DaVinci h264 media shows gamma shifting when Playing/Pausing

Question

Level 1

108 points

DaVinci h264 media shows gamma shifting when Playing/Pausing

I have some h264 footage that was rendered out of DaVinci Resolve that exhibits a gamma shift when playing back the footage in FCPX or Motion. Any other program, Ae, Pr, Compressor, Resolve, does not show this shift when playing back. I am still on Big Sur, and can't update to Monterrey.

ProRes Media from Resolve also does not show this issue, so far only h264 or h265 out of Resolve.

Other h264 media also does not show this issue, only media from Resolve. I feel like this is a two pronged problem, and not sure if DaVinci or Apple is the issue. Since the media works in other programs, including Compressor, it seems to point to Apple.

Thanks for any advice.

MacBook Pro 16″, macOS 11.6

Posted on Nov 28, 2021 9:01 PM

Reply

Answer 1

JeremyG Author

Level 1

108 points

Nov 29, 2021 8:42 AM in response to Tom Wolsky

The title of this post says "when playing/pausing". Stop and start. :)

When paused, the image is normal (that's the brighter of the image). When scrubbing, it goes darker, and when I stop is goes dark, and then shifts to normal. But, if the image is already dark, I can play and the image stays dark. Also, when adding a filter, like color correction, the image goes dark. The darker of the two states is not normal. The brighter of the two states is what the footage looks like. This happens on any footage that has been transcoded with DaVinci Resolve in to h264 or h265. ProRes footage from DaVinci does not exhibit this problem (as you can see on the first clip that I playback). The source of the footage does not seem to matter, I have transcoded, Sony F55, A7, and Phantom Flex footage, and it all exhibits the same behavior. It is either the way the DaVinci is making the h264 or h265 footage that FCP is "interpreting" wrong, or there's something wrong with FCP. As mentioned, the footage works just fine in other programs.

Reply

Answer 2

terryb

Level 4

3,370 points

Nov 29, 2021 9:27 AM in response to JeremyG

Not sure if this will be helpful in your situation, but here's a description of Resolve Rec709 and Rec709-A color space tags that affect gamma interpretation in QT. https://www.thepostprocess.com/2020/07/17/color-on-mac-displays-from-davinci-resolve-to-the-internet-with-quicktime-tags/

Reply

Answer 3

Tom Wolsky

Level 10

152,780 points

Nov 29, 2021 3:07 AM in response to JeremyG

Is the Display Color System Preferences set to the default?

Reply

Answer 4

Tom Wolsky

Level 10

152,780 points

Nov 29, 2021 5:45 AM in response to JeremyG

I’m sorry, so the Display Color System Preference OS set to the default, put it isn’t?

Could you post screenshots of the difference you see in the applications?

Did you try 10-bit HEVC to see if that has the same issue?

Reply

Answer 5

Tom Wolsky

Level 10

152,780 points

Nov 29, 2021 8:01 AM in response to JeremyG

I've never seen anything like this. This is more than gamma; this is whole exposure change. So the problem is in the stopping and starting. I didn't understand that before, that the image changes when you start and stop. You're clicking the spacebar so often I can't tell what's happening. When does it look correct, when you're stopped, or when it's playing. It seems it becomes dark when you're playing back. What are the complete media specs, resolution and frame rate? What's the spec of the original media.

Reply

Answer 6

JeremyG Author

Level 1

108 points

Nov 29, 2021 5:11 AM in response to Tom Wolsky

Yes. I have updated all plug-ins, uninstalled old software, I have trashed prefs, reinstalled, everything I can think of to try and solve it. It’s strange that FCPX and motion show the issue, and compressor doesn’t.

Reply

Answer 7

JeremyG Author

Level 1

108 points

Nov 29, 2021 7:43 AM in response to Tom Wolsky

Yes, h264 or h265. Display is set to default. This doesn't have to do with display. Here's a screen recording of what is going on. The first clip is ProRes, the second clip is h265, both encoded out of DaVinci Resolve. Please note the gamma flashing on the h265 media (this also happens with h264 media from DaVinci Resolve) when starting and stopping as well as scrubbing in Viewer.

https://www.dropbox.com/s/tpmqe9r4lbrk7bi/DavinciMedia.mov?dl=0

Reply

Answer 8

Tom Wolsky

Level 10

152,780 points

Nov 29, 2021 8:59 AM in response to JeremyG

Sorry about that mistake. I'm used to news writing rules.

What are the original specs? Are they XAVC? It seems very strange. I don't do Resolve, perhaps Ian Brown or others who work with it can add something on there experience.

Reply

Answer 9

JeremyG Author

Level 1

108 points

Nov 29, 2021 9:43 AM in response to terryb

Thank you. The footage plays back just fine in QT without the gamma shifts. When looking at the footage paused, the files match exactly in terms of gamma and color. It is only this footage, when playing back, do these shifts occur, and then it turns on and off dynamically. This isn't a case of getting a movie to display the same across all devices, this is some sort of playback bug or issue. Appreciate the link!

Reply

Answer 10

JeremyG Author

Level 1

108 points

Nov 29, 2021 9:02 AM in response to Tom Wolsky

Original Specs are XAVC MXF, XAVC mp4, Phantom.Cine, ProRes, it literally does not matter what goes in to Resolve, it is only what comes out, specifically, the h264 or h265 mov.

Reply

DaVinci h264 media shows gamma shifting when Playing/Pausing

Similar questions