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Request for a Dolby vision pluge pattern #4
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I've added Black PLUGE pattern in DV to the experimental downloads section, so you can download it As you might have seen in the sources the full list of patterns the project has is almost ready in DV for quite some time, but unfortunately I've had no enough time to do some final checks and adjustments. Hopefully I will find it sooner than later. Concerning the white clipping - it is an interesting problem on what those patterns should be. I definitely have those patterns in mind (for all the SDR/HDR/DV sets) but dynamic metadata adds a new dimension to them. What actually would you want to test with them in DV? Is it that DV correctly maps all light range of the scene to the TV capabilities given the metadata correctly presented? Is it finding the point where it actually clips given the metadata is at the TV capabilities or below them? For HDR it is also an interesting problem (that would logically only depend on Max Content Light Level meta, but in practice sometimes depend on Mastering Display Max Luminance meta)... For SDR it is simple - you are just finding at what code point it clips. For HDR/DV I would like to be discussed what patterns do we really need (re. Mastering Monitor meta, HDR10 Content (global) meta and DV Content (per frame) meta). |
Hi Igor,
Thank you very much for the DV pluge pattern. I have had a major issue with
blacks on my LG C8, and your pattern exposed it instantly!
Some background:
I live in India, and don't have access to any professional calibrators
nearby, so the best I can do (without spending a bomb on calman +
equipment) is to use test patterns and make basic settings to the panels I
use.
For SDR: I've relied on the black level, white/contrast level, and color
clipping patterns from here:
https://www.avsforum.com/forum/139-display-calibration/948496-avs-hd-709-blu-ray-mp4-calibration.html
I adjust brightness till I can see bars 17 and above glow (black clipping
pattern), and not clip earlier
I adjust contrast till i can see bars up to 234 glow (white clipping
pattern), and not clip earlier
I also adjust colour till I see all the 3 primary RGB colors glow till 234
(color clipping pattern), and not clip earlier
For HDR: I've relied on the black level, white & color clipping patterns
from here:
https://drive.google.com/drive/folders/1UnPiHQrJjldIPbfVwt95S7ck0tvR4yUM
https://drive.google.com/drive/folders/17z94AGSQN7m0VLS1oDEkViQlr0wvpWhG
I adjust brightness till I can see bars 68 and above glow (black level
patterns), and not clip earlier
I adjust contrast till i can see my TV tone map correctly to 1000 nits
(white 240-1000 nits pattern), and not clip earlier
I also adjust color till I see all my TV tone map all colors correctly up
to 1000 nits (01. 240-1000 nits pattern), and not clip earlier
For Dolby vision, however, I had no access to any such patterns, till I
came across your thread.
*Now onto why your patterns interested me the most:*
My LG C8 is notoriously bad at handling dark greys or near black regions,
irrespective of SDR, HDR or Dolby Vision
I constantly see garbage, macroblocking, what they now call
near-black-chrominance-overshoot, etc, so I've been on a quest to sort this
out.
Your SDR and HDR pluge patterns gave me the biggest break at some amount of
relief from this TV.
What I ended up doing with your pluge patterns is eliminated the TV from
displaying the first visible grey bar (from the left) out of 2 grey bars
that are mandatory to be displayed.
So for SDR, by eliminating the first grey bar using your pluge pattern, in
the Technicolor preset, I went from from an ideal world (no black crush)
Brightness = 50, Contrast = 85, to Brightness = 48, Contrast = 85.
This resulted in clipping the black bars 17 & 18 (19 and above glow) in the
AVS pattern.
For HDR, by eliminating the first grey bar using your pluge pattern, in the
Technicolor preset, I went from an ideal world (no black crush) Brightness
= 50, Contrast = 100, to Brightness = 50, Contrast = 97
What's interesting here is a brightness of 49 resulted in both grey bars
being crushed, but keeping a brightness of 50 and reducing contrast to 97
did the job.
This resulted in clipping the black bars 68 & 72 (76 and above glow) in
Mehanik's patterns.
Now, people may argue that I'm crushing black, but honestly, I'm so tired
of seeing garbage on the TV in dark scenes, that this compromise is
absolutely perfect.
And I don't think the black crush is much to be honest, I continue to see
good shadow detail in the dark.
I pretty much fixed my SDR and HDR issues. After these settings, I never
ever saw garbage or bad-near-black-level handling in any situation SDR or
HDR content again.
But I continued to see garbage in Dolby vision, and the garbage in Dolby
vision is so bad, that I cannot even explain it accurately.
Most times, in dark scenes in Dolby vision, the entire screen fills with
what feels like a constant moving wave pattern that looks like snow+dirt
mixed, from the right bottom of the TV, to the top left.
This ridiculous pattern is even constantly visible when you pause the
content!
While I wanted to apply the same HDR settings blindly to DV, I also wished
for a pluge pattern to ensure I was doing the right thing.
And that's when I requested for such a pattern from you, and your pattern
instant showed that constant moving wave pattern of snow+dirt, confined
exactly within the first grey bar of your DV pluge pattern.
I tried to take videos of this with multiple phones, but the image is
already so dark, that no phone (that I have access to) is able to capture
this correctly.
For DV, I was able to eliminate the first grey bar and yet display the
second grey bar by using a brightness of 49, contrast = 100. This was
unlike HDR, where brightness 49 crushed both black bars.
But, believe it or not, the ugly moving wave pattern of snow+dirt moved to
the second grey bar as soon as I eliminated the first grey bar with a
brightness of 49.
After playing around a bit, I found that these settings eliminated the
first grey bar, yet also ensured the ugly moving pattern does not move to
the next bar.
In Cinema Home preset, brightness = 49, contrast = 99
In Cinema preset, brightness = 50, contrast = 97
Hope this helps answer your questions, and thank you again for all the hard
work.
Cheers,
Vivek
…On Wed, Feb 13, 2019 at 9:52 PM Igor Malinin ***@***.***> wrote:
I've added Black PLUGE pattern in DV to the experimental downloads
section, so you can download it
here
<https://github.com/testing-av/testing-video/releases/download/v0.0.1-alpha/BlackPLUGE.U4K_DVp5.mp4>.
Let me know if it works well and on what TV set / media player.
As you might have seen in the sources the full list of patterns the
project has is almost ready in DV for quite some time, but unfortunately
I've had no enough time to do some final checks and adjustments. Hopefully
I will find it sooner than later.
Concerning the white clipping - it is an interesting problem on what those
patterns should be. I definitely have those patterns in mind (for all the
SDR/HDR/DV sets) but dynamic metadata adds a new dimension to them. What
actually would you want to test with them in DV? Is it that DV correctly
maps all light range of the scene to the TV capabilities given the metadata
correctly presented? Is it finding the point where it actually clips given
the metadata is at the TV capabilities or below them? For HDR it is also an
interesting problem (that would logically only depend on Max Content Light
Level meta, but in practice sometimes depend on Mastering Display Max
Luminance meta)...
For SDR it is simple - you are just finding at what code point it clips.
For HDR/DV I would like to be discussed what patterns do we really need
(re. Mastering Monitor meta, HDR10 Content (global) meta and DV Content
(per frame) meta).
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Request for a Dolby vision pluge pattern to set correct black level on LG OLED TVs. I personally own a LG C8 and have found your SDR and HDR pluge patterns to be incredibly useful.
In the future, if you could also help include some patterns in SDR, HDR and Dolby vision - for white clipping (0-1000 nits & 1000-4000 nits) and colour clipping (0-1000 nits & 1000-4000 nits), that would be even more awesome.
Thanks.
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