Blackmagic Forum

Thismorning, out of the middle of nowhere, I am seeing black blocky artifacts on various clips. Even after deleting the render cache and turning off all caching, the artifacts are still present, but they do not exist on the original media. Only when the grade is on do they appear. Even changing the grade settings in the nodes does not appear to have any affect on the artifacts. What is going on??

Happened to me also!!! I am running Mac OSX on High Sierra, with a GTX 980ti with no Cuda drivers (The Cuda drivers on High Sierra kept crashing my machine-- on non DaVinci things), and GPU set to Auto mode.
The black blocks happen on 15.2.3, but not any versions previous. I'm glad I duplicated the old version as Davinci Resolve 15.2.2.app before I did the upgrade. Made it much easier to debug.

The Black blocks were the only difference I saw between either version.

So I recommend that you downgrade, until the next update.

Michael McCaffrey wrote:This morning, out of the middle of nowhere, I am seeing black blocky artifacts on various clips. Even after deleting the render cache and turning off all caching, the artifacts are still present, but they do not exist on the original media. Only when the grade is on do they appear. Even changing the grade settings in the nodes does not appear to have any affect on the artifacts. What is going on??

What hardware (CPU, RAM, GPU, disk i/o)? What OS? What specific version of Resolve? What kind of source material (codec, bit-depth)? What timeline resolution?

There are many conditions where if you "push" 8-bit material too hard, you'll start to see compression artifacts and other problems. It might also depend on what cache file format you're using. If you use a low-compression HDR-capable format, the problem might go away.

Marc Wielage wrote:

Michael McCaffrey wrote:This morning, out of the middle of nowhere, I am seeing black blocky artifacts on various clips. Even after deleting the render cache and turning off all caching, the artifacts are still present, but they do not exist on the original media. Only when the grade is on do they appear. Even changing the grade settings in the nodes does not appear to have any affect on the artifacts. What is going on??

What hardware (CPU, RAM, GPU, disk i/o)? What OS? What specific version of Resolve? What kind of source material (codec, bit-depth)? What timeline resolution?

There are many conditions where if you "push" 8-bit material too hard, you'll start to see compression artifacts and other problems. It might also depend on what cache file format you're using. If you use a low-compression HDR-capable format, the problem might go away.

All that computer info is in my signature. And the codec I am using is mentioned in the video. DNxHR HQ

Marc Wielage wrote:

Michael McCaffrey wrote:This morning, out of the middle of nowhere, I am seeing black blocky artifacts on various clips. Even after deleting the render cache and turning off all caching, the artifacts are still present, but they do not exist on the original media. Only when the grade is on do they appear. Even changing the grade settings in the nodes does not appear to have any affect on the artifacts. What is going on??

What hardware (CPU, RAM, GPU, disk i/o)? What OS? What specific version of Resolve? What kind of source material (codec, bit-depth)? What timeline resolution?

There are many conditions where if you "push" 8-bit material too hard, you'll start to see compression artifacts and other problems. It might also depend on what cache file format you're using. If you use a low-compression HDR-capable format, the problem might go away.

I don't know about him, but I have the same exact problem. Editing on a 4k DCI Scope timeline. Source footage is Arri Alexa XT Raw that was conformed to Prores 444. Animorphic (2880x2160)

In Resolve Studio 15.2.3 I have same artifacts...


Same exact project, and same exact Render settings in 15.2.2:


Totally Clean.

Also, When you step frame by frame. the black blocks are in random places. Even stepping back and forth between the same frames.

My Specs are in Sig. I have no CUDA installed, as it makes the system crash randomly.

My Specs are in Sig. I have no CUDA installed, as it makes the system crash randomly.

but you have an invidia card??? does even work?

@Michael: Do they show up in renders and/or the GUI viewer?

@Benjamin: I've watched and watched your clip, and for the life of me, I can't see any artifacts. Could you give me a clue where to look in the image when, to get tuned into the artifacts?

If you're going to post a video, don't use a cellphone camera and shoot off a monitor. Take the actual clip and upload it to YouTube.

I am seeing a intermittent horizontal line of tiny black squares about a 1/3 of the way down -- is this what you're talking about? I would suspect a GPU malfunction, either overheating or not enough RAM, or maybe a driver problem.

waltervolpatto wrote:

My Specs are in Sig. I have no CUDA installed, as it makes the system crash randomly.

but you have an invidia card??? does even work?

It works great! Resolve has it on Auto mode, so it either uses Metal, or OpenCL.

Dwaine Maggart wrote:@Michael: Do they show up in renders and/or the GUI viewer?

@Benjamin: I've watched and watched your clip, and for the life of me, I can't see any artifacts. Could you give me a clue where to look in the image when, to get tuned into the artifacts?

Make sure your YouTube is set to 1080p. There are a bunch of random black dots. Like black dust on film.

Marc Wielage wrote:If you're going to post a video, don't use a cellphone camera and shoot off a monitor. Take the actual clip and upload it to YouTube.

I am seeing a intermittent horizontal line of tiny black squares about a 1/3 of the way down -- is this what you're talking about? I would suspect a GPU malfunction, either overheating or not enough RAM, or maybe a driver problem.

Not a GPU malfunction, overheating or anything like that... It is in a wel ventalated case, and the 2 renders were taken 2 minutes appart. It doesn't matter if it is a clead reboot, or if the system is up for hours. This is a BUG that was introduced in 15.2.3, as 15.2.2 works perfectly!

@Benjamin: Sorry, still can't see black dots in 1080HD mode.

At any rate, make a project with just that clip, and do whatever you need to do for the black dots to appear, then in the project manager page, export a project archive, and post that on a file sharing site and provide a link to the .dra file. You may need to zip the .dra first as some file sharing sites don't like the .dra format. Hopefully we can reproduce the issue, and figure out what's going on.

Dwaine Maggart wrote:@Benjamin: Sorry, still can't see black dots in 1080HD mode.

At any rate, make a project with just that clip, and do whatever you need to do for the black dots to appear, then in the project manager page, export a project archive, and post that on a file sharing site and provide a link to the .dra file. You may need to zip the .dra first as some file sharing sites don't like the .dra format. Hopefully we can reproduce the issue, and figure out what's going on.

Ok, So I took that clip, and exported it in Source Res, H264 QT-Flat Pass, and I also exported a still.. I then created a new project, imported the Flat Pass clip, and put it in a timeline. I also imported the Still. Then in the Color tab, I applied the grade from the still... And, I have the random black dots on 15.2.3. I do not on 15.2.2.

So I rendered out the clip from both Resolve versions, and the 15.2.3 has the Black dots, and the 15.2.2 don't.
https://www.dropbox.com/s/skgckzocdin7m ... g.zip?dl=0
I included everything in the project and the outputs.

The Project was shot with Arri Alexa XT with Panavision Lenses in Animorphic to Arri RAW, then the DIT converted the RAW to Prores 444 with Resolve on site to save space, with a ProRes LT as source Resolution for offline editing & backup if the 444 was a bad transcode. The clip I used originally was Prores 444, but the H264 render of is does the same exact thing. So It isn't the Prores Codec.

Ok, I booted into Windows 10, and I installed 15.2.2, and loaded the project, rendered out with the GPU set to Auto, Cuda, and OpenCL.

In 15.2.2 -- All clean, and all match.

In 15.2.3, Auto & CUDA had some random black dots. OpenCL had a about 10x more though.

Here are the renders from Windows:
https://www.dropbox.com/s/gpm3ybdc9rjml ... t.zip?dl=0

So, since it is in both Mac and Windows, and in OpenCL, and Cuda. And it is Clean on 15.2.2 on both, Something in the 15.2.3 broke it.

Benjamin McGuire wrote:

Dwaine Maggart wrote:@Benjamin: Sorry, still can't see black dots in 1080HD mode.

At any rate, make a project with just that clip, and do whatever you need to do for the black dots to appear, then in the project manager page, export a project archive, and post that on a file sharing site and provide a link to the .dra file. You may need to zip the .dra first as some file sharing sites don't like the .dra format. Hopefully we can reproduce the issue, and figure out what's going on.

Ok, So I took that clip, and exported it in Source Res, H264 QT-Flat Pass, and I also exported a still.. I then created a new project, imported the Flat Pass clip, and put it in a timeline. I also imported the Still. Then in the Color tab, I applied the grade from the still... And, I have the random black dots on 15.2.3. I do not on 15.2.2.

So I rendered out the clip from both Resolve versions, and the 15.2.3 has the Black dots, and the 15.2.2 don't.
https://www.dropbox.com/s/skgckzocdin7m ... g.zip?dl=0
I included everything in the project and the outputs.

The Project was shot with Arri Alexa XT with Panavision Lenses in Animorphic to Arri RAW, then the DIT converted the RAW to Prores 444 with Resolve on site to save space, with a ProRes LT as source Resolution for offline editing & backup if the 444 was a bad transcode. The clip I used originally was Prores 444, but the H264 render of is does the same exact thing. So It isn't the Prores Codec.

Did you happen to use Spatial NR (Faster Mode) in this clip?
I have seen this with the new version. There is a topic here
viewtopic.php?f=21&t=85267

I have downloaded and tested your project and I can confirm the black specks on my system.

And yes, they appear to be caused by Spatial NR used in Faster mode. Disabling Spatial NR or setting it to any other mode makes the specks disappear for me.

Christian Lessner wrote:And yes, they appear to be caused by Spatial NR used in Faster mode. Disabling Spatial NR or setting it to any other mode makes the specks disappear for me.

Ah, that could well be the culprit. The o.p. never mentioned using any NR. That's a major clue, and I'm sure there'll be a fix for it.

Dwaine Maggart wrote:@Michael: Do they show up in renders and/or the GUI viewer?

@Benjamin: I've watched and watched your clip, and for the life of me, I can't see any artifacts. Could you give me a clue where to look in the image when, to get tuned into the artifacts?

Hi Dwaine,

Yes the blocks do appear in the GUI in both the edit pages and deliver page and appears when rendering and in the rendered file (DNxHR HQ).

Concerning the Spatial Noise Reduction that was mentioned earlier, yes I do have some Spatial NR happening. By default it is set to "Faster." When I switched it to "Better" the blocks went away. When I switched it to "Enhanced" the footage was still clean (no blocky artifacts). So it does indeed seem to be related to Spatial NR.

Christian Lessner wrote:I have downloaded and tested your project and I can confirm the black specks on my system.

And yes, they appear to be caused by Spatial NR used in Faster mode. Disabling Spatial NR or setting it to any other mode makes the specks disappear for me.

Sweet!! So we now all know what bug needs to be squashed

I will continue to stay on 15.2.2 until 15.2.4 or 15.3, or 16 comes out.. Whatever fixes it in a future version

I never found the fast spatial NR very helpful, since it also squashes detail more than the others.

Uli Plank wrote:I never found the fast spatial NR very helpful, since it also squashes detail more than the others.

That's true but sometimes noise can be so bad its a necessary evil and the lesser of two evils.

Michael McCaffrey wrote:

Uli Plank wrote:I never found the fast spatial NR very helpful, since it also squashes detail more than the others.

That's true but sometimes noise can be so bad its a necessary evil and the lesser of two evils.

the "best" is ok, but the "enhanced" is really good

This should be addressed in the next release.

In the mean time, either don't use Fastest, or, don't use Small Radius.

Or revert to 15.2.2.

I'm not sure if you are stating the problem only exists when using the combination of Faster AND Small. It seems to exist using Faster regardless of other option.

This should be fixed in the 15.2.4 release that was just posted.

Thank you, this seems to work correctly now. I have found that 'fastest' works quite well in low light noisy log shot footage.

Bumping this up again

This exact same thing is now happening in 18.1.2

I searched for hours today and finally found this topic and freaking thank you everyone here!

When I seen this and I went to the optical flow and changed Motion Estimate Mode from Standard Better (Which actually was working extremely better than Enhanced faster and better for some reason....this is also a current issue.....so side note, Enhanced Faster and Better break the processing and regardless if lowest resolution, optimized media and or Proxy....it won't play back and just glitch)

Anyways, I changed it back to the lowest one standard faster and bam.....fixed.

So 18.1.2 Optical flow is broken in 3 out of 4 modes.

This whole thread was about spatial NR, not optical flow.
Be kind enough to start a new thread and add an example.

Actually this whole thread was about those artifacts and someone had mentioned Spatial NR half way through, so this is the correct thread just the same issue is now in a different spot

I made sure I read the whole thing first Since it was relevant to my issue and that queued me into checking the optical flow which ended up being the new issue/fix.

I disagree. I read the whole thread and the issue being discussed was narrowed to a bug in the 'Faster' spatial NR. Nothing to do with optical flow. It's up to you, of course, but if you would like BMD eyes on this, I agree with Uli that you should probably start a new thread.

Ayaa.

I obviously stated that in my first reply. Thanks for trying though. Well correction, I could have said, that temporary fix lead me to checking optical flow since it literally is the same options with the standard faster better etc.

But It's the same issue, but created in a different spot. If you would like, you can ask them to change the title, since again, it's the same issue with literally everything exactly the same as the initial post, with a different reason creating the bug.

Therefore it would also go here.

You don't create new threads on the exact same problem just because there is a different issue creating the same bug. So now there is two answers from two different issues creating the same exact artifacts in the correct thread. There would be 1234235 threads with single answers to someone else's post and no one would even be able to link all of them together.....literal face palm.

So you should probably just unsubscribe this if you don't want to see it.

It's well known from medicine that the same symptom can have very different causes. I think you wouldn't be happy if a doctor would always use the same treatment without checking the real cause.

Nuff said, good luck.

Most Medical issues have multiple causes, which strengthens my point, thanks.

But that's enough bickering back and forth, if you don't like the antidotes, don't take them. But since this is the only thread that actually pointed me in the right direction. So Hurray, here we are

Lol

hope the problem is resolved for you guys..i am also facing this issue in resolve 18.1.4 build 9 but my timeline is ACES 1.3 so as soon as i shift it to 1.2 it disappears only issue is 1.2 there is no gammut Compression