https://bugs.kde.org/show_bug.cgi?id=499934
--- Comment #7 from Zamundaaa <xaver.h...@gmail.com> --- (In reply to Confined from comment #3) > Is it possible for an application to ignore the SDR brightness setting while > displaying HDR content? No. It could technically match the reference luminance without altering the content, but that's very heavily discouraged because it has a ton of negative side effects. > I'd like my HDR media to be shown unaltered but find > 203 nits too bright for desktop use, so needing to adjust the SDR brightness > every time an HDR file is played seems a bit tedious. There's no such thing as "unaltered", unless you're in the viewing environment the content was mastered in. I'll elaborate more below. (In reply to Geoffrey Chancel from comment #4) > I have a legitimate question because I am quite ignorant on the subject, but > why is the "original" brightness of HDR content is at 203 nits SDR > brightness? Why specifically this value? 203cd/m² is defined by BT.2408 as the reference white for content using the PQ or HLG transfer functions. In other words, in a HDR10 video, "SDR" things like subtitles are 203cd/m² bright, and the entire video's brightness is relative to 203cd/m². Windows games completely ignore these standards, but you can configure their brightness levels to work fine with this. (In reply to paul-serres from comment #5) > Isn't the point of the SDR brightness setting so that you can make SDR > content looks normal when HDR is enabled? Why link them like this? wouldn't > it have made more sense to add a separate HDR brightness slider instead of > doing this? What would that "HDR" slider apply to? Something that goes 10% above SDR brightness levels? 20%? 50%? Something only with specific transfer functions? If so, which ones? If you re-encode an SDR image with BT.2100 (as you might do with screenshots for example, to handle HDR content on the screen) and you'd have a separate brightness slider for BT.2100 content specifically, then that screenshot would look radically different from the image you just viewed on your screen. Qt applications will soon start using scRGB for rendering with HDR content in their windows, doing such a separate brightness slider would completely wreck the brightness of "SDR" things in their windows too. So no, a separate "HDR" brightness slider is out of the question. The point of the "Maximum SDR Brightness" slider is merely to set what 100% means for the normal brightness slider, because HDR screens are terrible and their self-reported values can't be trusted. It'll be moved into a calibration page sooner than later. (In reply to TheFeelTrain from comment #6) > I want my HDR content to follow the EOTF as closely as possible. Unless you're matching the viewing environment to the one the content was mastered in, that's just plain nonsense. If your room is brighter than the one the content was mastered in, then you need to view the content with increased brightness, or it will look darker than it's supposed to. If your room is darker than the one the content was mastered in, then the content needs to be presented with decreased brightness, or it'll look brighter than it's supposed to. (In reply to TheFeelTrain from comment #6) > At the very least rename the current slider to something else. The setting > shouldn't have "SDR" in the name if it's a slider for HDR. Suggestions would be welcome. It's called the "Maximum SDR Brightness" to have some attachment of what it controls. Calling it "Maximum Reference Luminance" would be more technically correct, but most people seeing it wouldn't understand what it means. -- You are receiving this mail because: You are watching all bug changes.
