2002年4月，日立、松下、飞利浦、索尼、汤姆逊、东芝和Silicon Image七家公司联合组成HDMI组织。在中国，兆龙，秋叶原，绿联科技，北棋科技等是HDMI标准的推崇者和技术的领先者。HDMI能高品质地传输未经压缩的高清视频和多声道音频数据，最高数据传输速度为5Gbps。同时无需在信号传送前进行数/模或者模/数转换，可以保证最高质量的影音信号传送。

　HDMI Type A socket. 　　HDMI的规格书中规定了三种HDMI接头, 分别是: 　　
  HDMI脚位配置

 
HDMI AType

 Pin定义
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 CEC
14 Reserved (N.C. on device)
15 SCL
16 SDA
17 DDC/CEC Ground
18 +5V Power
19 Hot Plug Detect
HDMI B Type

　　总共有29pin, 可传输HDMI A type两倍的TMDS资料量, 相对等于DVI Dual-Link传输, 用于传输高分辨率(WQXGA 2560x1600以上)。 (因为HDMI A type 只有Single-Link的TMDS传输, 如果要传输成HDMI B type的讯号, 则必须要两倍的传输效率, 会造成TMDS的Tx、Rx的工作频率必须提高至270MHz以上。 而在HDMI 1.3 IC出现之前, 市面上大部分的TMDS Tx、Rx只能稳定在165MHz以下工作。) 　　
Pin Pin定义
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 TMDS Data5+
14 TMDS Data5 Shield
15 TMDS Data5-
16 TMDS Data4+
17 TMDS Data4 Shield
18 TMDS Data4-
19 TMDS Data3+
20 TMDS Data3 Shield
21 TMDS Data3-
22 CEC
23 Reserved (N.C. on device)
24 Reserved (N.C. on device)
25 SCL
26 SDA
27 DDC/CEC Ground
28 +5V Power
29 Hot Plug Detect
HDMI C Type

　　总共有19pin, 可以说是缩小版的HDMI A type, 但脚位定义有所改变。 主要是用在便携式装置上, 例如DV、数码相机、便携式多媒体播放机等。 现在已有SONY HDR-DR5E DV利用此规格接头作为影像输出接口。(常常有人称为该规格为mini-HDMI, 这可算是自行胡乱创造的名称, 实际上HDMI官方并没此名称。)
HDMI D Type

HDMI Type D，俗称Micro HDMI 是定义为HDMI 1.4版本的，保持hdmi标准的19pin .但是尺寸与微型USB的接口差不多，尺寸为2.8 mm × 6.4 mm,比mini hdmi (2.42 mm × 10.42 mm)小很多，主要应用在一些小型的移动设备上，如手机，MP4等等。 　　对于手机的厂家来说，不管怎么努力，手机的屏幕还是太小，要想更多人看清，将视频输出到外部显示设备无疑是必须的，在XT800之前，已有数款机型支持AV模拟输出，通过特制3.5mm转接线来实现CVBS复合信号+立体声音频，不过这一接口最大的局限就是清晰度超低，320x240的分辨率使得这种输出仅限于比较简单的应用，况且转接线的体积都不小，使用并不方便。 　　眼看HDMI接口电视、投影机、显示器越来越多，采用HDMi接口已经成为大势所趋，标准HDMI接口分为AB两种类型，不过我们常见的都是A型口，B型口由于是双通道超宽结构基本上见不到厂家使用，标准A型口大约15mm宽，这对于家电产品自然不在话下，但在数码产品上使用显然占地方太大了，于是乎DV和DC产品普遍出现了HDMIC型口，也就是MiniHDMI接口。 　　不过对于手机而言，C型口依然有点大，于是D型口就应运而生，由于发布时间较短，到现在也不过半年时间，接口太小，对于高频率视频信号的传输、防静电要求等都比A型口要困难的多，XT800是我们首先有机会了解到的HDMID型口应用设备，而转接线就比较难找，笔者经多方面寻找，终于在淘宝上找到了一根绿联科技的D型口转A型口线材，有了它，连接电视、显示器、投影机都不再是难事。 　　一端为标准的HDMI插头，一端为Micro HDMI(D type)手机，目前部份手机有此接口。如：Motorola XT800,Nokia N8 and HTC EVO 4G 。 　　
Pin Pin定义
1 TMDS Data2 Shield
2 TMDS Data2+
3 TMDS Data2–
4 TMDS Data1 Shield
5 TMDS Data1+
6 TMDS Data1–
7 TMDS Data0 Shield
8 TMDS Data0+
9 TMDS Data0–
10 TMDS Clock Shield
11 TMDS Clock+
12 TMDS Clock–
13 DDC/CEC Ground
14 CEC
15 SCL
16 SDA
17 Reserved (N.C. on device)
18 +5V Power
19 Hot Plug Detect

　英文定义： 　　 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. 　　zRequires separate licensing from that of DDWG’s DVI. 　　zAllows 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. 　　zSource synchronous architecture. Uses a separate channel to transmit the clock. 　　zUsed 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. 　　zDigital audio processed into packets of data 　　zThese packets are scheduled for transmission during existing horizontal and vertical blanking times within a frame. 　　 In addition, HDMI implements a packet called an infoFrame. 　　zInfoFramesare structures defined in the EIA-861B specification 　　zEIA-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. 　　zVideo Data –Video pixel data (8b data encoded to 10b), and Guard Bands (fixed 10b pattern) 　　zData 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). 　　zControl –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. 　　zThis is exactly the same as single link DVI 1.0 　　 Also supports video rates below 25MHz e.g. 13.5MHz for 480i NTSC signals. 　　zAchieves this through a “pixel-repetition”scheme. 　　 Can handle pixel data in RGB, YCbCr(4-4-4), YCbCr(4-2-2) formats. 　　zIn 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. 　　zAccommodates 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. 　　zAVI (Auxiliary Video Information) Infoframe 　　 Communicates Colorimetry, Picture aspect ratio, Pixel-Repetition factor, RGB or YCbCrindicator, and others specified within 861B standard. 　　zAudio 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 Type A socket.

　　HDMI的规格书中规定了三种HDMI接头, 分别是:

HDMI脚位配置
HDMI AType

 Pin定义
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 CEC
14 Reserved (N.C. on device)
15 SCL
16 SDA
17 DDC/CEC Ground
18 +5V Power
19 Hot Plug Detect
HDMI B Type

　　总共有29pin, 可传输HDMI A type两倍的TMDS资料量, 相对等于DVI Dual-Link传输, 用于传输高分辨率(WQXGA 2560x1600以上)。 (因为HDMI A type 只有Single-Link的TMDS传输, 如果要传输成HDMI B type的讯号, 则必须要两倍的传输效率, 会造成TMDS的Tx、Rx的工作频率必须提高至270MHz以上。 而在HDMI 1.3 IC出现之前, 市面上大部分的TMDS Tx、Rx只能稳定在165MHz以下工作。)

Pin Pin定义
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 TMDS Data5+
14 TMDS Data5 Shield
15 TMDS Data5-
16 TMDS Data4+
17 TMDS Data4 Shield
18 TMDS Data4-
19 TMDS Data3+
20 TMDS Data3 Shield
21 TMDS Data3-
22 CEC
23 Reserved (N.C. on device)
24 Reserved (N.C. on device)
25 SCL
26 SDA
27 DDC/CEC Ground
28 +5V Power
29 Hot Plug Detect
HDMI C Type

　　总共有19pin, 可以说是缩小版的HDMI A type, 但脚位定义有所改变。 主要是用在便携式装置上, 例如DV、数码相机、便携式多媒体播放机等。 现在已有SONY HDR-DR5E DV利用此规格接头作为影像输出接口。(常常有人称为该规格为mini-HDMI, 这可算是自行胡乱创造的名称, 实际上HDMI官方并没此名称。)
HDMI D Type

HDMI Type D，俗称Micro HDMI 是定义为HDMI 1.4版本的，保持hdmi标准的19pin .但是尺寸与微型USB的接口差不多，尺寸为2.8 mm × 6.4 mm,比mini hdmi (2.42 mm × 10.42 mm)小很多，主要应用在一些小型的移动设备上，如手机，MP4等等。

　　对于手机的厂家来说，不管怎么努力，手机的屏幕还是太小，要想更多人看清，将视频输出到外部显示设备无疑是必须的，在XT800之前，已有数款机型支持AV模拟输出，通过特制3.5mm转接线来实现CVBS复合信号+立体声音频，不过这一接口最大的局限就是清晰度超低，320x240的分辨率使得这种输出仅限于比较简单的应用，况且转接线的体积都不小，使用并不方便。

　　眼看HDMI接口电视、投影机、显示器越来越多，采用HDMi接口已经成为大势所趋，标准HDMI接口分为AB两种类型，不过我们常见的都是A型口，B型口由于是双通道超宽结构基本上见不到厂家使用，标准A型口大约15mm宽，这对于家电产品自然不在话下，但在数码产品上使用显然占地方太大了，于是乎DV和DC产品普遍出现了HDMIC型口，也就是MiniHDMI接口。

　　不过对于手机而言，C型口依然有点大，于是D型口就应运而生，由于发布时间较短，到现在也不过半年时间，接口太小，对于高频率视频信号的传输、防静电要求等都比A型口要困难的多，XT800是我们首先有机会了解到的HDMID型口应用设备，而转接线就比较难找，笔者经多方面寻找，终于在淘宝上找到了一根绿联科技的D型口转A型口线材，有了它，连接电视、显示器、投影机都不再是难事。

　　一端为标准的HDMI插头，一端为Micro HDMI(D type)手机，目前部份手机有此接口。如：Motorola XT800,Nokia N8 and HTC EVO 4G 。

Pin Pin定义
1 TMDS Data2 Shield
2 TMDS Data2+
3 TMDS Data2–
4 TMDS Data1 Shield
5 TMDS Data1+
6 TMDS Data1–
7 TMDS Data0 Shield
8 TMDS Data0+
9 TMDS Data0–
10 TMDS Clock Shield
11 TMDS Clock+
12 TMDS Clock–
13 DDC/CEC Ground
14 CEC
15 SCL
16 SDA
17 Reserved (N.C. on device)
18 +5V Power
19 Hot Plug Detect

　英文定义：

　　 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.

　　zRequires separate licensing from that of DDWG’s DVI.

　　zAllows 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.

　　zSource synchronous architecture. Uses a separate channel to transmit the clock.

　　zUsed 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.

　　zDigital audio processed into packets of data

　　zThese packets are scheduled for transmission during existing horizontal and vertical blanking times within a frame.

　　 In addition, HDMI implements a packet called an infoFrame.

　　zInfoFramesare structures defined in the EIA-861B specification

　　zEIA-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.

　　zVideo Data –Video pixel data (8b data encoded to 10b), and Guard Bands (fixed 10b pattern)

　　zData 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).

　　zControl –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.

　　zThis is exactly the same as single link DVI 1.0

　　 Also supports video rates below 25MHz e.g. 13.5MHz for 480i NTSC signals.

　　zAchieves this through a “pixel-repetition”scheme.

　　 Can handle pixel data in RGB, YCbCr(4-4-4), YCbCr(4-2-2) formats.

　　zIn 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.

　　zAccommodates 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.

　　zAVI (Auxiliary Video Information) Infoframe

　　 Communicates Colorimetry, Picture aspect ratio, Pixel-Repetition factor, RGB or YCbCrindicator, and others specified within 861B standard.

　　zAudio 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