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28th August 2017, 15:16 | #341 | Link | |
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It's cleary visible that it totally disppears. |
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28th August 2017, 17:54 | #342 | Link | |
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Thanks for the update.
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28th August 2017, 19:22 | #343 | Link | ||
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using DXVA native and no DXVa chroma is a whole different story. Quote:
if you want to see banding from DXVA image scaling take the BW.avi output it as 4:2:0 and see for yourself. but the most important part i'm not even sure if DXVA scaling is any faster than lanczos 3 the way madVR is handling it. |
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28th August 2017, 19:36 | #345 | Link |
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"you should see 1024 vertical bar if your display supports 10 bit"
so there are not 1024 steps of banding in there (i can see them on my TV and they say they are there but...) but that's not banding because what again? and if you really think 1024 steps dither to 8 bit is enough to hide them well go ahead and set madVR to a 10 bit internal processing. |
28th August 2017, 19:53 | #346 | Link | |
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You said that DXVA scaling would show banding, so where do you see it? The 1024 step video is totally enough to make EVR or Win 10 video app show banding, which is not there with madVR + DXVA. |
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28th August 2017, 20:18 | #347 | Link |
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there is clear 1024 steps of banding on this file. i can see the banding on your screenshoots. 16 bit dither to 8 bit is clearly better than 16 bit rounded to 10 bit.
the bw.avi is a file that allows you to see the used scaler. EVR normal does a better job than madVR with DXVA scaling so that's important at least on my system: https://abload.de/img/bw04une.png and it is bilinear right now (385.41) which is odd. here you go: http://filehorst.de/d/cmdBtJyd but not sure why you want it because it is not a real video. |
28th August 2017, 21:16 | #348 | Link |
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Can you tell me where do you spot banding here (deband off)?
Software decoding + bilinear: DXVA2 native + DXVA2 scaling: The only difference I see is that bilinear is softer here, so the grain in the gradients is harder with dxva2. But I don't notice additional banding. -> Still not noticing any "real world" problem. |
29th August 2017, 11:50 | #349 | Link |
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there is no real banding in this example.
but you are downscaling a 10 bit source it's harder to add banding there. nvidia 384.41: bicubic: https://abload.de/img/bicubic6034rgk.png DXVA: https://abload.de/img/dxva1yu99.png the last thing i have to say about the DXVA nvidia scaler avoid it if possible... |
1st September 2017, 09:07 | #353 | Link | |
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It looks like it is probably just very uneven brightness between pixels when at low brightness. flat 5% gray However, I still don't think the banding is due to a lack of dithering. I think it is due to a much worse problem with this OLED TV not having a smooth response, e.g. there are visible steps between some 10 bit values but not between others or when zoomed in all the way on a luminance graph it would look like a slanted stair step (>90° "stairs"). Also it is not uniform spatially, on a solid 5% gray screen there are some obvious lines, squares, etc. Sorry, not madVR related.
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1st September 2017, 19:58 | #354 | Link |
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the sony, Phillips and the panasonic OLED have no real problem with banding so the issue comes down to low bit deep processing with dithering or high bit deep processing with out dithering.
don't forget an OLED needs heavy processing because it is WRGB. |
1st September 2017, 20:55 | #355 | Link |
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Yes, I am simply not sure it is a problem with dithering (or lack thereof), it may be simply bad processing. My expectation is that it would be better if the banding was only because it didn't dither. The visible banding is not evenly spaced in a gradient, it might have obvious banding at only a few transitions, which are randomly spaced and might involve more than one 10-bit value. The number and placement of the bands does change when changing settings like contrast or black level.
I think each pixel/panel probably responds a little differently and needs to be tuned to the right gamma curve and this tuning isn't complete enough, maybe they only do it at 100%, 70% and 40% and assume the panel is smooth between them when it isn't. You can see it when measuring the gamma curve in very finely spaced steps, slight under/overshoots as you move up the curve (~1.2 dE2000 at most but still visible when looking at what should be a smooth gradient). If 73% is undershooting luminance by 1dE and 77% is overshooting by 1dE you get visible banding even if 75% is nearly perfect. This seems to be worse with some colors too, an orange gradient's bands are more obvious but seem to have the same cause. I remember reading about the process of evening out pixel variations in the processing/display controller, LG was proud they had figured it out and it had a specific term which I cannot remember.
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3rd September 2017, 13:59 | #356 | Link |
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What is Compatibility in Display Mode Optimization section? My TV works even with very low compatibility rating after optimization. Does low compatibility mean worse image quality?
Also you stated that custom modes prevent 10bit depth unless 10-12bit is already enabled in NVidia CP, but doesn't madVR use some additional colors when 10bit is selected in madVR's Configurator? |
3rd September 2017, 16:55 | #357 | Link |
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Low compatibility means it may not work with many displays.
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3rd September 2017, 19:34 | #358 | Link | |
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Also these additional colors are inside the gamut, 100% RGB is the same color in 8 or 10-bit, 10-bit simply allows finer steps inside the same color gamut.
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4th September 2017, 15:18 | #359 | Link | |
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A. - Display set to 12bit (10bit functionality) in NVidia CP - Default/Non-Custom Display mode is used - madVR is set to 10bit OR B. - Display set to 12bit (10bit functionality) in NVidia CP - Custom Display mode is used - madVR is set to 10bit ? But I guess in the end it doesn't matter that much since madVR ED is really good. |
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4th September 2017, 20:18 | #360 | Link |
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It is hard to know without knowing which TV you are using. In your two tests all you are changing is whether or not you are using a custom display mode. B is better in this case.
The important point is what the TV does with 10-bit input. If it does internal processing at <10-bit sending 10-bit from madVR is usually worse, if your display does not handle 10-bit input well it might be better to have madVR dither to 8-bit because it is so much better at dithering. This is also an issue if your GPU is sending 8-bit to your display while madVR is sending 10-bit to the GPU, the GPU has to do the final dithering to 8-bit and the GPU isn't as good at it so it would be better to send it 8-bit. So make sure everything is really using 10-bit properly before setting it anywhere. Edit: I use these gradients to test with, does madVR 10-bit with dithering look better than without? If not I would set madVR to 8-bit. Never use madVR with the dithering off, except when testing. gradient-perceptual-colored-v2.1 24fps.mkv gradient-perceptual-v2.1 24fps.mkv
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