One of the most fundamental questions asked by those unfamiliar with audio/video interfaces is, “what is HDMI input used for?”. HDMI ports, 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 receive audio and video signals from a source device such as a PC, gaming console, set-top box, home theater system, etc.
Again, I’d like to point out that not all HDMI ports are inputs. HDMI ports can also be output ports. It all depends upon the device in question, and I will discuss this in detail in the following text.
HDMI Interface is Unidirectional
For starters, you must note that unlike interfaces used for file transfers, such as USB or Ethernet Networks, data in the HDMI interface travels in only one direction.
The source and destination ports can act as input or output in USB and ethernet networks. They have the hardware and the controllers to send and receive data (in most 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 different from how the HDMI interface works.
With the HDMI interface, the source device (output) has different hardware for encoding and sending the data. The destination has additional hardware for decoding the data.
The following graphic shows a general idea of how the data flows in HDMI vs. USB interfaces.
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 receives the Audio/ Video signals from the source device.
For instance, the corresponding pixels must turn on to display an image on a monitor or TV. The information regarding which pixels must turn on and off and when is sent from the source device (i.e., PC, blu-ray player).
This information travels from the HDMI output port, through the HDMI cable, to the display device’s input port. The display device then decodes the data and responds accordingly by switching the required pixels on or off.
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 them 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 interfaces, highlighting whether they have input or output ports.
| Type | Device |
|---|---|
| Input | TV |
| Monitor | |
| Projector | |
| Soundbar | |
| A/V Receiver | |
| Output | Desktop |
| 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, some devices can feature both.
Xbox One Has Both HDMI Input and Output Ports
For instance, some gaming consoles, such as the Xbox One. This gaming console has both an HDMI input and an HDMI output port.
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 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., the Xbox X and Xbox S consoles.
HDMI Switches and Splitters
Another set of popular devices that use input and output HDMI ports are switches and splitters. These devices turn one HDMI port into multiple HDMI ports.
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 relatively straightforward. An HDMI input port receives A/V signals from the source device and then broadcasts them to the user in video, audio, or both signals.
Also Read: Can You Add HDMI Ports to a Computer?
