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OlivierQC
Reel Rookie

Black clips at 85 for Dolby Vision output only (Realtek SOC)

Hello to all,

I'm new on this forum and I just want to say that I don't have a Roku yet, before buying one I would like to know if the Realtek RTD1319 has the same problem as my
my Zidoo Realtek RTD1619DR

This problem is a black clippings at 85 (2.4%) in Dolby Vision only, which results in a signal cut-off in the vicinity of black earlier than it should be on some
increments.

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Here is a GIF as an example only, of 2 images of 5 seconds each and which shows you an example of what is the loss of information in the dark zone with the Realtek SOC.

Untitled-1

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Here is a GIF with a Dolby Vision pattern test that shows the black clipping problem with the Realtek SOC.

GIF-test-pattern

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The big question is, do Realtek SOCs have a common black clip problem with Dolby Vision output ?

Have you noticed this kind of problem with your Roku, which uses a Realtek RTD1319 ?

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Download link of the Dolby vision pattern test free :

Thanks to the person who shared this DV test pattern

They're based on Mehanik HDR10 patterns which are freeware with an RPU slapped.

MKV:
https://mega.nz/file/5awBkb6L#fI3HZE28l90-JxPY-7xU0m1LAHiYXFTK2Wwo_mXmXNo

MP4:
https://mega.nz/file/ZP42iTxK#9wIBmkEqEy4o8ZszDn4NhriARe0qYRpEEH_wzjGHRSI



Thanks in advance for your help.

 

Oliver

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7 REPLIES 7
atc98092
Community Streaming Expert

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

The few things I've watched in DV were either on HBO Max or Disney+, using my Ultra 4800. I can't say I've noticed anything like this, but I have to also say I wasn't looking for it. Without comparing the image with my Shield, I have my doubts I'd even notice. My DV display is not in a light controlled room, and until winter gets here I'm always watching with ambient light in the room. If there's a test clip I could download with the test patterns, I could compare the two players. But I'm not going to pay for a test clip. Not important enough for me, even for 99 cents. 🙂

Dan

Roku Community Streaming Expert

Help others find this answer and click "Accept as Solution."
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I am not a Roku employee, just another user.
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OlivierQC
Reel Rookie

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Thanks for your expert answer Dan,

I don't have it myself.

I'll see if anyone else can tell us or maybe a Roku employee if they see this message and possibly have dolby vision test patterns

Thanks again to everyone,

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OlivierQC
Reel Rookie

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Hello Dan,

You have no more excuses to check if there is a problem with the Roku RTD1319 Smiley Happy

 

Download link of the Dolby vision pattern test free :

Thanks to the person who shared this DV test pattern

They're based on Mehanik HDR10 patterns which are freeware with an RPU slapped.

MKV:
https://mega.nz/file/5awBkb6L#fI3HZE28l90-JxPY-7xU0m1LAHiYXFTK2Wwo_mXmXNo

MP4:
https://mega.nz/file/ZP42iTxK#9wIBmkEqEy4o8ZszDn4NhriARe0qYRpEEH_wzjGHRSI

 

See you soon

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atc98092
Community Streaming Expert

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Got it! I'll look at it on my LG this afternoon after I've finished work for the day. Already copied onto my DLNA server so I can look at it via multiple players. 

Dan

Roku Community Streaming Expert

Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.

I am not a Roku employee, just another user.
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OlivierQC
Reel Rookie

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Thank you very much for your support,

Will you keep me posted on the results you get from your different readers?

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atc98092
Community Streaming Expert

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Yep, I can try my Ultra 4800, an Nvidia Shield Pro (2019 model, the latest) and the internal player on the TV.

Dan

Roku Community Streaming Expert

Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.

I am not a Roku employee, just another user.
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atc98092
Community Streaming Expert

Re: Black clips at 85 for Dolby Vision output only (Realtek SOC)

Well, that was less than successful. First, every way I tried to play that clip only switched the TV to HDR. It did not indicate Dolby Vision, even though MediaInfo reports it as a DV file. 

Anyway, what I did see was the clip looked identical through the Roku, the Shield, and the TV's internal player. I could faintly make out the black level flashing at 88, and if I tried to make the room a bit darker I believe I could see 84 flashing. 80 and below were all just black. 

Again, that's with the TV displaying HDR, not DV. I even played the clip directly from a USB stick to ensure my server wasn't doing anything, but the image was identical from either source. 

I've searched for some other DV test files, and I can find none that have the black level test. I have several DV test clips, but for the most part they are designed to show eye-popping color, not black levels. I have one DV file with some NASA space images. While it's difficult to say if there's different black levels on that video, I will say it appears virtually identical (and beautiful) on both the Roku and Shield, at least as best I can tell from watching it on one and then the other. 

One last comment. I have no idea if my TV (LG Nano85 55") is capable of displaying the black levels below 84. For me, that might be a limitation that I can't get past. I have one other DV capable TV, a Vizio, but it's a smaller screen (and less expensive) so I have my doubts it's capable of better performance than my LG.

Dan

Roku Community Streaming Expert

Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.

I am not a Roku employee, just another user.
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