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What is an HDMI dummy plug? I read the description, but didn’t get it. What does it do?

• js2 3y ago
  It makes the source think there is a display connected by responding with an EDID block. It may also handle the HDCP negotiation but I'm not sure about that. Technically an unlicensed device isn't supposed to be able to implement HDCP so while the Chinese manufacturers are totally willing to skirt around that, they also don't go advertising it.
  • walteweiss 3y ago
    But why would one need it? I don’t get get idea behind it, what’s with me having a fake extra display? Is it somehow tricks the DRM or what?
    • js2 3y ago
      The primary use case I'm aware is for headless computing. Re-reading what ladzoppelin wrote, I made an assumption that was probably incorrect. I thought they were saying that having an HDCP-compliant TV attached allowed them to watch DRM-protected content on their non-HDCP-compliant primary display. But in retrospect, probably they are watching the DRM content on the TV. In that case they don't need an HDMI dummy plug at all. They could instead use the splitter I linked between their computer and the non-HDCP compliant display (assuming it's connected over HDMI and not DisplayPort) to fool their computer into thinking the display is HDCP-compliant. Then they can play the DRM content on either their primary display or the TV.
      • walteweiss 3y ago
        Thank you for your explanations!