HDMI (High-Definition Multimedia Interface)
HDMI uses dual-link resolutions using a standard HDMI cable. It provides higher motion-picture frame rates and digital audio. The cables support an optional Consumer Electronics Control (CEC) feature. It allows transmission of signals from a remote-control unit to control multiple devices without separate cabling to carry infrared signals. It is used to transfer video and audio to computer monitors, digital TVs, and DVD or Blu-ray players.
In June 2006, a new specification of HDMI as 1.3 was released. It is designed to support the bit rates necessary for HD DVD and Blu-ray discs. It also supports ‘deep colour’ or colour depths of at least one billion colors, including 30-, 36-, and 48-bit colour.
But, when version 1.4 released on May 28, 2009, it was designed to support the HDMI capability for the controlling system to relay Ethernet frames between its connected components. Both Standard and High Speed cables support this Ethernet channel, but the device must support the HDMI Ethernet Channel specification.
Version 1.4 also supported 3D support and 4K resolution only at 30Hz refresh rate. It also introduced the anti-vibration Type E locking connector. Version 2.0 of HDMI was introduced in 2013. It supports the increasing 4K refresh rate to 60Hz, a 21:9 theatrical widescreen aspect ratio, and 32-channel audio.
Version 2.0a which was released in 2015 added the feature of high dynamic range (HDR) video.
There are two types of HDMI cables: Standard and High Speed. Standard cables support 720p resolution and 10801 resolutions. High Speed cables can support 1080p resolution and the newer 4K and 3D technologies. Figure 12 shows an HDMI port and connector.
The type A connector has 19 pins and is backward compatible with DVI. It is used on TVs and home theatres. The type B connector has 29 pins, and is not backward compatible with DVI. Type C connectors are a smaller version of Type A for portable devices. They are also known as mini-HDMI. Type D is an even smaller micro version that resembles a micro- USB connector. Type E is planned for use in automotive applications.