8 Replies Latest reply on Nov 16, 2017 1:34 PM by Intel Corporation

    Driver issue: Full Quantization Range (0-255) not available with Displayport->HDMI adapter

    Ted3

      I'm using Intel HD Graphics 630 via active Displayport->HDMI 2.0 adapter (because Intel chipsets don't natively support HDMI 2.0 yet), but there's no way to output 0-255 Full RGB Range even though it works when using HDMI.

      This is because the Quantization Range setting in Intel HD Graphics Control Panel is not visible when using the adapter.

      (I tried enabling EnableRGBFullRange = 1 in registry & changing display type from TV to Digital Monitor with CRU but this doesn't help either.)

       

      It's an Intel driver issue since RGB Full Range works fine when the adapter is used with Nvidia GPU Displayport.

       

      Steps to reproduce this bug:

      1) Get an active Displayport->HDMI adapter such as CAC-1070.

      2) Enable iGPU in bios and plug a HDMI Display into a Intel motherboard using the DP-HDMI adapter.

      3) Make sure your display expects 0-255 and notice iGPU is outputting 16-255 (full black looks gray in e.g. desktop). (on LG TVs the setting "Black Level = High" means the display expects 0-255.) Notice the "Quantization Range" setting in Intel HD Graphics Control Panel is not available.

       

      Optional steps to confirm the bug:

      A) Uninstall Intel HD Graphics driver and reboot, notice black is proper black with the basic Microsoft display driver until Windows automatically updates & installs Intel HD Graphics driver.

      B) If your Intel motherboard also has an HDMI output, remove the adapter and connect the display to HDMI (use 4K 30Hz signal or lower), enable Full Quantization Range in the Intel HD Graphics Control Panel and notice iGPU correctly outputs 0-255 as black is now proper black.

      C) Connect the DP-HDMI adapter to a Nvidia GPU Displayport and enable full RGB range in Nvidia Control Panel, notice black is proper black.

       

      Suggested fix:

      Enable "Quantization Range" setting also when a Displayport->HDMI adapter is used.

       

      A temporary/manual solution would be appreciated too. (Manually putting MP_QuantRange_32623 = 2 in registry doesn't help as for some reason the value isn't read/used when the DP->HDMI adapter is used.)

       

      My motherboard is Asus IX Hero Z270 and my CPU is Kaby Lake i5-7600k with HD Graphics 630. My DP->HDMI adapter is Club3D CAC-1070 which fully supports RGB 0-255 4:4:4 4K 60Hz HDCP 2.2. My display is LG OLED55B7V.

      I'm using the latest Windows 10 1709 (16299.19) & Intel HD Graphics driver 22.20.16.4815. The same issue happens with drivers 22.20.16.4749 & 23.20.16.4819.

       

      Here you can see my Intel HD Graphics Options and Support Information Center info .txt export file: ybin | private paste