Re: [Avid-L2] IMF DolbyVision Metadata version mismatch in Resolve?

On Sat, Feb 20, 2021 at 10:23 AM, David Baud wrote:

Can you share a screen grab of your Project settings for Color Management in DaVinci Resolve?

 

Unless the studio have a specific requirements for this project, most will ask you to make an IMF master that is SMPTE 2084 (PQ) compliant but limit your color space to P3-D65. What it means is right now there is no HDR monitors capable to show you the full Rec. 2020 color space. In order to prevent any unwanted gamma excursion, you are limiting to the smaller P3 color space.

 

David Baud

Colorist & Finishing Editor

david at kosmos-productions.com

With the Mastering Display set to P3 I don't get an error:




If I set Mastering Display to Rec 2020 I get the error after toggling between custom metadata, of which there is none, and embedded metadata in the DolbyVision Tab.


This is the error it displays:



 I am running with separate color space and gamma checked because during my HDR IMF onboarding for Netflix without that checked and set to P3 and ST 2084 1000 Nits I would end up with approx half video level when exporting an IMF.  Netflix Tech support gave me a tutorial video that showed I need to use separate color space and gamma to overcome what appears to be a bug in Resolve.  Here is a link Netflix Tech gave me to guide in setting up the project.  Here is a video
I'm not sure when separating the color space and gamma what difference setting the gamma to 2084 or 2084 1000 Nits does.  I see no change in output to my HDR LG OLED and my Target Display PVM-2541 Sony.  I'm not really clear on what setting the timeline color space and gamma does to the actual video essence.  Is it correct that setting the timeline color space and gamma tell the rest of the Resolve color path how to transform the signal to other target color spaces and gamma.  If I see no change when togging from gamma 2084 to 2084-1000 Nits is that because there are no color transforms in the rest of the food chain?  At it's core I'm wondering what setting the timeline color space and gamma does to image processing.

 

On Feb 20, 2021, at 2:21 AM, John Moore <bigfish@pacbell.net> wrote:

I know this is an Avid list but many of you are more versed than I am in the world of Resolve.  I've emailed my Resolve HDR classmates with this but thought maybe someone here might have some insight.  The need to deal with DolbyVision, IMFs and the ever changing HDR landscape has me looking into what's really going on under the hood.  Here's what I sent to my HDR class:

 

Taking an out of house IMF which I imported the embedded DolbyVision metadata from the IMF into a Resolve 16.2.7 project.  The IMF file is "BethStelling_GirlDaddy_DolVis40-rec2020pq_3840x2160_23976_16ch-ENG_200903".  I have set the mastering display setting in the project to Rec 2020 D-65 1000 nits but I intermittently get this error message:

 

<1613811284928blob.jpg>

 

 

If however I set the mastering display setting to P3 D-65 1000 Nits I don't seem to get this error popping up.  I looked through the IMF .xml files to see if I could find some text that would confirm what the dolbyvision metadata really is.  The file name would imply the DolbyVision 4.0 at Rec 2020PQ but that causes the above error message.  It would sure be helpful if Resolve would just indicate what the DolbyVision Metadata is to alleviate all this unnecessary guess work.  The error seems to only pop up when I switch from custom metadata, of which there is none, to embedded metadata but it doesn't happen every time I switch.  Is there a way to visually parse through the .xml files in the IMF to find some English text that will describe what the specs of the DolbyVision metadata is in the IMF?