Heyoo, I tried searching for info on this particular issue but didn't really find the exact problem being discussed:
I have an LG B7 hooked up to my computer, it's actually my primary monitor in between my two smaller IPS monitors, used for pretty much everything I do. The relevant specs on my PC otherwise are i7-2600K @ 4.5 GHz, 1080 Ti, 16 GB DDR3 and Win10 Pro.
For the longest time I had issues finding a good way to play back HDR material, the TV's apps got great quality but lacked compatibility with video formats and subtitles, using an external drive to transfer to the TV is a hassle, streaming via Plex or DLNA proved problematic as well (Plex server can't transmit data fast enough, while LG SmartShare just turns itself off around every 10 minutes or so...), VLC stutters like mad and has artifacts in bright white areas, and I had trouble getting HDR to work in Windows too in general.
Now I'm realllyy close to a working solution, I think. I'm running MPC-BE x64 with latest madVR, and I'm getting very nice quality out of it. HOWEVER there are still a couple of hitches. Main one: It doesn't seem like madVR is actually properly capable of passing the metadata through, for whatever reason, on my current setup. Let me explain how the current behavior currently looks like:
-If I don't turn HDR on in Windows, launching an HDR film in MPC-BE triggers the HDR state change in the TV and I get "HDR". Biggest problem with this is that it kind of flickers on and off, it's not stuck on consistently, and worst is that after I shut down MPC-BE my three monitors go out of alignment, and I have to re-align them in the display settings.
-If I DO turn on HDR in Windows and launch an HDR film in MPC-BE, it looks the same as in the above case, so "HDR", and additionally it's both steady and doesn't have the issue with shutting the program down causing display alignment issues.
-However if I use the "SDR content brightness" slider in the Display Settings sub-menu for HDR and UWCG, it changes the brightness of the video played by MPC-BE. This means it's not actually running in HDR?
-Further I noticed that in the madVR HDR settings for the TV it's set to allow madVR to decide what to do. I went through the settings by hand, and it turns out that the setting that matches madVR's automatic selection is the "convert HDR -> SDR" option. So even though it triggers HDR to turn on with the TV, it's not ACTUALLY doing proper HDR.
-And finally if I manually set it to passthrough the metadata to the TV, the image goes horribly, awfully washed out, definitely nothing like HDR there.
Any ideas on what might be happening, or possible troubleshooting steps I could take? Getting MPC-BE to trigger the HDR state change is very very promising, but based on the behavior of the madVR settings it's clear that I'm still not getting true HDR, processed properly by the TV. The same video files, if I put them on an external drive and run with the TV's own video app work great, meaning there should be proper data in there. If it wasn't for the damn subtitle and occasional format conflicts with the TV's app I'd just go ahead and go through the hassle of using an external hard drive, but it feels like I'm so damn close to cracking it with madVR I don't want to back off yet.