In today's digital entertainment world, HDMI is the primary physical connection used to transfer audio/video signals between devices. Let's dig into the details of HDMI by discussing the following:

Skip to section

What HDMI Is

HDMI is the primary connection used for physically transferring video and audio signals digitally from a source to a video display using a single cable. The letters HDMI mean High Definition Multimedia Interface.

Examples of home entertainment devices that may have HDMI connections are:

• DVD (Upscaling players)/Blu-ray/UHD HD Blu-ray players
• Media streamers (Roku, Fire TV, Chromecast, Android TV, Apple TV, etc...)
• HD cable/satellite boxes and DVRs
• Select Smartphones.
• Digital cameras/camcorders
• Many Desktop/Laptop PCs
• Most Game consoles
• TVs, video projectors, and PC monitors.
• Home theater receivers, home-theater systems, and soundbars

HDMI Version History

HDMI is an evolving standard and there have been several versions released over time since its introduction in 2002. The HDMI version implemented on a device depends on when it was purchased. 

Each newer HDMI version includes the features of previous versions. However, newer version features can't be accessed if your device(s) are optimized for an older version.

Manufacturers can also pick features they want from the HDMI version they choose to include in a product. This means if a product uses a specific version, not all of the features of that version may be available. 

The following is a summary of the HDMI versions released so far with their month/year of introduction and core features.

HDMI 1.0 (December of 2002): Digital video resolution up to 1080p, Dolby Digital, DTS, and up to 7.1 channel uncompressed PCM audio support.

HDMI 1.1 (May 2004): Adds DVD Audio Support.

HDMI 1.2 (August 2005): Adds SACD audio support and HDMI-CEC (discussed in detail later in this article).

HDMI 1.3 / 1.3a (June 2006): 

• Adds Deep Color and faster transfer speed (up to 10.2 Gbps) support for Blu-ray Disc and HD-DVD.
• Support for video resolutions between 1080p and 4K.
• Adds Dolby Digital Plus, Dolby TrueHD, and DTS-HD Master Audio surround sound support.

• Automatic Lip sync.
• Introduction of Mini-HDMI (Type C) connector option.

HDMI 1.4 / 1.4a / 1.4b (2009): 

• Adds Audio return channel (ARC)
• 3D over HDMI
• HDMI Ethernet channel
• 4K resolution (30-Hz frame rate) 
• Introduction of HDMI Micro and Automotive connectors.

HDMI 2.0 (September 2013):

• 4K video with 50- or 60-hertz frame rates.
• Up to 18 Gbps transfer rate with 8-bit color.
• Support for Dolby Atmos, DTS:X, and Auro 3D Audio (up to 32-channels total). 
• Support for viewing two independent video streams on the same screen.
• Support for four separate audio streams.
• 21:9 (2.35:1) aspect ratio support.
• Dynamic video and audio stream synchronization.
• HDMI-CEC feature extension.
• Upgraded HDCP support (ver 2.2).

HDMI 2.0a (April 2015): Adds HDR support (HDR10 and Dolby Vision).

HDMI 2.0b (March 2016): HDR support expanded to Hybrid Log-Gamma (HLG) format. 

HDMI 2.1 (November 2017)

• Support for 4K, 5K, 8K, and 10K resolutions at 50/60/100/120 Hz.
• BT2020 Wide color gamut support, at 10, 12, and 16 bits.
• eARC (Enhanced Audio Return Channel) introduced.
• Variable refresh rate (VRR) Gaming Support 
• Bandwidth capability increased to 48 Gbps (requires compatible cable).

HDCP

The HDMI standard includes HDCP (High-bandwidth Digital Copy Protection). This prevents content from being illegally copied through devices connected using HDMI connections. The latest HDCP version is 2.2.

The way HDCP works is that each device in the HDMI connection chain has to recognize each other via "handshake". If the handshake doesn't occur, it means that HDCP encryption isn't recognized by one or more of the connected devices. This prevents access to content passed through the HDMI connections.

However, false HDCP handshake errors may occur in some HDMI connection setups. This can often be fixed by following some easy steps.

HDMI-CEC

HDMI-CEC (Consumer Electronics Control) gives the ability of HDMI to pass some remote control commands back and forth between compatible devices. 

This means that through an HDMI connection, you can use a TV remote to control some functions of a Blu-ray Disc player, home theater receiver, soundbar, or another compatible audio system, or you may be able to control the TV using the audio system's remote. 

In addition, if you turn one of the devices on or off, other devices connected with HDMI-CEC activated will do likewise at the same time. 

When using HDMI-CEC, keep the following in mind:

• Not all HDMI-CEC features may be implemented in a specific product. 
• Some TVs and AV Receivers require that HDMI-CEC be enabled for the HDMI-ARC feature to work. 
• Specific manufacturers may have a different label for this feature. Some examples include LG Simplink, Sony Bravia Link or Bravia Sync, Panasonic Viera Link, Sharp Aquos Link, and Samsung Anynet+. 

Check the user guide of your device for the designated label, set up, and use details.

HDMI and MHL

Another feature that HDMI is able to incorporate is MHL (Mobile High-Definition Link).

Smartphones, tablets, and other select devices that are MHL-enabled can connect to select TVs or home theater receivers with an MHL-labeled HDMI input (an adapter may be needed between the phone and the TV or receiver). 

Just as with HDMI, there are several versions of MHL which will dictate what audio and video formats and resolutions are compatible.

HDMI and Ethernet

HEC (HDMI Ethernet Channel) was added in version 1.4. If applied, both Ethernet and HDMI functions are available within a compatible HDMI cable connection.

This capability is rarely implemented as Wi-Fi has become the more popular method of connecting devices to the internet. However, HDMI can be used in conjunction with separate Ethernet cables (via converters) not to connect to the internet but to extend the HDMI signal transfer range using physical connections. Ethernet is more robust for transferring audio and video signals over a long distance than straight HDMI.

HDMI Cable Categories

There are several official HDMI cable categories:

Standard HDMI Cable: For use with HDMI versions 1.0 to 1.2a. Video resolutions up to 720p and 1080i, bandwidth capacity up to 5 Gbps. 

High-Speed HDMI Cable: For use with HDMI versions up to 1.3 to 1.4a. Video resolutions of 1080p and 4K (30Hz), 3D, and Deep Color support. Bandwidth support up to 10 Gbps. 

Premium High-Speed HDMI Cable: For use with HDMI versions up to 2.0/a/b. Supports transfer of 4K/60 Hz video, HDR, and expanded color range. Bandwidth support up to 18 Gbps. 

Ultra High-Speed HDMI Cable: For with HDMI versions up to 2.1. Supports transfer up to 8K resolution with HDR. Bandwidth up to 48 Gbps. Minimization of EMI (electromagnetic interference). 

Standard and High-Speed HDMI cables with built-in Ethernet Channel.

Standard and Hi-Speed Automotive HDMI Cables: Supports connection of portable or in-car DVD players and other devices to in-car video displays. Extra shielding is included to minimize interference from other car electrical systems.

HDMI Cable Connectors

Type A (Standard size): This connection is typically used in TVs, video projectors, DVD/Blu-ray/Ultra HD players, media streamers, cable/satellite boxes, video game consoles, and home theater receivers. 

Type C (Mini size): This connection is primarily used on DSLR cameras. One end of a Type C cable usually has a standard size connector that plugs into a TV, PC monitor, or video projector. 

Type D (Micro size): Micro HDMI is used on smaller portable devices such as compact digital cameras, smartphones, and tablets. Typically, the cable has a micro connector on one end and a Type A connector on the other.

Type E (Automotive): This is the connection used automotive HDMI AV applications.

NOTE: There is no HDMI Type B connector currently in use.

Wireless HDMI

HDMI signals can also be transferred wirelessly, usually at a distance of 30-to-60 feet, but some transmitters provide up to a 150-foot range.

Wireless HDMI works by using a short HDMI cable from the output of a source (Blu-ray Player, Media Streamer, Cable/Satellite Box) to an external transmitter. The transmitter then sends the embedded HDMI signal(s) wirelessly to a receiver that is connected to a TV or video projector using a short HDMI cable.

WHDI and Wireless HD (WiHD) are the two wireless HDMI systems in use.

• WHDI transmits HDMI signals in the 5 GHz frequency band with a range of 100 feet or more (depending on the product). Brands that support WHDI include IOGEAR and Nyrius.
• WiHD transmits HDMI signals in the 60 GHz frequency band with a range of about 60 feet. Line-of-sight-transmission yields the best results as the range is decreased or is prevented when going through walls. Brands that support WiHD include DVDO and Monoprice

There are differences with respect to which HDMI version and features (video resolution, audio formats, etc...) are supported on specific Wireless HDMI products. Check the features and specifications of the specific "wireless HDMI" product you are considering.

HDMI ARC/eARC

HDMI ARC (aka Audio Return Channel) was introduced in HDMI ver 1.4. It simplifies sending audio from a TV to an external audio system. 

Audio Return Channel allows the HDMI cable connected to a TV and compatible audio system to transfer audio in both directions.

If a TV supports HDMI-ARC, sources connected directly to the TV via HDMI, antenna, internet, and analog inputs can display the video portion on the TV screen but send the audio portion out through the HDMI cable connected from the TV to a compatible external audio system. 

If available on a TV or audio system, HDMI-ARC connections should be clearly labeled. 

HDMI-ARC supports the transfer of Dolby Digital, Dolby Digital Plus, and DTS 5.1 bitstreams that can be decoded by an external audio system, as well as two-channel PCM. However, access to specific formats is provided at the manufacturer's discretion. Check your TV's user guide for details.

A newer version of ARC, eARC (Enhanced Audio Return Channel), is available as part of HDMI ver2.1. eARC adds the ability to transfer higher-resolution Dolby TrueHD/DTS HD-Master Audio, Dolby Atmos, and DTS:X bitstreams, as well as 5.1/7.1 channel uncompressed PCM audio. 

On eARC-enabled TVs, any audio originating from the TV or from any source connected to the TV can be transferred to an eARC compatible external audio system via one HDMI cable connection, provided the TV manufacturer implements all of the eARC features.

HDMI vs Digital Optical/Coaxial

Another commonly used digital audio connection, in addition to HDMI, is Digital Optical/Coaxial. You may find both digital optical/coaxial connections on many devices but digital coaxial connections are not provided on TVs. 

Digital audio signals that can be transferred by digital optical/coaxial connections include two-channel stereo PCM, Dolby Digital/Dolby Digital EX, DTS Digital Surround, and DTS ES.

Surround sound formats that require extra bandwidth, such as 5.1/7.1 multi-channel PCM, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, DTS:X, Auro 3D Audio, SACD (DSD), and DVD-Audio need HDMI connections to transfer the audio signals. HDMI is also able to transfer all the audio formats that digital optical/coaxial connections can. 

NOTE: There is a difference as to which formats can be transferred when using the HDMI-ARC and HDMI-eARC connection options between a TV and an audio system. 

Managing HDMI Connections Through Your TV 

You can use HDMI for both video and audio with a TV in several ways.

ONE: You can connect all your HDMI source devices to your TV and watch the video and listen to the audio using the TV.

TWO: You can connect all HDMI source devices to your TV and then connect the TV to an external audio system using analog or digital optical outputs connected to an external audio system. This allows you to watch the video on your TV and hear the audio on an external audio system. 

THREE: You can connect all HDMI source devices to a home theater receiver, then connect the HDMI output of the home theater receiver to the TV. Just as in the previous setup, you will be able to watch the video from sources on the TV and hear the audio portion on the speakers connected to the home theater receiver. 

FOUR: If your TV and home theater receiver are both HDMI-ARC (Audio Return Channel) compatible, you can connect HDMI sources to the TV and then plug the HDMI cable connected to your TV’s "HDMI-ARC" or "Audio Return Channel" labeled HDMI port to the HDMI output on your Home Theater receiver that is also labeled "HDMI-ARC". 

This allows you to watch videos from sources connected to the TV and hear the audio from the TV on your Home Theater Receiver. In addition, for any sources also connected to the home theater receiver, the same HDMI-ARC labeled output on the home theater receiver will send the video from those sources to the TV, but let you hear the audio on the wired speakers connected to the receiver. 

However, instead of using a home theater receiver with wired speakers, you use an Enclave Audio CineHome II or THX-Certified CineHome Pro WiSA enabled audio system that uses wireless speakers. You connect all your sources to the TV and then connect the TV's HDMI-ARC connection to the HDMI-ARC connection on the Enclave Audio System's CineHub. The CineHub performs any additional needed audio processing and sends the sound to the speakers and subwoofer wirelessly.