The High-Definition Multimedia Interface (HDMI) is a compact audio/video connector interface for transmitting uncompressed digital streams. It represents a digital alternative to consumer analog standards such as Radio Frequency (RF) coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, and VGA. HDMI connects digital audio/video sources such as set-top boxes, Blu-ray Disc players, personal computers, video game consoles, and AV receivers to compatible digital audio devices, computer monitors, and digital televisions.

HDMI supports, on a single cable, any TV or PC video format including standard, enhanced, and high-definition video along with up to 8 channels of digital audio. It is independent of the various digital television standards such as ATSC and DVB as these are encapsulations of compressed MPEG video streams (which can be decoded and output as uncompressed video stream on HDMI).

HDMI products started shipping in autumn 2003. Over 800 CE and PC companies have adopted the HDMI specification (HDMI Adopters). HDMI began to appear on consumer HDTV camcorders and digital still cameras in 2006. Shipments of HDMI are expected to exceed that of Digital Visual Interface (DVI) in 2008, driven primarily by the Consumer Electronics (CE) Market.

Overview

HDMI supports, on a single cable, any TV or PC video format including standard, enhanced, and high-definition video along with up to 8 channels of digital audio. HDMI encodes the video data into TMDS for uncompressed digital transmission over HDMI.

HDMI devices are manufactured to adhere to various versions of the specification, where each version is given a number such as 1.0, 1.2, or 1.3a. Each subsequent version of the specification uses the same kind of cable but increases the bandwidth and/or capabilities of what can be transmitted over the cable. For example the previous maximum pixel clock rate of HDMI interface was 165 MHz which was sufficient for supporting 1080p at 60 Hz and WUXGA (1920x1200) at 60 Hz. HDMI 1.3 increased that to 340 MHz which allows for higher resolution, such as WQXGA (2560x1600), across a single digital link.

HDMI supports 8 channel uncompressed digital audio at 192 kHz sample rate with 24 bits/sample as well as compressed audio streams such as Dolby Digital and DTS. HDMI supports up to 8 channels of one-bit DSD audio, which is used on Super Audio CDs, at rates up to 4x that of Super Audio CD. With version 1.3, HDMI also supports lossless compressed audio streams such as Dolby TrueHD and DTS-HD Master Audio.