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.
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.
Please help support MacDailyNews. Click or tap here to support our independent tech blog. Thank you!