What is HDMI ?

HDMI (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.


There are four types of HDMI connector. Type A/B are defined in the HDMI 1.0 specification, type C is defined in the HDMI 1.3 specification, and type D/E are defined in the HDMI 1.4 specification.

Type A

The plug (male) connector outside dimensions are 13.9 mm × 4.45 mm, and the receptacle (female) connector inside dimensions are 14 mm × 4.55 mm. There are 19 pins, with bandwidth to carry all SDTV, EDTV, HDTV, UHD, and 4K modes. It is electrically compatible with single-link DVI-D.

Type B

This connector is 21.2 mm × 4.45 mm and has 29 pins, carrying six differential pairs instead of three, for use with very high-resolution displays such as WQUXGA (3840×2400). It is electrically compatible with dual-link DVI-D, but has not yet been used in any products. With the introduction of HDMI 1.3, the maximum bandwidth of single-link HDMI exceeded that of dual-link DVI-D. As of HDMI 1.4, the pixel clock rate crossover frequency from single to dual-link has not been defined.

Type C

This Mini connector is smaller than the type A plug, measuring 10.42 mm × 2.42 mm but has the same 19-pin configuration. It is intended for portable devices. The differences are that all positive signals of the differential pairs are swapped with their corresponding shield, the DDC/CEC Ground is assigned to pin 13 instead of pin 17, the CEC is assigned to pin 14 instead of pin 13, and the reserved pin is 17 instead of pin 14. The type C Mini connector can be connected to a type A connector using a type A-to-type C cable.

Type D

This Micro connector shrinks the connector size to something resembling a micro-USB connector, measuring only 5.83 mm × 2.20 mm For comparison, a micro-USB connector is 6.85 mm × 1.8 mm and a USB Type-A connector is 11.5 mm × 4.5 mm. It keeps the standard 19 pins of types A and C, but the pin assignment is different from both.


Main specifications

 HDMI Version
Release DateDec 2002 (1.0)

May 2004 (1.1)

Aug 2005 (1.2)

Dec 2005 (1.2a)
Jun 2006 (1.3)

Nov 2006 (1.3a)
Jun 2009 (1.4)

Mar 2010 (1.4a)

Oct 2011 (1.4b)
Sep 2013 (2.0)

Apr 2015 (2.0a)

Mar 2016 (2.0b)
Nov 2017
Signal Specifications 
Max. Transmission Bit Rate4.95 Gbit/s10.2 Gbit/s10.2 Gbit/s18.0 Gbit/s48.0 Gbit/s
Max. Data Rate3.96 Gbit/s8.16 Gbit/s8.16 Gbit/s14.4 Gbit/s42.6 Gbit/s
Max. TMDS Character Rate165 MHz340 MHz340 MHz600 MHzN/A
Data Channels33334
Encoding Scheme






Compression----DSC 1.2

Color Format Support 
Y′CBCR 4:4:4YesYesYesYesYes
Y′CBCR 4:2:2YesYesYesYesYes
Y′CBCR 4:2:0NoNoNoYesYes
Color Depth Support 
8 bpc (24 bit/px)YesYesYesYesYes
10 bpc (30 bit/px)YesYesYesYesYes
12 bpc (36 bit/px)YesYesYesYesYes
16 bpc (48 bit/px)NoYesYesYesYes
Color Space Support 
SMPTE 170MYesYesYesYesYes
ITU-R BT.601YesYesYesYesYes
ITU-R BT.709YesYesYesYesYes
Adobe RGB (1998)NoNoYesYesYes
ITU-R BT.2020NoNoNoYesYes
Audio Specifications 
Max. Sample Rate Per Channel192 kHz192 kHz192 kHz192 kHz192 kHz
Max. Aggregate Sample Rate??768 kHz1536 kHz1536 kHz
Sample Size16–24 bits16–24 bits16–24 bits16–24 bits16–24 bits
Maximum Audio Channels8883232
HDMI Version