HDMI Forum Rejects Open-Source HDMI 2.1 Driver Support Sought by AMD

Original Article ↗ Hacker News Discussion ↗

HDMI’s industry consortium has barred AMD from releasing open-source Linux drivers for HDMI 2.1, highlighting how access to the latest HDMI features is controlled through NDAs, licensing fees, and legal risk. Commenters argue this entrenches proprietary, anti-consumer behavior, complicates Linux support for modern TVs and AV gear, and may even raise antitrust concerns. Many see the move as a reason to favor DisplayPort and USB‑C alternatives, despite HDMI’s dominance in televisions and home theater equipment.

Legal / Contractual Barriers

  • Posters say AMD cannot “just ship” an open HDMI 2.1 driver because:
    • HDMI is both a proprietary spec and a trademark; use requires forum approval.
    • Members sign NDAs and contracts that likely forbid releasing an open driver.
    • Violations could mean lawsuits, damages, and expulsion from the forum.
  • Some argue losing HDMI/codec patent-pool access could jeopardize major businesses (e.g., console design wins, hardware decode of popular codecs).

Workarounds, Hacks, and Clean-Room Ideas

  • Suggestions include:
    • Unofficial third‑party patches to OSS drivers, possibly hosted in jurisdictions with weaker IP enforcement (France, China, Russia).
    • “Mystery port” or renamed HDMI connectors to avoid trademark issues.
    • Reverse engineering or spec leaks, but people warn about legal “taint” that can block contributors from future clean-room work.
  • Skepticism that DMCA/HDMI Forum could fully scrub such patches from the Internet, but they could make life difficult for maintainers.

DisplayPort vs HDMI

  • Strong sentiment that users should prefer DisplayPort:
    • Royalty‑free, technically similar or better, higher bandwidth (DP 2.x vs HDMI 2.0 limits on PCs).
    • Runs over USB‑C via DP Alt Mode and Thunderbolt; HDMI Alt Mode is effectively dead.
  • Counterpoints:
    • TVs and AV receivers almost never include DP; many laptops and small devices are HDMI‑only.
    • Some home‑theater features (ARC/eARC, CEC) are deeply tied to HDMI; DP can technically emulate them but lacks ecosystem and standards.
  • Debate over DSC compression: marketed as “visually lossless,” but some worry about artifacts; others report no visible issues and note reliability improvements.

Linux, Gaming, and Adapters

  • Linux gamers with 4K120 HDR TVs feel locked into Windows or proprietary drivers.
  • HDMI 2.0 can do 4K120 only with chroma subsampling (4:2:0 8‑bit), which noticeably harms text rendering and desktop use.
  • Active DP→HDMI dongles exist and can provide high resolutions/refresh rates, but:
    • VRR/FreeSync support is often missing.
    • Extra adapters add cost and points of failure.

Anti-Consumer / Antitrust Concerns

  • Many view the HDMI Forum’s stance as anti‑consumer, anti‑competitive rent‑seeking, driven by HDCP and recurring licensing revenue.
  • Some call for antitrust or regulatory intervention (especially in Europe/FTC), likening this to cartel behavior.
  • Others doubt Linux support or user backlash will significantly affect HDMI adoption, given consumer indifference and TV market inertia.

Hobbyist Uses and Overlay Devices

  • Several lament that legal/HDCP barriers prevent simple, cheap HDMI overlay boxes (e.g., to display chat/text on TV video).
  • Existing solutions (pro gear, capture cards + OBS, FPGA projects, HDCP‑stripping splitters) are possible but often costly, fragile, or legally gray.