Definition: HDMI

(High-Definition Multimedia Interface) A digital interface for audio and video that provides a single-cable solution for home theater and consumer electronics equipment such as TVs, Blu-ray/DVD players and set-top boxes. Introduced in 2002, one HDMI cable took the place of nine different analog audio and video cables.

HDMI supports eight channels of 24-bit uncompressed audio at 192kHz and 4K video resolution up to 4096x2160 (as of HDMI 1.4). It also provides copy protection, A/V equipment control, 5 volts of power and compatibility with DVI and DisplayPort interfaces. For more HDMI details, look up the following:

Version summary, see HDMI versions.
Cable versions, see HDMI cable types.
A/V control, see HDMI CEC.
Compatibility, see HDMI-DVI compatibility and DisplayPort.
Audio return channel, see HDMI ARC.
Copy protection, see HDCP.

Common 19-Pin Connectors

Type A is for TVs and home theater equipment, while camcorders and cellphones use Type C and D. A more secure Type E is used in vehicles, and a 29-pin Type B supports dual-link DVI resolution (see DVI).

HDMI vs. All the Others

This earlier Roku streaming hub was on the market during the transition stage from analog to digital TV. See A/V ports.

An HDMI Switch

HDMI switches let several HDMI sources plug into a TV with only one HDMI input. This Oppo unit switches three inputs. See HDMI switch. (Image courtesy of Oppo Digital, Inc., www.oppodigital.com)