madshi bug tracker - madVR
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0000638madVRbugpublic2020-02-19 12:432020-02-21 15:51
zeus0r 
 
normalminoralways
newopen 
PCWin 10latest
v0.92.17
MPC-HC
1.7.13 (64-bit)
 LAV Filters 0.74.1
DXVA2 Copyback
none (progressive)
no
Off
fullscreen exclusive mode
NVidia
Geforce GTX 980
442.19 - WHQL (latest)
0000638: wrong black levels SDR/HDR
i'm not 100% sure but i think it started with the latest nvidia driver update. i've been using this setup for quite some time without any problems but i recently noticed wrong black levels for HDR content while SDR content is fine. (madvr hdr passthrough enabled)

rgb full range (0-255) is enabled in madvr settings and it currently gives me correct black levels for SDR content but i need to change it to 16-235 in order to get correct black levels for HDR content. (otherwise blacks are grey)

i checked this with some black level test files where 0-16 should be black and 17-25 flash.

0-255: correct SDR black levels but greyish blacks for HDR content
16-235: correct HDR black levels but bad black crush for SDR content

could this be a nvidia bug? or is there someting i am missing here? would it be possible to add another black level setting for HDR content so i don't need to switch?
No tags attached.
Issue History
2020-02-19 12:43zeus0rNew Issue
2020-02-20 17:10madshiNote Added: 0002667
2020-02-21 11:22zeus0rNote Added: 0002673
2020-02-21 13:09madshiNote Added: 0002674
2020-02-21 13:40zeus0rNote Added: 0002675
2020-02-21 15:51huhnNote Added: 0002676

Notes
(0002667)
madshi   
2020-02-20 17:10   
Have you forced the Nvidia GPU to RGB Full Range output? That's the recommended configuration.
(0002673)
zeus0r   
2020-02-21 11:22   
okay, now i'm even more confused.

i'm pretty sure i actually chose "RGB/full range/12 bit" in nvidia settings but when i just checked "YCbCr/limited/8 bit" was active. and even weirder: i can't change it to RGB, it's just not there.

so i changed the resolution to 1080p/60 (2160p/60 before) and then i can pick RGB/full/12bit. so i checked black levels again but the problem was still there:

0-255: correct SDR black levels but greyish blacks for HDR content
16-235: correct HDR black levels but bad black crush for SDR content

then i tried pretty much every combination possible and with RGB/limited/12bit: correct black levels for SDR and HDR.

wtf?! why can't i choose RGB with 2160p anymore? and why is limited the correct choice now when it was full range before?!
(0002674)
madshi   
2020-02-21 13:09   
Not being able to choose RGB for 2160p60 means that whatever device your HTPC is connected to (display or AVR or whatever) seems to report that this device's HDMI port doesn't have enough bandwidth for 2160p60 RGB. The HDMI input port of the display/AVR needs to be 18Gbps for that to work. Seemingly it's only being reported as 10Gbps instead.

I don't know why RGB Full doesn't work for you. It works for most other users, including myself. Not sure how to fix it. It's probably some sort of Nvidia driver issue. Try reinstalling the Nvidia drivers in "cleanup" mode, maybe?
(0002675)
zeus0r   
2020-02-21 13:40   
okay, interesting. i'll try that, thank you!
(0002676)
huhn   
2020-02-21 15:51   
there are more than one report of user needing or getting different level between HDR and SDR in the past days.

if listed they where Phillips Tvs.