以下是英文解释，希望帮到您：
HDMI (High-Definition Multimedia Interface) 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.[4] HDMI is a digital replacement for analog video standards.
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.[5][6](p. III) 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.[6](§C) 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.[6](§6.3)
Several versions of HDMI have been developed and deployed since 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.[7] 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.[8][9] As of January 6, 2015 (twelve years after the release of the first HDMI specification), over 4 billion HDMI devices have been sold.[10]
HDMI不仅可以满足目前最高画质1080P的分辨率，还能支持DVD Audio等最先进的数字音频格式，支持八声道96kHz或立体声192kHz数码音频传送，而且只用一条HDMI线连接，免除数字音频接线。同时HDMI标准所具备的额外空间可以应用在日后升级的音视频格式中。足以应付一个1080p的视频和一个8声道的音频信号。而因为一个1080p的视频和一个8声道的音频信号需求少于4GB/s，因此HDMI还有很大余量。这允许它可以用一个电缆分别连接DVD播放器，接收器和PRR。此外HDMI支持EDID、DDC2B，因此具有HDMI的设备具有“即插即用”的特点，信号源和显示设备之间会自动进行“协商”，自动选择最合适的视频/音频格式。
与DVI相比HDMI接口的体积更小，而且可同时传输音频及视频信号。DVI的线缆长度不能超过8米，否则将影响画面质量，而HDMI最远可传输15米。只要一条HDMI缆线，就可以取代最多13条模拟传输线，能有效解决家庭娱乐系统背后连线杂乱纠结的问题。
What is HDMI?
Digital interface defined around DVI 1.0 that transmits video and audio on the same physical channel.
Interface defined for use in the consumer market space.
Requires separate licensing from that of DDWG’s DVI.
Allows DVI/HDMI products to be sold in consumer products
Supports the use of HDCP copy protection.
Utilizes VESA’s Display Data Channel to read E-EDID from a display.
Defines a different connector from that used on DVI.
Supports optional CEC (Consumer Electronics Control), which allows high level control of all A/V products in a user environment.
DVI 1.0: The Physical Interface
Digital Visual Interface (DVI) was developed by a group called the Digital Display Working Group or DDWG for the PC market.
The interface is a high speed digital serial interface based on Transition Minimized Differential Signaling or TMDS.
Source synchronous architecture. Uses a separate channel to transmit the clock.
Used to provide variable data rates to handle the various VESA supported display resolutions.
A complete connection from the source to the sink devices uses three data channels (RGB/YCbCr) and a clock.
HDMI = DVI + Audio
Using the DVI physical link to transmit video/graphics
Audio is added as a logical layer to the DVI phy.
Digital audio processed into packets of data
These packets are scheduled for transmission during existing horizontal and vertical blanking times within a frame.
In addition, HDMI implements a packet called an infoFrame.
InfoFramesare structures defined in the EIA-861B specification
EIA-861B is spec for DTV and uncompressed high speed digital interfaces.
What is HDMI Data?
There are three categories of data that is transmitted via an HDMI link.
Video Data –Video pixel data (8b data encoded to 10b), and Guard Bands (fixed 10b pattern)
Data Island –Packet data, which can be either audio samples or Infoframes(TERC4 encoded, 4b encoded to 10b) as well as its own Guard Band (fixed 10b pattern).
Control –Control period coding, in which we find HSYNC, VSYNC (2b to 10b encoding) and a Preamble (used to determine whether subsequent data is video or data island)
Transmission of Video/Graphics
HDMI transmits 24bit pixel data via three separate channels.
Pixel rates supported are 25MHz to 165MHz.
This is exactly the same as single link DVI 1.0
Also supports video rates below 25MHz e.g. 13.5MHz for 480i NTSC signals.
Achieves this through a “pixel-repetition”scheme.
Can handle pixel data in RGB, YCbCr(4-4-4), YCbCr(4-2-2) formats.
In all cases 24 bits of data per pixel clock are transmitted.
Transmission of Audio
Basic Audio is provided via an IEC60958 audio stream at 33kHz, 44.1kHz, or 48kHz.
Accommodates any normal stereo audio stream.
Optionally this stream can be sent as a single channel at 192kHz.
Can support IEC61937 compressed formats as found in surround-sound, Dolby Digital, etc. at rates up to 192kHz.
Infoframes and HDMI
EIA/CEA-861B specifies a special packet called an infoframe
HDMI sources and sinks are expected to use two basic infoframes.
AVI (Auxiliary Video Information) Infoframe
Communicates Colorimetry, Picture aspect ratio, Pixel-Repetition factor, RGB or YCbCrindicator, and others specified within 861B standard.
Audio Infoframe
Communicates, Channel count, Coding Type, Sample size, Sample frequency, Channel allocation and other audio specific information.
There are other types of infoframes that are supported by the 861B standard, but are optional with respect to HDMI specification.
HDMI系统，参考这个网站：
http://baike.baidu.com/pic/6/11792145016751160.jpg
参考资料： 百度百科
