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But HLG is not that popular. Only one HLG channel on Youtube. And anyway, it is even harder to present. And somehow everybody does not understand that HLG has SDR layer that should be presented on SDR displays and instead color manage HLG laywer. Hillarious.
It’s the broadcast standard in, at least, the UK and US.

It’s not “popular” for recorded content because it doesn’t add as much value there, but that’s really irrelevant.
 

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Yes, in fact, using an HDfury Vertex 2 (or similar other device from them) you can force an LLDV Sony EDID
Unfortunately that is also broken (as in all Blu-ray players) because of bad Dolby SDK (except Nvidia Shield, AFAIK, that has a very different bug too though, partially fixed by removing BT.2020 flag, mastering flag (?)) has a bug that makes LLDV different from Standard.
 

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Discussion Starter · #24 ·
Unfortunately that is also broken (as in all Blu-ray players) because of bad Dolby SDK (except Nvidia Shield, AFAIK, that has a very different bug too though, partially fixed by removing BT.2020 flag, mastering flag (?)) has a bug that makes LLDV different from Standard.
I haven’t really noticed any appreciable difference between my Apple TV LLDV output, and the streaming apps directly on my C9 TV. I wonder if the broken LLDV is more related to 12-bit Profile 7 FEL discs on blu-ray players, rather than the 10-bit profile 5 files that are on streaming services.


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@firecore Can you like fix that HDR wrong metadata issue? Or zero it out so that it will be "unknown" (see latest SMPTE ST 2086:2018)? Dunno. In that case it should recalculate them. Blu-ray spec says the values should be calculated from the video stream without the black borders... those 4000/1000 as all others on other videos should be precise to all digits.
We had looked into this previously, and unfortunately there weren't any options for adjusting these fixed values. We're going to comb through things in tvOS 14.5 just to be sure, but as of right now there isn't a great option here.

IIRC, there were a few similar cases in the past with some LG models that seemed to be solved by setting the output chroma to 4:2:0 instead of 4:2:2. This may have been for SDR/HDR and not DV though.
 

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BTW, there is a giant thread right there:


I will remind you that static metadata is allowed to change as per CTA-861-G, so it was a non-issue, except well, metadata should not change on frame basic, that will be too obvious, while Dolby Vision as in iPhone 12 is allowed to change on frame basic, which it does, BTW. Static metadata can only change on scene basis.
 

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Here are Alien, The Greatest Showman, and Logan respectively, via iTunes.
Can you check this: https://gitlab.freedesktop.org/gstr...oads/16c628c535865d7282a48317064345a2/out.mp4

It should change from HDR metadata:

max_content=284
max_average=145

to
side_data_type=Content light level metadata
max_content=378
max_average=277

as scene changes. @firecore You may be also interested. That is what Apple does on DV to HDR10 conversion anyway, so it should be supported. You can check it in MadVR that indicates change of max_content.
 

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Reading through this as a potential buyer of AppleTV 4K. I have LG C8 OLED, this is one of the devices that will exhibit raised black levels with Dolby Vision?
 

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Discussion Starter · #29 ·
Reading through this as a potential buyer of AppleTV 4K. I have LG C8 OLED, this is one of the devices that will exhibit raised black levels with Dolby Vision?
Yep, every generation is affected.


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2) Near Black SDR Flickering
  • When playing back SDR content, there is very noticeable flickering in near black areas of the image. It's MUCH more noticeable when match frame rate is enabled with 24p/25p content (when output at 24Hz and 25Hz) then it is with 50p/60p content, my guess is because it is flickering less rapidly, and therefore more noticeable to the eyes.
  • This flickering is a video output issue, it happens even when a video is paused, and even is noticeable in the UI in certain circumstances, it is not just flickering in the content itself.
  • Switching the UI to 60Hz YCbCr 4:2:0 makes the issue pretty much completely disappear when in the UI, but when in YCbCr 4:4:4 60Hz, it is still there just nearly unnoticeable. However, even with match frame rate disabled, when content starts, the Apple TV switches to 4:4:4 60Hz, even if the UI is set to 4:2:0 60Hz.
  • Switching to RGB Low, or RGB High, reduces this issue quite a bit, but there is still some flickering
  • This issue is present no matter what output resolution is set, 720p, 1080p, 4K etc.
  • This issue is not limited to just the Apple TV 4K, it seems like all relatively recent Apple Silicon based devices have this issue, I've personally tested the Apple TV 4K, iPad Pro 2018 w/ USB-C AV Adapter, and a 2020 M1-Based MacBook Air, and it's there in the video output of all three of them
  • This issue is NOT present on the older 4th Gen Apple TV HD or older Intel-based Macs, both output a clean non-flickering image at low frame rates.
  • I only own LG OLEDs (currently a B7, C9, and CX), so I'm not sure if this is specific to them or not (I can't imagine it is though), and would like other users to test this for themselves, and let me know what you find
  • Here is a link where I attempt to show the issue, but it's kinda hard to capture (Ignore the fact that the video is in HDR, the Apple TV was outputting in SDR at the time I took the video):
YES!! I have this exact same issue. It has been driving me crazy as it was happening on my LG CX and happens on my Sony A8H as well.

I've seen other reports of it, but there is no widespread information on exactly what causes it. Like you, if I change YUV to 4:2:0 or RGB High/Low the problem becomes tolerable and it's much less obvious, but I want to know why this is happening on YUV 4:4:4 as that's what is generally recommended to use.

Exactly like yourself I have no issues whatsoever with the internal apps on the TV and don't notice any intense flickering on my PS5 or Satellite Box. The Apple TV 4K however is so bad in YUV 4:4:4 that even pausing certain darker content or greys causes the screen to keep flashing and flickering.
 

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Discussion Starter · #33 ·
YES!! I have this exact same issue. It has been driving me crazy as it was happening on my LG CX and happens on my Sony A8H as well.

I've seen other reports of it, but there is no widespread information on exactly what causes it. Like you, if I change YUV to 4:2:0 or RGB High/Low the problem becomes tolerable and it's much less obvious, but I want to know why this is happening on YUV 4:4:4 as that's what is generally recommended to use.

Exactly like yourself I have no issues whatsoever with the internal apps on the TV and don't notice any intense flickering on my PS5 or Satellite Box. The Apple TV 4K however is so bad in YUV 4:4:4 that even pausing certain darker content or greys causes the screen to keep flashing and flickering.
It seems to be some combination of poor near black handling on OLEDs and the constantly fluctuating video output on the ATV4K. I think getting a highly accurate professional calibration can help with the issue, but I’ve also come up with some settings (trying to replicate a reference mode without calibration) on my B7 and C9 that make it undetectable to my eyes from normal viewing distances:

LG TV Settings:
-Cinema or ISF Expert Dark picture mode
-OLED light 25-30 (targeting SDR 100 nits peak white)
-Gamma 2.4
-Sharpness 0

ATV4K:
-RGB High

Give these settings a shot, and let me known if you still see the flickering in your LG TV? I’ll admit it might be a bit too dark for bright rooms though.


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It seems to be some combination of poor near black handling on OLEDs and the constantly fluctuating video output on the ATV4K. I think getting a highly accurate professional calibration can help with the issue, but I’ve also come up with some settings (trying to replicate a reference mode without calibration) on my B7 and C9 that make it undetectable to my eyes from normal viewing distances:

LG TV Settings:
-Cinema or ISF Expert Dark picture mode
-OLED light 25-30 (targeting SDR 100 nits peak white)
-Gamma 2.4
-Sharpness 0

ATV4K:
-RGB High

Give these settings a shot, and let me known if you still see the flickering in your LG TV? I’ll admit it might be a bit too dark for bright rooms though.


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Thanks mate. My main TV is a Sony A8H now, so I'm not sure how to make it better on here.

The issue is absolutely much worse with lower bitrate content than 4K stuff, but I don't know why with the Apple TV it keeps flashing flickering even when a video like that is paused? It must be something to do with the Apple TV as I've tried watching a movie on the PS5 and internal apps and I don't get any of the raised black rubbish and they have miniscule to non-existant posterisation and flickering when watching from a regular distance. Using 4:2:0 Chroma instead of 4:4:4 or using RGB High or Low seems to mostly stop the menu flickering.

The Apple TV even flickers on certain menu screens like the Youtube search screen. The banding and vignetting on my TV is totally acceptable, so I don't want to risk returning this TV for something I'm only significantly noticing from an Apple TV 4K and it happen on my new TV as well.
 

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Thanks for starting this! I have reported and talked to an Apple rep on Reddit who said he’ll pass on the info and stated that they also have multiple OLED’s in house to test but I haven’t heard back in a while. I reported through Apple as well. Hopefully this gets resolved as this is one of my favorite streamers. Hopefully Hulu 5.1 gets added and maybe HDR YouTube in the next gen, otherwise it’s perfect for me.


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Thanks for starting this! I have reported and talked to an Apple rep on Reddit who said he’ll pass on the info and stated that they also have multiple OLED’s in house to test but I haven’t heard back in a while. I reported through Apple as well. Hopefully this gets resolved as this is one of my favorite streamers. Hopefully Hulu 5.1 gets added and maybe HDR YouTube in the next gen, otherwise it’s perfect for me.
As someone who works for one of these companies myself, I would be strongly recommending everyone with this issue makes Apple, LG & Sony aware. Nothing will happen unless people report it.
 

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I am also having the "Near-Black SDR Flickering" as well on the Apple TV 4K.

Here's a demonstration of the most obvious flickering, at 1080p60 SDR in the Apple TV UI itself, right under the "Apple TV Switched ..." text. (Make sure you're viewing it the highest quality level)


This is a direct chain from the Apple TV to a capture card, though the YouTube compression softens it partway through, it is consistent in the source video. It does indeed affect dark scenes as well. No amount of fiddling with framerate, chroma, or "Match Content" settings seems to make a difference (I don't have a 4K capable setup to inspect the image at 4K correctly, but the same flickering exists at 4K perhaps less apparently).

With the 2021 Apple TV coming out, I'm wondering if this has been corrected in the new version. I'm a little pessimistic since the first post mentions M1 based Macs and the Apple USB-C AV Adapter also have this issue..

I tried a while back to submit feedback on Feedback - Apple TV - Apple but I didn't expect to get a response.
 

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I am also having the "Near-Black SDR Flickering" as well on the Apple TV 4K.

Here's a demonstration of the most obvious flickering, at 1080p60 SDR in the Apple TV UI itself, right under the "Apple TV Switched ..." text. (Make sure you're viewing it the highest quality level)


This is a direct chain from the Apple TV to a capture card, though the YouTube compression softens it partway through, it is consistent in the source video. It does indeed affect dark scenes as well. No amount of fiddling with framerate, chroma, or "Match Content" settings seems to make a difference (I don't have a 4K capable setup to inspect the image at 4K correctly, but the same flickering exists at 4K perhaps less apparently).

With the 2021 Apple TV coming out, I'm wondering if this has been corrected in the new version. I'm a little pessimistic since the first post mentions M1 based Macs and the Apple USB-C AV Adapter also have this issue..

I tried a while back to submit feedback on Feedback - Apple TV - Apple but I didn't expect to get a response.
I agree continued problems sound likely based on the M1 experience (for the SDR flicker). I am quite interested in that result as I would like to get the new ATV 4K.
Assuming this is Si based problem, it may not be fixable on existing Si (IE any products you purchased already), but a firmware fix could improve on the selectability of avoiding 4:4:4 if that exacerbates the problem?
 

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Well... on the back of this post I walked a few blocks to the electronics store today and picked up a new AppleTV 4K.

And, to my eyes, the Dolby Vision problem does seem to be resolved on the new hardware. I was not expecting this, and am pretty stoked.

I've watched The Hunt for Red October and some For All Mankind in Dolby Vision tonight. Zero-black looked completely dark to me. Dissolves to black were as clean as could be.

(Also the new remote is lovely).
 

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Discussion Starter · #40 ·
Yep, I can confirm that the raised DV black level issue is resolved on the 2021 Apple TV 4K as well! The near black SDR flickering is not unfortunately though :(
 
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