Just when one thought HDMI standards had settled down, the HDMI Forum have decided to use what’s left of CES 2022 to introduce yet another standard – HDMI 2.1a.
The reality is that HDMI standards are a mess, with the move to 2.1 creating problems for a lot of manufacturers, especially gaming machine and console manufacturers.
The HDMI Forum claim that HDMI 2.1a introduces a major new feature, called 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 is not 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 optimise 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.
The HDMI Forum claims it’ll be possible for set-top box, gaming companies, and TV manufacturers to add support through firmware updates for HDMI 2.1a and its source-based tone mapping “depending upon their design”.
The Verge claims that given the usual trajectory of TV spec updates, though, 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.
And that could be a long way off because SBTM will be an optional feature that manufacturers can support — but not something that they’re required to support.
That’s because the HDMI Forum and HDMI Licensing Administrator (the two organisations that define and license out HDMI standards, respectively) run the standards as a set that contains all the previous standards.
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.
It will be interesting to see how many of the new CES 2022 TVs have the new HDMI standard.
