HDMI Forum will introduce HDMI 2.1a, the latest standard, at CES 2022, with minor updates that only further complicate the system's haphazard device support

Brace yourself for yet another new HDMI standard — The HDMI standards are a mess. HDMI 2.1, in particular, is a uniquely frustrating mess …

The Verge 2021-12-30 Chaim Gartenberg

Context & Ripple Effects

HDMI 2.1 began as a feature-heavy specification, adding 48Gbps bandwidth, higher-resolution modes, VRR, and Dynamic HDR. HDMI 2.1a turns that already broad capability set into another version buyers and device makers must parse against uneven implementation.

The later record reinforces that versioning did not simplify the ecosystem: the Forum went on to introduce HDMI 2.2 and its required Ultra96 cable, while restricting public specification access and rejecting AMD's open-source implementation proposal.

First-order effects

The HDMI Forum adds HDMI 2.1a to the naming stack, making a version label still less reliable as a shorthand for which HDMI features a device supports.
Device makers and buyers must compare supported capabilities rather than assume that products carrying adjacent HDMI version labels behave alike.

Second-order effects

Manufacturers and retailers face greater pressure to state feature-level support clearly, because the HDMI label alone no longer resolves compatibility questions.
AMD's blocked open-source implementation means developers cannot use a public HDMI 2.1 reference to reduce those implementation differences.

Third-order effects

If successive HDMI revisions continue to arrive alongside uneven support, interoperability competition shifts from the connector name to how clearly vendors document and implement individual features.
The Forum's closed-specification posture, highlighted by its rejection of AMD's open-source HDMI 2.1 proposal, concentrates influence over compatibility in the standards body's licensing and governance choices.

The trend: HDMI is evolving into a feature-by-feature compatibility market, where version numbers and access to specifications increasingly shape interoperability.

Discussion

@rstephens Robert Stephens on x
Geek Squad will never go out of business. https://twitter.com/...
@idlesloth84 Idle Sloth on x
Source-Based Tone Mapping 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. TV manufacturers to add support through firmware updates for HDMI 2.1a …
@samitsarkar Samit Sarkar on x
lmao what “... once the standard is released, by the HDMI Licensing Administrator's rules, all new ports will, in theory, be labeled HDMI 2.1a — but they won't have to offer the new SBTM or even any HDMI 2.1 features.” https://twitter.com/...
@rjcc Richard Lawler on x
HDMI 2.1again, because the first try was a mess https://www.theverge.com/...
@bdsams Brad Sams on x
The “a” stands for “absolutely no one will understand this” https://twitter.com/...
@nut_bunnies @nut_bunnies on x
HDMI turning into USB sucks. Used to be the one cable you could say “just get any of them” to non-techies https://twitter.com/...
@tha_rami Rami Ismail on x
HDMI remains short for “Hot Damn Mess, Innit”? https://twitter.com/...
@edzitron Ed Zitron on x
Fantastic news! I needed a new hdmi standard. I was too comfortable https://twitter.com/...
@backlon Dieter Bohn on x
What a fiasco. Everybody in charge of these spec naming conventions should be required to spend two hours explaining their proposed spec to the public at Beat Buy for every one hour they spend in committee coming up with this nonsense. https://www.theverge.com/...

Chronicles