Server Version#: 1.32.8.7639
Player Version#: 1.84.1.4069-ff740b6d
Relevant Server Specs: Windows 11 Pro / 64GB RAM / NVIDIA GeForce RTX 3060 Ti
We have a chunk of 4K HDR HEVC movies, and sometimes we end up watching those movies on a standard HDTV if we’re just sitting the kids down in the living room as opposed to an actual rec room movie night. Our Living Room TV runs off a Roku Stick far enough away from the router that the speed is a bit degraded, so we have the Home streaming quality set to 20 Mbps, 1080p HD (High) to prevent buffering and stuttering. When we do this though, something odd I’ve noticed is that there appears to be some scaling problems with the resulting video, only if HDR to SDR Tone Mapping is enabled.
When watching a 4K HDR Movie converted to 1080p SDR, it ends up with a weird grainy look. A workaround is to create an optimized version targeting original quality, which converts it from 4K HDR to 4K SDR. The resulting optimized version plays back and downscales just fine. If HDR to SDR Tone Mapping is disabled, this issue isn’t present whatsoever, but then the colors are obviously washed out.
I’m attaching a couple of screenshots from the Super Mario Bros Movie credits, where some of the text makes it easy to see what I’m talking about: (You’ll probably have to go fullscreen with the screenshots to tell the difference)
4K HDR → 1080p SDR (Just choosing the movie and selecting play)
4K HDR → 4K SDR Optimized Version → 1080p (Creating an optimized version using the original quality preset, and then playing that)
Hopefully I’ve explained the issue well, but let me know if there’s more details I can provide. Plex appears to scale SDR content perfectly fine, it’s only when HDR to SDR Tone Mapping is enabled when problems start.
