An anonymous reader shares a report: The HDMI standards are a mess. HDMI 2.1, in particular, is a uniquely frustrating mess, with haphazard support among TV manufacturers, cable makers, and devices that make setting up, say 120Hz gaming on a PS5 or Xbox Series X a uniquely harrowing experience. Fortunately, the HDMI Forum is swooping in ahead of CES with its latest revision to the HDMI specification stack, HDMI 2.1a, which is here to make everything better and simpler… I’m kidding, of course. It’s gonna make things more complicated. It’s a new HDMI standard, what on earth did you expect?
Let’s start with the good: 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. Other use cases could be for when there’s a mix of content types, like for streamers (who could have an HDR game playing alongside a window of black and white text), displaying each area of content.