uses. The latest Thunderbolt 3 uses USB-C as its connector, though not all USB-C is Thunderbolt-compatible.

* [[FireWire]] is a generic data link with audio/video standards used on Camcorders (particularly [[MiniDV]]), and high-end studio audio and video equipment.

* [[DisplayPort]] carries digital audio and video, as well as auxiliary information, along with its [[Mini DisplayPort]] cousin.

* [[IPod dock connector|Apple 30-pin dock connector]], a docking cradle for Apple iPod, iPhone and iPad, and its [[Lightning (connector)|Lightning]] successor.

* [[Apple Display Connector|ADC]], now-defunct Apple Display Connector

Some digital connection standards were designed from the beginning to primarily carry audio and video signals simultaneously:

* [[HDMI]] combines DVI-compliant uncompressed video data with compressed or uncompressed audio, and supports other protocols.

* [[Mobile High-Definition Link]] (MHL)

Many analog connectors carry both:

* [[F connectorsconnector]]s, also known as RF connectors, were the standard analog connector of the analog era in the Americas, used primarily with [[coaxial cable]] ([[RG-59]] and [[RG-6]]), and have been repurposed for generic digital data connections.

* [[SCART]] was the standard connector of the analog era in [[Europe]].

* [[S-Video]] was an improvement over the F connector.

* [[Phone connector (audio)|Tip-ring connector]] with 4 conductors.

=== S/PDIF ===

The electrical coaxial cable (with [[RCA Jack|RCA jacks]]) or optical fibre ([[TOSLINK]]).

Note that there are no differences in the signals transmitted over optical or coaxial [[S/PDIF]] connectors—both carry exactly the same information. Selection of one over the other rests mainly on the availability of appropriate connectors on the chosen equipment and the preference and convenience of the user. Connections longer than 6 meters or so, or those requiring tight bends, should use coaxial cable, since the high light signal attenuation of [[TOSLINK]] cables limits its effective range.

=== HDMI ===

[[File:HDMI.socket.png|thumb|left|HDMI Type A socket]]

High-Definition Multimedia Interface (HDMI) is a compact audio/video standard for transmitting uncompressed digital data.

[[High-Definition Multimedia Interface]] (HDMI) is a compact audio/video standard for transmitting uncompressed digital data.

There are three HDMI connector types. Type A and Type B were defined by the HDMI 1.0 specification. Type C was defined by the HDMI 1.3 specification.

Type A is electrically compatible with single link DVI-D. Type B is electrically compatible with [[Digital Visual Interface#Connector|dual link DVI-D]] but has not yet been used in any products.

{{clear left}}

===IEEE 1394 "FireWire"===

[[File:FireWire-46 Diagram.svg|left|thumb|The 6-circuit and 4-circuit alpha FireWire 400 connectors]]

IEEE 1394 (branded "FireWire") is a digital data transfer protocol commonly used for digital cameras (common on MiniDV tape camcorders), but also used for computer data and audio data transfers.

[[IEEE 1394]] (branded "FireWire") is a digital data transfer protocol commonly used for [[FireWire camera|digital cameras]] (common on MiniDV tape camcorders), but also used for computer data and audio data transfers.

Unlike Point-to-Point connections listed above, IEEE 1394 is able to host several signals on the same wire, with the data delivered and shown on the destination set. It is also fully bi-directional, with its full bandwidth used in one direction or the other, or split directions up to its maximum.<ref>{{cite web|url=http://www.1394ta.org/about/HANA/HANA_Presentation_041808.pdf |title=Archived copy |accessdate=2010-06-04 |url-status=dead |archiveurl=https://web.archive.org/web/20110606225931/http://www.1394ta.org/about/HANA/HANA_Presentation_041808.pdf |archivedate=2011-06-06 }} Demonstrating the multi-device capabilities of IEEE A/V network.</ref>

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=== DisplayPort ===

[[File:DisplayPort Connector.svg|left|200px|pinout_caption=External connector (source-side) on PCB]]

DisplayPort is a digital display interface standard (approved May 2006, current version 1.4 published on March 1 2016). It defines a new license-free, royalty-free, digital audio/video interconnect, intended to be used primarily between a computer and its display monitor, or a computer and a home-theater system.

[[DisplayPort]] is a digital display interface standard (approved May 2006, current version 1.4 published on March 1 2016). It defines a new license-free, royalty-free, digital audio/video interconnect, intended to be used primarily between a computer and its display monitor, or a computer and a home-theater system.

The video signal is not compatible with [[Digital Visual Interface|DVI]] or [[High-Definition Multimedia Interface|HDMI]], but a DisplayPort connector can pass these signals through. DisplayPort is a competitor to the HDMI connector, the [[de facto]] digital connection for high-definition consumer electronics devices.

== Audio connectors ==