Term:High-Definition Multimedia Interface [HDMI]

HDMI is a display and audio interface specification. As its name implies it’s designed to support high definition video, as well as high quality audio. Most commonly used as an interface between an entertainment system or video game and a television, HDMI has also gained popularity as an interface between computers and televisions as well.

HDMI (High-Definition Multimedia Interface)
The HDMI logo with the acronym "HDMI" in a large font at the top with the unabbreviated term (High Definition Multimedia Interface) below in a smaller typeface. There is a trademark logo to the right of HDMI.
Type Digital audio/video/data connector
Designer
HDMI Forum (83 companies)
Designed December 2002; 18 years ago (2002-12)
Manufacturer HDMI Adopters (over 1,700 companies)
Superseded DVI, VGA, SCART, RGB Component
Width 13.9 mm (type A), 10.42 mm (type C), 6.4 mm (type D)
Height 4.45 mm (type A), 2.42 mm (type C), 2.8 mm (type D)
Hot pluggable Yes
External Yes
Audio signal LPCM, Dolby Digital, DTS, DVD-Audio, Dolby Digital Plus, Dolby TrueHD, DTS-HD High Resolution Audio, DTS-HD Master Audio, MPCM, DSD, DST, Dolby Atmos, DTS:X
Video signal Maximum resolution limited by available bandwidth
Pins Types A, C, & D (19), Type B (29)
Data signal Yes
Bitrate Up to 48 Gbit/s, as of HDMI 2.1
Protocol TMDS, Fixed Rate Link (FRL)
A diagram of a type A HDMI receptacle, showing 10 pins on the top row and 9 pins on the bottom row (total 19 pins).
HDMI type A receptacle
Pin 1 TMDS Data2+
Pin 2 TMDS Data2 Shield
Pin 3 TMDS Data2−
Pin 4 TMDS Data1+
Pin 5 TMDS Data1 Shield
Pin 6 TMDS Data1−
Pin 7 TMDS Data0+
Pin 8 TMDS Data0 Shield
Pin 9 TMDS Data0−
Pin 10 TMDS Clock+
Pin 11 TMDS Clock Shield
Pin 12 TMDS Clock−
Pin 13 CEC
Pin 14
Pin 15 SCL (I2C serial clock for DDC)
Pin 16 SDA (I2C serial data for DDC)
Pin 17 Ground (for DDC, CEC, ARC, and HEC)
Pin 18 +5 V (min. 0.055 A)
Pin 19
  • Hot Plug Detect (all versions)
  • HEAC− (HDMI 1.4+, optional, HDMI Ethernet Channel and Audio Return Channel)

High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.

An AV receiver for use in home cinema from 2012. The upper row of connectors are HDMI.

HDMI implements the EIA/CEA-861 standards, which define video formats and waveforms, transport of compressed and uncompressed LPCM audio, auxiliary data, and implementations of the VESA EDID. CEA-861 signals carried by HDMI are electrically compatible with the CEA-861 signals used by the Digital Visual Interface (DVI). No signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used. The CEC (Consumer Electronics Control) capability allows HDMI devices to control each other when necessary and allows the user to operate multiple devices with one handheld remote control device.

Several versions of HDMI have been developed and deployed since the initial release of the technology, but all use the same cable and connector. Other than improved audio and video capacity, performance, resolution and color spaces, newer versions have optional advanced features such as 3D, Ethernet data connection, and CEC (Consumer Electronics Control) extensions.

Production of consumer HDMI products started in late 2003. In Europe, either DVI-HDCP or HDMI is included in the HD ready in-store labeling specification for TV sets for HDTV, formulated by EICTA with SES Astra in 2005. HDMI began to appear on consumer HDTVs in 2004 and camcorders and digital still cameras in 2006. As of January 6, 2015 (twelve years after the release of the first HDMI specification), over 4 billion HDMI devices have been sold.

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