madVR Options Explained

[Qaq]

Well, for IGPUs/APUs it may be a totally different story of course. Different architectures, different traffic routing. I use myself CBd with madVR on G1830 just fine for almost any video now.
Let alone GPU-Z for AMD without screenshots. GPU-Z doesn't show much for my 7750 anyway. With AMD we have to "copyback" OpenCL data and here comes PCIe bottleneck. Lets route there DXVA CB traffic as well?

[huhn]

Originally Posted by Qaq

Well, for IGPUs/APUs it may be a totally different story of course. Different architectures, different traffic routing. I use myself CBd with madVR on G1830 just fine for almost any video now.
Let alone GPU-Z for AMD without screenshots. GPU-Z doesn't show much for my 7750 anyway. With AMD we have to "copyback" OpenCL data and here comes PCIe bottleneck. Lets route there DXVA CB traffic as well?

the openCL copyback issue use the same bandwidth yes. but do you notice a difference in speed there?

AMD d3d <-> openCL intreop looks like a terrible inefficient copyback while DXVA CP/D is very efficient.

[Telion]

Do AMD APUs suffer from this d3d <-> openCL copyback issue? Isn't hUMA supposed to overcome exactly this kind of problems? Should madVR explicitly implement some kind of hUMA support, or it is a driver's task? If it's the former, would madVR implement it some day?

[huhn]

madVR uses openCL cl_khr_dx9_media_sharing and it looks like it is designed to copyback.

AMD APU usually have a to weak iGPU anyway so the buttleneck is not the bandwidth and in the end they don't use PCIe for copyback in the first place

[Soul]

hi.. what is the best option for GPU queue size and CPU queue size? I have GTX750 NVidia.

Thanks

[huhn]

default is usually optimal.

Is there truly no benefit to using Chroma Upscaling and/or Image Doubling/Quadrupling on TV's that are set to use 0-255 range, RGB, but limited to 4:2:2. In my case, 4:4:4 simply looks really bad (too dim) on my TV, leaving 4:2:2 as the only real choice.

[Asmodian]

The high cost Chroma Upscaling and Chroma Image Doubling options will not provide as much benefit (and their benefit is already minor) when using 4:2:2 but they do still provide a benefit. Luma Image Doubling is still very helpful.

However, I have never seen a TV that changes brightness or contrast due to 4:4:4 or 4:2:2, are you sure you are not confusing limited range (16-235) with color sub-sampling? Usually 4:4:4 or 4:2:2 is not something you can easily change unless your TV has a PC Mode. Also the difference is somewhat subtle, hence the need for an image to test for 4:2:2 or 4:4:4.

[vivan]

Originally Posted by Asmodian

However, I have never seen a TV that changes brightness or contrast due to 4:4:4 or 4:2:2, are you sure you are not confusing limited range (16-235) with color sub-sampling? Usually 4:4:4 or 4:2:2 is not something you can easily change unless your TV has a PC Mode. Also the difference is somewhat subtle, hence the need for an image to test for 4:2:2 or 4:4:4.

No, he is just used to LSD colors of his Samsung and that extreme postprocessing is disabled in PC mode or something.

[pirlouy]

I have a 2009 Samsung TV and indeed, when using PC mode, you lose all post-processing, and image looks insipid.
In fact, image is surely normal, but when you compare to Samsung post-processing, it looks insipid.
My solution has been to increase saturation in madVR, and I manage to have the same result.
I don't know if I should blame Samsung for that, but I prefer a saturated image now. xD

Originally Posted by vivan

No, he is just used to LSD colors of his Samsung and that extreme postprocessing is disabled in PC mode or something.

Might want to think before you post or at least ask. ALL post-processing is completely turned off and I calibrated each mode using both manual settings and 3DLUT with i1Display Pro. I could calibrate 4:2:2 mode color gamut, but not 4:4:4 PC mode because color gamut calibration does not apply to PC mode. This, however, should make no difference since I applied 3DLUT on top of each calibration and the results were very accurate.

I use Standard mode (with all post-processing disabled in User Menu and in Service Menu) + Game mode (4:2:2), which reduces input lag by further bypassing post-processing. It looks identical to fully calibrated Movie mode, but Standard + Game mode simply provides better/lower input lag.

4:4:4 PC mode looks bland, pale and kind of dim, even with 3DLUT. Its not just me - other Samsung VA owners reported similar findings. I also own Samsung PNF5350 Plasma TV and PC mode (4:4:4) looks perfectly fine, better than 4:2:2 modes. It seems like the problem is with specific Samsung VA screens.

[Asmodian]

Obviously all post-processing is not off if it looks very different? All post-processing you can turn off is off. It sounds like Samsung has a correction/calibration tied to a post-processing chip that operates in 4:2:2 and changes the way the panel runs outside the 0-255 RGB input values (if a 3DLUT cannot fix it).

Have you tried creating a 3DLUT with a saturation intent when in PC mode?

Originally Posted by Asmodian

Obviously all post-processing is not off if it looks very different? All post-processing you can turn off is off. It sounds like Samsung has a correction/calibration tied to a post-processing chip that operates in 4:2:2 and changes the way the panel runs outside the 0-255 RGB input values (if a 3DLUT cannot fix it).

Have you tried creating a 3DLUT with a saturation intent when in PC mode?

What do you mean 3DLUT cannot fix it? In both 4:2:2 mode and 4:4:4 mode 3DLUT accuracy is just as high. Everything is within dE 1 with proper Rec.709 gamut (not wide gamut or anything). I even had it re-checked with i1Pro. Post-processing in Movie mode 4:2:2 is completely turned off by default, but it looks the same as Standard mode, which requires manual turning off of all post-processing. I am saying that all 4:2:2 modes look better than 4:4:4 mode, which to me looks dimmer and duller. I wonder if the difference is in luminance. Colors depends on saturation, hue, and luminance. There are controls for saturation and hue, but not luminance. I mean I even visited the hidden Service Menu and made asbsolutely sure no post-processing was used. Again, Game mode by itself further removes post-processing. When I switch to PC 4:4:4 mode, the same post-processing options are grayed out as the ones I manually turned off.

Let's say I calibrate 4:2:2 color gamut to read exactly as 4:4:4 color gamut for some specific color (fullscreen pattern). Then I can toggle between 4:4:4 PC mode and 4:2:2 non-PC mode (be it Standard or Movie). i1Display Pro and i1Pro will read it as the same color in both modes within the same dE, but 4:2:2 will look brighter/more vivid/vibrant (luminance)? Yet, if it was some post-processing affecting the color, then i1Display Pro or i1Pro would pick it up, wouldn't they? More vibrant or vivid or brighter color than the other color = different dE reading, but such is not the case. It also baffles me! I mean what kind of post-processing could this be?

Maybe it is possible that contrast ratio plays a role because the max I can squeeze out of 4:2:2 modes is 2600:1 and out of 4:4:4 only about 2200:1. Don't worry - all dynamic contrast and such junk is turned off in all modes, but contrast ratio's differ by about 400:1. However, would such a small difference in contrast ratio have any effect on a fullscreen color pattern looking different? The reason why PC mode has lower contrast ratio is because it is impossible for me to max out white balance gains due to locked controls. I am quite certain if I could max out white balance gains in PC mode, then I could get identical contrast ratio.

Bah, it could be simply because PC 4:$:4 mode is set at 90cd/m^2 and 4:2:2 modes are set at 110cd/m^2 using identical brightness and backlight settings.

[huhn]

by calibration you should first set white 255 to 100-120 cm² before 3d lut calibration.

a colorimeter is reading the all over color not from some pixel so post processing can still be used.

[Asmodian]

Originally Posted by XMonarchY

I wonder if the difference is in luminance. Colors depends on saturation, hue, and luminance. There are controls for saturation and hue, but not luminance. I mean I even visited the hidden Service Menu and made asbsolutely sure no post-processing was used.

Bah, it could be simply because PC 4:$:4 mode is set at 90cd/m^2 and 4:2:2 modes are set at 110cd/m^2 using identical brightness and backlight settings.

luminance = brightness. It looks like you found your answer.

Originally Posted by huhn

by calibration you should first set white 255 to 100-120 cm² before 3d lut calibration.

a colorimeter is reading the all over color not from some pixel so post processing can still be used.

So what kind of processing can affect the way pixels look or how vibrant or bright they look without affecting the actual color properties? I just can't imagine something like that.

[huhn]

first check if both modes have a white point of d65 at 120 cm².

Originally Posted by huhn

first check if both modes have a white point of d65 at 120 cm².

They do (all 3) have D65 white point, but cd/m^2 for each mode differs slightly. Movie mode is darker than Standard mode with identical values for brightness, contrast, and backlight. PC mode is dimmer than Standard mode, but brighter than Movie mode using those same identical settings and appropriate 1DLUT (each mode needs its own 1DLUT for games and 3DLUT for films). Again, this happens due to lack of RGB White Balance controls in PC mode.

ANYWAY, it doesn't really matter because all I wanted to know is whether there is still some benefit from upscaling chroma for 4:2:0 content to 4:2:2 mode and the answer is YES, but it is mild.

[huhn]

numbers please...

OK, I verified - white point cd/m^2 are the same just like contrast ratio.

Here's a thought - can a slight bit of sharpness affect colors, as in full-screen single-color patterns? I disabled sharpness everywhere in User Menu, but also dug deep into Service Menu and loosened sharpness there, Edge Enhancement was also disabled. There is a SLIGHT big of sharpness compared to Movie or PC mode, but it is there. Can sharpness somehow affect pixel vibrance or color? I am talking about PURE single-color fullscreen patterns here, not some complex-color image.