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[stricko]

Hi there, I'm battling through the delights of setting up 4k and HDR. Setup is a nvidia GT1030 gpu, output via HDMI to a Denon AVR-X1400 and then onto a Optoma UHD51 projector. Windows 10 64 bit, all updates and drivers up to date.

By a mix of trial and error and titbits picked up from various threads, I've made some progress. I've done nothing to either the Windows Display Settings, or the nvidia driver settings other than to set the resolution to 4k, and scaling to 200%. Within MC24 I have Video Mode: Advanced – Custom, with Custom Video Mode starting with Red October HQ, but no rules set. MadVR settings are default apart from HDR passthrough being set for the projector. Hardware accelerate video is checked, and Display Mode Automatic Change Mode is On.

After all this, the projector is recognizing when I'm sending it a HDR source (typically MKVs), but the resulting image then has a vivid green cast. I've tried changing cables, power up sequences etc, but nothing seems to help.

Projector is happily recognising HDR, and displaying it correctly from other sources. I'm well out of my depth here, so any help or suggestions would be much appreciated.

[tij]

any particular reason why you use Custom ... and not just ROHQ?

[stricko]

Good question  There is another thread which talks about GPU performance issues for HDR. I also have the same problem with some big MKVs (50gb+) and was prepping to try the approach discussed there. I was assuming (I said I was out of my depth...) that Custom, starting with ROHQ, with no rules set is effectively just ROHQ.

[tij]

does SDR have this green cast ... or only hdr stuff?

[stricko]

SDR is fine, in fact better than fine, it's excellent. For SD, HD and non-HDR 4k material it looks great.

[tij]

can you post screenshot of this green stuff ... with MadVR OSD overlaid on top (press Ctrl+J) to get OSD to show while playing file

[stricko]

prtscn attached. picture isnt green, although it appears green on the projector..... ive swapped cables, ports on the projector but no luck

[tij]

does your projector goes into hdr mode?

[tij]

that screen shot looks a bit washed to me like hdr is not pass throgh

... if your projector does not go to hdr mode ... that means your receiver is doing something wrong ... see link below on what to do with denon in that case

https://denon-uk.custhelp.com/app/answers/detail/a_id/4377/~/hdr-passthrough-not-working

[stricko]

Good tips guys. But no luck so far.

Just to restate something from earlier post, projector and AVR are showing 4k HDR content from Amazon Fire Stick without problems. Info on projector shows full 4k resolution and HDR enabled.

So I've upgraded the firmware on the AVR and enabled HDR passthough and 4k Enhanced Signal Format as per the Denon document in the link. I've moved the HDMI input for the HTPC as close to the HDMI output port as I can.

When showing HDR content from the HTPC, the projector shows that HDR mode is enabled. But still the same green cast.

I've checked out the HDMI cables as best I can. The long (10m) lead from the AVR to the projector is supposedly certified 2.0b, 18gbps. Not so sure of the provenance of the lead from the HTPC to the AVR, so I've ordered up a new one, again certified 2.0b. One obvious step would of course be to bypass the AVR, and use the projector lead (which we know is handling 4k HDR correctly from the Fire Stick), but the design of the low profile GPU card means that I can't get the cable into the socket, even with the case off.....

All ideas gratefully received......
 

[tij]

From screenshot it looks like you using D3D9 … in madVR settings [Rendering] -> [General Setting] try enabling [use Derect3D11 …] and also [present a frame for every VSync]

Window version and NVidia driver version you have installed will be useful info too (type winver to get first one … second one is NV Geforce Experience)

Also, in MadVR settings [devices], did you set profile of your Projector (ie identify device as Digital Projector etc?)

PS. if HDMI cable is bad it usually shows "sparkles" (random white dots appearing on screen) or goes completely blanc

[stricko]

Windows 10 64 bit version 1803 build 17134.285
GeForce gt1030 4gb driver 399.24

I made the made changes you suggested. No change, still green. Projector was already identified as such.

Thanks for the help with this

[tij]

what is MadVR version (at bottom left of MadVR option screen)

[tij]

I don't have projector set up … just plain LG OLED atm … blew all my money on 36 drive NAS

but doing quick google search on your projector … looks like out of the box, the brightest mode of your pj may have green tint to picture (uncalibrated … PJ will have color shifts especially in brightest mode)

https://www.avsforum.com/forum/68-digital-projectors-under-3-000-usd-msrp/2955818-optoma-uhd51a-4k-hdr-3d-dlp-projector-w-alexa-40.html

https://www.tvspecialists.com/optoma-uhd65-vs-uhd60/

so i think its not your PC or your AVR or HDMI cable ... but projector that is adding green tint when it goes HDR (likely going to brightest mode)

so things i would try is (1) try another mode in your PJ for HDR with less brightness just to see if green tint go away (probably loose brightness) ... (2) use latest firmware on PJ ... (3) get your projector calibrated (madVR supports 3Dlut ... so calibration can yield outstanding results)

PS: if you use RO Standard ... do you get green tint on HDR content?

[stricko]

Thanks for all this, I'm open to all ideas for how to get to the bottom of the problem.

I may have understated just how green we are talking about here. This isn't a tint, as described in the AVSForum thread. This is essentially a green screen. No other colour is present. But I followed the logic of your suggestion and tried every possible brightness adjustment, mode, gamma setting etc etc that I could find. I just got a very broad range of greens.

But I keep coming back to the PJ behaving perfectly when it gets a 4k HDR signal from the Fire Stick. No hue, no tint, just natural vibrant colours. The Fire Stick says it is sending HDR and the PJ says it's receiving HDR. And it's all over the same cable, and into the same port on the projector as it is for the HTPC.

The PJ came back from Optoma 2 days ago after a firmware update..... same result before and after.

I tried switching into RO Standard, both directly, and as the starting point for custom. No HDR flag, picture is a normal colour range, but very muted, as you'd expect.

I'm a member of the AVS forum, and I already have a thread open about the problem on the UK equivalent. I'll copy it over to the US version to see if I get any ideas.

I really do appreciate your input on this. I hope it turns out to be something really stupid and obvious that I can be embarrassed about ;-)

HOLD ON, HOLD ON

Eventually found something on the US thread, somebody else with exactly the same problem. Key to it seems to be a possible bug in the PJ firmware, but more importantly changing the colour space on the nvidia driver page. Changed from RGB to YUV and bingo, HDR with natural colour!!!!!!!!!!!! From what I'm reading, and the limited results I've had so far, there is still a bit of work to do to tune things, but, I'm over what was looking like a pretty insurmountable problem. Thanks again for your help