Here comes HDMI 2.1a, another confusing new spec for consumers

The HDMI Forum has announced its latest revision to the HDMI specification stack, HDMI 2.1a, which promises to add yet another confusing new spec for consumers.

Apple's new MacBook Pro models have HDMI 2.0, not HDMI 2.1
Apple’s new MacBook Pro models offer HDMI 2.0, not HDMI 2.1

Chaim Gartenberg for The Verge:

HDMI 2.1a is an upcoming revision to the HDMI 2.1 stack and adds a major new feature, Source-Based Tone Mapping, or SBTM. SBTM is a new HDR feature that offloads some of the HDR tone mapping to the content source (like your computer or set-top box) alongside the tone mapping that your TV or monitor is doing.

SBTM isn’t a new HDR standard — it’s not here to replace HDR10 or Dolby Vision. Instead, it’s intended to help existing HDR setups work better by letting the content source better optimize the content it passes to the display or by removing the need to have the user manually calibrate their screens for HDR by having the source device configure content for the specific display…

It seems virtually guaranteed that in the majority of cases, users won’t be getting the new features until they buy a new TV that supports HDMI 2.1a right out of the box (which, as of now, is precisely zero of them, given that the spec has yet to be fully released).

Now here’s the bad: like every other unique HDMI 2.1 feature, including variable refresh rates, automatic low latency connections, and the bandwidth necessary to offer things like 10K resolution or 120Hz refresh rates, SBTM will be an optional feature that manufacturers can support — but not something that they’re required to support…

That leaves the upcoming HDMI 2.1a standard and its new SBTM feature in much the same place as the rest of HDMI 2.1 and its feature set: a potentially helpful new feature that could make the content you watch and play look better, but that will likely require buying new hardware and cables, and which may not even be actually supported by devices that claim to have “HDMI 2.1a” ports.

MacDailyNews Take: Before you buy, always read the fine print to see exactly which HDMI features are actually included in the TV or device you’re considering.

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  1. “which may not even be actually supported by devices that claim to have “HDMI 2.1a” ports”

    If it doesn’t include a feature of the standard, how can it be labeled as the standard?

    1. Because almost all of the new “standards” are not really standards. They are a set of optional features, which may exist in concert. They are called standards because what used to be standards bodies are still overseeing this set of optional features. The likelihood of all of the optional elements existing in a single port is virtually zero.

      This is what “standards” have come to these days. It does not matter whether you are referring to USB 4 protocols or USB Type-C connectors or DisplayPort or HDMI. All of them have so many options that it is virtually impossible to tell exactly what the device’s port supports or what is the best cable to use.

      1. A well made point.

        I’ve been out of the market for awhile on Monitors, but in getting spun up for a new system, I’m in the middle of discovering just what a {bleeping} mess the HDMI “not Standards” are.

        Not too much unlike USB-3 / 3.1 / 3.2 / 4 / whatever … its a paralyzing nightmare of not quite being sure just which combination does what, and with which cable/etc.

        What I do know is just like my USB-C / Thunderbolt cables, I’m going to manually color code and mark every last one of them with what their specifications are, to try to minimize this being cluster-mess later….

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