SUMMARY While playing HDR videos with MPV, the brightness is all wrong and highlights are blown out, when using a very low SDR brightness setting in System Settings/Display & Monitor STEPS TO REPRODUCE 1. Use "ENABLE_HDR_WSI=1 mpv --vo=gpu-next --target-colorspace-hint --gpu-api=vulkan --gpu-context=waylandvk" to play an HDR video on an HDR capable monitor 2. Turn the SDR Brightness slider in Display Configuration up and down 3. Watch the hilights blow out and the video look terrible Operating System: Fedora Linux 40 KDE Plasma Version: 5.90.0 KDE Frameworks Version: 5.246.0 Qt Version: 6.6.1 Kernel Version: 6.6.6-200.fc39.x86_64 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5800X 8-Core Processor Memory: 31.3 GiB of RAM Graphics Processor: AMD Radeon RX 6700 XT Manufacturer: Gigabyte Technology Co., Ltd. Product Name: X570 AORUS ELITE System Version: -CF
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/4828
Git commit 4425bcd4e0b98a91c3500afe7204fec22b9032f6 by Xaver Hugl. Committed on 22/12/2023 at 13:28. Pushed by zamundaaa into branch 'master'. backends/drm: handle missing brightness values in the EDID better Most importantly, fall back to an assumption of 1000 nits peak brightness when the max brightness is missing, instead of the sdr brightness, which causes more immediately visible issues. Ideally the user should configure this value in the display settings, but it's too late to still do that for Plasma 6.0. M +5 -8 src/backends/drm/drm_output.cpp M +10 -16 src/backends/drm/drm_pipeline.cpp M +4 -4 src/core/output.cpp M +7 -7 src/core/output.h M +24 -5 src/utils/edid.cpp M +13 -10 src/utils/edid.h M +3 -3 src/wayland/outputdevice_v2.cpp https://invent.kde.org/plasma/kwin/-/commit/4425bcd4e0b98a91c3500afe7204fec22b9032f6
(In reply to Zamundaaa from comment #2) > Git commit 4425bcd4e0b98a91c3500afe7204fec22b9032f6 by Xaver Hugl. > Committed on 22/12/2023 at 13:28. > Pushed by zamundaaa into branch 'master'. > > backends/drm: handle missing brightness values in the EDID better > > Most importantly, fall back to an assumption of 1000 nits peak brightness > when the > max brightness is missing, instead of the sdr brightness, which causes more > immediately > visible issues. > Ideally the user should configure this value in the display settings, but > it's too > late to still do that for Plasma 6.0. > > M +5 -8 src/backends/drm/drm_output.cpp > M +10 -16 src/backends/drm/drm_pipeline.cpp > M +4 -4 src/core/output.cpp > M +7 -7 src/core/output.h > M +24 -5 src/utils/edid.cpp > M +13 -10 src/utils/edid.h > M +3 -3 src/wayland/outputdevice_v2.cpp > > https://invent.kde.org/plasma/kwin/-/commit/ > 4425bcd4e0b98a91c3500afe7204fec22b9032f6 Is this functionally equivalent to running "kscreen-doctor output.2.maxBrightnessOverride.1000" ?
Managed to recompile Fedora's kwin with this patch, and can confirm it does fix the issue. Thanks!