During the CES 2022 exhibition, the HDMI Licensing Administrator organization confirmed that it will release an upgraded version of the HDMI 2.1a standard specification.

The most noteworthy aspect of this specification is the introduction of Source-Based Tone Mapping (SBTM for short), that is, source-based tone mapping, which can enhance and optimize HDR display. But for consumers, the new specification may make it more complicated for users to buy HDMI cables.

According to the official introduction, the SBTM function will allow different windows to display SDR and HDR content at the same time, such as picture-in-picture or window-playing video. The SBTM function can automatically generate an optimized HDR signal to make better use of the HDR function of the display, and does not require the user to manually set it, which can improve the PC gaming experience. Judging from the official comparison chart, SBTM eliminates the overexposed part, making the details look more vivid.

The new specification replaces the old version of HDMI 2.1 specification launched in 2017. However, there is almost no change for customers, and it is still very difficult to purchase cables.

The HDMI Forum stated that this update can be added through the device's firmware update. Hardware manufacturers may wait to introduce this specification in new products. The HDMI Forum stated that manufacturers do not need to adopt new features in order to label products with the latest specifications.