Custom Resolution Utility (CRU)

[ps24u]

Hey ToastyX, all,
I've been pulling my hairs for the past couple of days, almost a week now, trying to have the nVidia driver output RGB limited (16-235).
Yes it's the exact inverse problem 99% of the posts on the internet have, where everyone wanted RGB full range (0-255) when using HDMI outputs to their device.

I really could use some help at this point..

Here's the data:
- on Win7 SP1 32bit
- using nVdia driver 342.01 WHQL because it's the last supported by my GPU (Geforce 8 Series 8500GT).
- My main (and only) display is an old (2010) Sony HDTV 40W4500. It doesn't support RGB full range via any HDMI inputs.

The issue:
Although I'm connecting the 8500GT directly to 40W4500 via HDMI (with spdif passthough taken from my mobo to an input on the GPU), I'm always getting RGB full out of the nVidia driver, either from the generic Win7 MS one to the latest nVidia one for my card.
The result is black crush on the desktop and everything except videos (for which madVR does the trick, thank god, to output the correct range).
I tried at least 20 nvidia drivers, from the early 190.x, 250.x up to 342.01 with no difference whatsoever, they're always outputting RGB full.
It's completely nuts as the whole of mankind has been having the exact opposite problem for 8-9 years, and here I just wished it happened to me once xD

Here are my findings:
- nVidia driver 347.09 and newer have a simple (fucking) toggle to select either RGB full or RGB limited, my dream on earth atm. Sadly it doesn't support my GPU. Modding the inf went nowhere (it installed but doesn't recognized the GPU, driver won't start when associated with this GPU as reported in Win7 dev manager).
- On the exact same system, same card, same driver version (342.01 for XP), same HDMI cable, same TV, but using Windows XP, I *do* get RGB limited by default, no questions asked, without any tweaking whatsoever.
I'm absolutely baffled. It seems to me that the nvidia driver on Win7 just won't output RGB limited under any circumstance all. But then why all these posts on the web trying "to force RGB full"...?
- I know I can use YCbCr444 from the nVidia driver for the "Digital color format" to get proper levels but colors are a bit off compared to RGB limited on my device.
- I tried the "Nvidia RGB Full/limited range toggler" (adds SetDefaultFullRGBRangeOnHDMI to registry, of course setting it to "0" to try to force RGB limited, no go).
- I tried changing registry values in the nvidia registry entries trying to force the display to be detected as an HDTV, which IT ALREADY IS IN THE NVIDIA CONTROL PANEL, no go.
I absolutely don't get why the driver doesn't want to output RGB limited when it's clearly detecting an HDMI connection going to an HDTV.
- I started reading CTA-861-G_FINAL_revised_2017 trying to find what to change in the EDID to try to force RGB limited this way but it's sooooo complex it didn't help at all ^^;

Now, I have 2 more leads.
- The first one is possibly the nVidia driver not considering my HDTV really as such because the audio is passthrough and no "nvidia HD Audio driver" is installed on the system.. Before GPUs started to have onboard HDaudio, a couple models including mine had this spdiff plug on the GPU to use as passthrough.
If that's the case, because the driver truly doesn't consider it as an HDTV, it sends RGB full (even though, again, the control panel sees the monitor as an HDTV and the connector is indicated as HDMI - HDTV).
- The second: the EDID from my HDTV is old/incomplete and under Win7 the nVidia driver sees it as supporting only RGB full and so enforces that??
(which would be strange because the same driver version on XP uses RGB limited, then again the XP driver could be hardcoded to send RGB limited regardless of EDID?)

So, is there a way I can modify my HDTV's EDID to specify it (only) expects RGB limited?
Here is the dump of my oridinal EDID:

  40W4500.bin (Size: 256 bytes / Downloads: 404)


Sorry for the very long post but I needed to put everything down.
If someone can give a hand, by all means..

ps24u