What is HDMI 2.1a?

HDMI is the most current cabling standard for video transmission between televisions, displays and other devices. With the HDMI 2.1a version, users will be more confused.

When you buy a TV, the technical specifications page tells you its resolution, whether it offers HD, FullD, 4K or 8K quality, how many HDMI inputs it has, etc. tells. But when it comes to HDMI cables, it’s not that simple. Do you know how to distinguish two HDMI cables with the naked eye? The debate goes back a long way. And with the announcement of HDMI 2.1a, the newest version of this digital video standard, beyond solving the problem, you still won’t know what type of cable you’re using.

HDMI 2.1a will be presented at CES 2022 (Consumer Electronics Show), one of the world’s largest events dedicated to consumer electronics. The good news is that like any update, HDMI 2.1a is a revision of its predecessor, 2.1, with improvements and new features. The bad news is that it will be very difficult for you to know if you have a cable with this version.

But let’s go piecemeal. What is the HDMI standard? What does HDMI 2.1a bring us better, and what arguments are there that make it practically impossible to distinguish between two HDMI cables, other than what the manufacturer or the salesman in charge tells you?

Standard for audio and video cables

HDMI stands for High Definition Multimedia Interface, High Definition Multimedia Interface in Turkish. It was introduced more or less in 2003, and since then televisions and existing devices have been interconnected using these types of connectors and cables. HDMI cables are the industry standard replacing RCA connectors and scarts.

If you have a television, Blu-Ray player, external Freeview receiver, or Xbox 360 or PlayStation 2 video game console or newer models that are less than 20 years old, you will already be familiar with HDMI cables. Thanks to them, today we enjoy high definition content from devices such as consoles, players or tuners connected to our television.

As is often the case with standards, HDMI is controlled by an international consortium that brings together the largest electronics manufacturers. In this case, it is the HDMI Forum, where more than 1,700 companies are represented. And all these years, updates to the HDMI standard have emerged from this consortium.

First it was HDMI 1.0. Then came the newest, 1.1, 1.2, 1.3, 1.4, 2.0 and 2.1. However, in the TVs, appliances, and cables market, many of these versions coexist. And one of the problems is that it is not easy to know which version of HDMI that integrates ports and cables.

What’s new in HDMI 2.1a?

HDMI 2.1a will be available at CES 2022. It is the fifteenth version of the HDMi standard, created for ports and cables to transmit audio and video, controllers, and other functions you can use in your home.

For starters, HDMI 2.1a is a revision of the 2.1 standard. Therefore, there is no change in the numbering. Apart from last minute surprises, the main innovation is the functionality called SBTM, which stands for Source-Based Tone Mapping. It is basically a development focused on HDR technology, which is one of the pillars of enjoying content in UHD or 4K.

Specifically, SBTM offers source-based tone mapping, which is a literal translation of its English acronym. What this means is that HDR tone mapping is done partially at the source of the content, whether it’s the player or the set-top box. The other part continues to make the HDR-compatible television or monitor itself, as before. It does not replace Dolby Vision or HDR10. Makes it easy to use.

Technically it sounds good. But how does it benefit you for the user? In theory, the introduction of SBTM will make it easier to enjoy HDR compatible content because you won’t have to manually set this option on your TV. Tone mapping will be almost automatic.

Another advantage of the HDMI 2.1a standard is that you don’t need to switch TVs or devices. Devices will receive this support through firmware updates. Although they don’t have to. Manufacturers will be able to include support for this standard if they wish. On the other hand, you will need an HDMI 2.1a cable to enjoy the new functionality. Here we return to the eternal problem.

Discussions about HDMI ports and cables

Although I don’t want to go too far when talking about the HDMI standard, it would be useful to make the version issue a little more specific. The HDMI standard has changed a lot between version 1.0 and the current 2.1. For starters, you can transmit 1080p content with HDMI 1.0. Support for 4K or 2160p did not exist until version 1.4 of HDMI. And that means 24 or 30 frames per second. Upscaled to 60 frames per second with HDMI 2.0. And 8K and 10K support is added with HDMI 2.1. Frame rate per second increased to 120. There are also other changes and improvements in voice and data transfer speed.

All this does not seem like a problem at first glance. The problem starts in 2012. The HDMI Forum, a consortium of companies interested in maintaining the HDMI standard, agrees that no one will talk about the HDMI version of cables and ports. They will only report the functions they support. This is the reason why it is almost impossible for us to distinguish an HDMI 1.4 cable from a 2.0 or 2.1 cable.

Normally, HDMI cables show their benefits. For example, HDMI 4K or HDMI 8K. They also usually indicate bandwidth. For example, 4K@120Hz or 4K@60Hz. Some vendors bypass this ban and tell you which version of HDMI they’re selling. We can find cables that come up with the name High Speed ​​HDMI 2.0. It provides some relief for the buyer. But once purchased, you have to look at what the cable indicates to distinguish them.