What is HDMI Input Used For?

One of the most basic questions asked by those unfamiliar with the audio/video interfaces is “what is HDMI input used for?”. HDMI ports, being the most widespread interface for multimedia connectivity, can be either input or output.

HDMI input ports are generally found on display devices such as monitors, TVs and projectors. They are basically used to receive the audio and video signals from the source device such as PC, gaming consoles, set-top boxes, home theater system etc.

Again, you must note that not all HDMI ports are inputs. HDMI ports can also be output ports. It all depends upon the device in question and in the following text I will talk about this in detail.

HDMI Interface is Unidirectional

For starters, you must note that unlike interfaces used for files transfers such as USB or Ethernet Network, data in HDMI interface travels in only one direction.

In USB and ethernet networks, both the source and the destination ports can act as input or output. They have the hardware and the controllers to send and receive data (in majority of the cases).

For instance, when you connect your phone to your PC via a USB cable, you can send and receive data to and from the phone and the PC.

This is NOT how the HDMI interface works.

With the HDMI interface, the source device (output) has a different hardware for encoding and sending the data. The destination has a different hardware for decoding the data.

The following graphic shows a general idea of how the data flows in HDMI vs USB interfaces.

What is HDMI Input Used For
HDMI is a digital multimedia interface. USB is a file transfer interface (can also be used for sending A/V data)

Hence, input and output ports on an HDMI serve different purposes.

Also Read: Does My Laptop Have an HDMI Input?

So What is HDMI Input Used For?

As mentioned, the HDMI input port is used to receive the Audio/ Video signals from the source device.

For instance, in order to display an image on a monitor or on a TV the corresponding pixels have to turn on. The information regarding which pixels have to turn on and off and when is sent from the source device (i.e PC, blu-ray player).

pixels image
Close up on Pixels. Certain pixels have to turn on or off in order to show an image. This information travels from the output port on the source device to the input port on the display device. Source: Wikipedia

This information travels from the HDMI output port, through the HDMI cable and to the input port on the display device. The display device then decodes the data and responds accordingly by switching the required pixels on or off.

Dell S2421HN monitor
HDMI Input ports located on a monitor. Dell S2421HN monitor

Similarly, a typical soundbar for a home theatre system also uses an HDMI input port. It receives the audio signals from the source device and then broadcasts it as audio.

What Devices Use HDMI INPUT Ports?

So from the discussion above, it should be clear that there are two types of HDMI devices:

  • Output devices
  • Input devices

Output devices send the A/V signals out through the HDMI output port. Input devices have input ports. They receive the signals sent from the output ports and broadcast them in the form of video (monitor), audio (soundbar) or both (TV).

The following table lists the HDMI devices that use HDMI interface highlighting whether they have input or output HDMI ports.

TypeDevice
InputTV
Monitor
Projector
Soundbar
A/V Receiver
OutputDesktop
Laptop
Gaming Consoles
Blu-ray / DVD Player
Set-top Boxes
DSLR Camers
Tablets
Mobile Phones

Also Read: How to Connect Monitor with No HDMI Ports?

Some Devices Can Have Both HDMI In and Out

While most of the devices either have input or output ports, there are some devices that can feature both.

Xbox One Has Both HDMI Input and Output Ports

Take for instance some of the gaming consoles such as the Xbox One. This gaming console has both an HDMI input and an HDMI output port.

xbox one hdmi port
#2 port is HDMI output. #3 port is HDMI input. Source: Xbox One

While it makes sense to have an output port for sending the AV signals to the TV or monitor, what is the purpose of an HDMI input on a gaming console?

Input ports on source devices, such as gaming consoles, often serve specialized purposes.

The input port on Xbox one is a specialized port which was intended to connect to a set-top top for receiving cable or satellite TV. That way you could have one consolidated environment for home entertainment under one console.

However, that idea never picked up.

The HDMI input port has been ditched in the newer-gen consoles i.e in the Xbox X and Xbox S consoles.

HDMI Switches and Splitters

HDMI switch
A 1 to 2 HDMI switch.

Another set of popular devices that use input and output HDMI ports are switches and splitters. These devices basically, turn one HDMI port into multiple HDMI ports.

So basically, they have one HDMI input that receives the signals from the output HDMI port of the source device. It then, branches it into two or more HDMI output ports.

Also Read: Can I Plug HDMI 2.1 Cable Into a 1.4 Port?

Final Words

So the answer to the question “what is HDMI input used for?” is quite straightforward. An HDMI input port is used to receive A/V signals from the source device and then broadcast it to the user in the form of video signals, audio signals or both.

Also Read: Can You Add HDMI Ports to a Computer?

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Author:

Atif Qazi
Atif Qazi is the founder of PCGuide101. He is a digital nomad who loves everything PC. He is a PC builder, tech enthusiast, engineer, and a lover of single player lore-rich RPG games.

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