HTPC HDR Washed-Out Colors – Troubleshooting Summary
Hardware
HTPC
Windows PC (always on as a Plex server)
NVIDIA GeForce RTX 5070 (Blackwell)
NVIDIA Studio Driver 610.62
AV Receiver
Denon X4800H
Display
LG OLED65C4 OLED TV
HDMI Wiring
HTPC (RTX 5070)
│
▼
Denon X4800H
HDMI 4 (Game 1)
│
▼
Denon Monitor 1 (HDMI)
│
▼
LG C4 HDMI 1 (ARC/eARC)
Software
Windows 11
MPC-BE x64
madVR HDR beta renderer
LAV Filters
Windows HDR = OFF
madVR performs HDR switching automatically
Normal HDR Operation
During successful playback:
Windows desktop is SDR.
MPC-BE opens HDR movie.
madVR switches display to HDR.
LG displays HDR badge.
TV changes to HDR Filmmaker Mode.
HDR picture looks correct.
Failure Mode
Intermittently:
LG displays HDR badge.
TV switches into HDR Filmmaker Mode.
madVR reports HDR.
Windows behaves as though HDR output is active.
However:
Entire image becomes washed out.
Desktop is washed out.
Video is washed out.
Colors appear low contrast and desaturated.
When HDR playback stops:
TV exits HDR.
Desktop immediately returns to normal SDR colors.
Important Observations
SDR is always correct
Windows desktop looks perfect.
Only HDR mode is affected.
TV recognizes HDR correctly
The TV always reports:
HDR badge
HDR Filmmaker Mode
Therefore HDR signaling is occurring.
Desktop is also washed out
Not just the movie.
This strongly suggests the issue occurs somewhere in the HDR output pipeline rather than only in madVR’s video rendering.
Windows reboot fixes it
Restarting Windows immediately restores proper HDR operation.
This suggests some state inside the Windows display stack or NVIDIA driver is reset by rebooting.
Startup timing affects behavior
Successful sequence:
TV ON
Wait ~30 seconds
Denon ON
Wait ~30 seconds
HTPC is already running and desktop appears automatically
Start HDR movie
HDR works correctly
This points toward HDMI negotiation timing influencing the problem.
Settings Verified
Windows
HDR OFF
Desktop SDR
NVIDIA
Output configured as:
RGB Full
10-bit
Multiple output format variations have been tested previously without permanently resolving the issue.
madVR
Returned to known-good baseline:
Delay playback until renderer queue is full ✔
Use Direct3D 11 for presentation ✔
Present a frame for every VSync ✔
CPU queue = 16
GPU queue = 12
LG TV
HDR Filmmaker Mode
Game Optimizer not being used.
Denon
HTPC connected to HDMI 4 (Game 1).
Output via Monitor 1 ARC/eARC.
Things Already Tested
madVR
Presentation options
Queue sizes
HDR settings
Various renderer options
Returned to baseline
No setting consistently fixes the issue.
Windows
Restart
HDR Off
Desktop SDR
Restart reliably restores proper HDR operation.
NVIDIA
Multiple control panel adjustments
RGB vs YCbCr experiments
Color depth verification
Refresh-rate verification
No permanent fix.
HDMI
Verified cables
Tested startup order
TV-first startup improves reliability
Current Working Theory
The evidence suggests the issue is not simply a madVR rendering bug, because:
The TV enters HDR mode correctly.
The Windows HDR desktop is also washed out.
Exiting HDR immediately restores normal SDR colors.
The most likely area is the interaction among:
NVIDIA RTX 5070 driver (Studio Driver 610.62),
Windows HDR output pipeline,
HDMI handshake/EDID negotiation through the Denon X4800H to the LG C4.
madVR appears to expose the issue by requesting the HDR mode switch, but the symptoms affect the entire HDR output rather than just video rendering.
Current Baseline (Do Not Change)
Windows HDR OFF
NVIDIA output: RGB Full, 10-bit
madVR:
Delay playback until renderer queue is full
Direct3D 11 presentation
Present every VSync
CPU queue 16
GPU queue 12
TV-first, then Denon power-on sequence before initiating HDR playback
Denon hdmi 4 at 8k enhanced. HDMI control and arc are off
Lgtv all Cec options disabled , 4k deep color enabled game optimizer disabled on tv and v sync disabled NVIDIA
HTPC stays on as plex server. Wake up order I’ve tried Denon first 30 sec LG 40 sec then HTPC visible and try hdr file.
That didn’t work as regularly so I swapped. Now lg on first 30 seconds then Denon 30 seconds and into windows and hdr file open.
If hdr plays well it’ll wash out if I move the cursor working the playback window and return to full color once I stop.
If it’s washed out from the start I often have to restart HTPC to fix it
Yesterday I did face mode Ddu uni
Installer and then clean installed a new NVIDIA driver 610.62
Ideas for how to proceed from here?
Thanks