Custom Resolution Utility (CRU)

[Jonotallica]

Hi,

I'm new here, and have been trying to fix something for a few months, had a break and focused on a few other things, but am back on this stuff again, and would really like to try and sort it out asap. So I dived deep into CRU in the last day or two and frustratingly got half way to thinking I'd done it.. but had no luck so am looking for some advice, from anyone who may be able to help.

I'll try to type it out as simple as possible.. hopefully this isn't too much of a complicated one. Apologies if it's long. I'm trying to juggle two seperate issues and fix them one way or the other.

I have a Samsung 27 inch monitor.. S27C750 with native refresh rates of 50, 59 and 60hz @ 1920x1080 through HMDI connection.. into an NVIDIA GTX 780 Ti. My main concern is video playback in terms of lots of different video types and formats and lots of different frame rates.. 23.976, 25, 29.970, 30, 50, 59.994 etc. I've been doing a lot of video editting in the last few months and would prefer to have the refresh rate of the monitor locked into multiples of these frame rates for smoothest playback and syncing of frames. I've pretty much done that ok with most video types, except for the Blu Ray files that are 23.976.

My temporary solution of using a custom refresh rate/resolution of 48hz in NVIDIA Control Panel half worked.. but introduced a new problem, which I've had problems fixing all year, and still haven't found a solution. I tried editting the EDID of the monitor itself, making a custom monitor inf file, and even the simpler solution of building a custom resolution within NVIDIA Control Panel and so far haven't had any luck, and so far haven't been able to sync up those 23.976 videos properly.

The monitor doesn't support 48hz natively, but when using it in NVIDIA Control Panel as a custom resolution it works flawlessy, except for one frustrating problem. The RGB range is set to limited, and even if I change it to 'full' 0-255 within the drivers, it says that it has changed it onscreen but onscreen nothing changes.. and the colours stay washed out and pale and look really bad. Not just in videos but in the desktop, browser, etc.

Initially I assumed it was a monitor hardware problem in that it could support that resolution (unofficially) but that because it's outside of it's stated frequency range it would create this colour problem, but upon further testing in the last few days, it's become clear that it's actually an NVIDIA driver issue.

Because.. when I create other custom resolutions that use a refresh rate within the official range of 50-60hz.. the same issue occurs. So 54hz, or 58hz creates the same washed out colours problem. I live in PAL territory so my default refresh rate in windows is 50hz for HDTV content or 25fps PAL DVD's, and then my video player temporarily changes the refresh to 60hz when watching YT videos or NTSC content of 30fps. Everything works well except for film which is 23.976 introducing the 'judder' during panned shots, and my aim so for proper syncing for all video content that I encounter.

To conclude on that.. the only way I'm able to get full range 0-255 colour with my NVIDIA card and drivers (which looks great, both in windows and in video playback) is to use the 'native' resolutions with refresh rates of 50, 59 or 60.

So my mission has been to get NVIDIA drivers to recognise 48hz as a native resolution. I got sooo close.. but frustratingly fell short with CRU at the final step. I'd be appreciative of any help you can offer in terms of overcoming this final step.

I took some hours to experiment and familiarise myself with the CRU program and it's options. I was able to nail down the options I am looking for in the 'Extension Blocks' section of CRU, in the CEA-861 section.. and in the 'TV resolutions' section.. by playing around with those, I was able to create my own NVIDIA 'native resolutions', or remove them, for example having it so that NVIDIA would only show 60hz as the only native resolution, or 50hz etc. So that was some progress.



Everything else I tried either yielded no results at all, or undesirable results. For example, in the VTB-EXT and DisplayID sections, the changes did go through but it changed the recognition of those resolutions to DVI.. despite using HDMI cable.. and ALL resolutions became washed out and pale.. and I lost full range colour for all of them. Showing once again, that my 48hz pale colour problem, is a NVIDIA driver issue, not a hardware issue.. as I now had this same colour for every resolution on the list, even the native ones.

So far the only way I've been able to maintain the full range colour that I desire is to use HDMI 'TV Resolutions' that are recognised as 'native' by the NVIDIA drivers. Everything else messes the colour up.

The frustrating part is that 48hz is the only change within all the resolution options that doesn't work. The tick box for native resolution is greyed out, despite being ok with my monitor (unofficially), where as 24 or 25, or 100hz is able to be ticked. And I even switched to this mode (25hz) without my monitor supporting it and then had the monitor go black and say that it isn't supported. And have to revert back. The tick box is available to tick for all of the others, and NVIDIA Control Panel will recognise these extra modes which is exactly what I've been looking for.. EXCEPT the one mode that I really want.. 48hz is unavailable as a native resolution.



As you can see the 25hz option is bolded, and even though I haven't done so in the screenshot, I could do the same for 24, 100, or 120hz.. but for some reason not 48hz, even though this is the mode that my monitor would actually be able to handle. I have no way of 100% confirming it, but I am hoping that by having this option available in the NVIDIA Control Panel in the native resolution section, under HDMI.. that it would give me the full range colour that I've been looking for. In the same way that it does for 50, 59 or 60hz.



The 25hz option has been shown here to do exactly what I was hoping for.. from within the NVIDIA Control Panel.. and windows did try to change to this refresh rate, it's just that my monitor can't handle that refresh rate, so I can't confirm the colour side of things, one way or the other.

If you have any ideas that could help rectify this, or if you know the reason for why this could be happening, I'd be really appreciative as it's been a case of being so close, yet so far.. and a big frustration.

The other way of trying fix this, could be coming at it from another angle.. in terms of trying to get NVIDIA driver to recognise all custom resolutions.. in terms of getting them to show full range colour, because I don't understand why this is happening and that is a problem in itself. There is a full or limited colour option, when creating custom resolutions, I am selecting full colour, and it's still showing as limited. Regardless of whether it's 48hz, or 58hz.

For now, the simplest way seems like it'd be with CRU.. and then saving a bin file, and loading it up whenever I reinstall windows, or reinstalling NVIDIA drivers etc.

If you have any idea of what I could do, I'd really appreciate it, whether it the EDID file, or editting some NVIDIA driver files, or something else.

Thanks