How to calculate HDR metadata for a video

[nautilus7]

Hi, I am trying to create an HDR video and encode it in HEVC.

I want to calculate the hdr metadata for my video, that is the maxFALL and the maxCLL. Do you know of a way to calculate these metadata (especially the maxFALL)?

I have found this HDRStaticMetadata (https://github.com/HDRWCG/HDRStaticMetadata) calculator, but I am unable to compile it. Can somebody compile it please?

Is there any other way to calculate this maxFALL value?

[quabit]

Hi, I am trying to create an HDR video and encode it in HEVC.

I want to calculate the hdr metadata for my video, that is the maxFALL and the maxCLL. Do you know of a way to calculate these metadata (especially the maxFALL)?

I have found this HDRStaticMetadata (https://github.com/HDRWCG/HDRStaticMetadata) calculator, but I am unable to compile it. Can somebody compile it please?

Is there any other way to calculate this maxFALL value?You may be able to generally estimate it. How did you create the video you are encoding and what range do you think it covers roughly?


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[nautilus7]

Well, I am trying to create some test patterns actually, not a real video. Something like this:

http://thumbs2.imagebam.com/b6/42/09/3a4fc4666214163.jpg (http://www.imagebam.com/image/3a4fc4666214163)

It goes all up to 100% in luminance, so maxCLL should be 10000 nits, but what about maxFALL? Obviously, since all frames are the same in this test pattern, it's enough to calculate the average light level for one frame only. But how to do it?

In case it comes up too high, I might need to reduce the size of the gradient, to avoid any dimming from the TV.

[quabit]

Well, I am trying to create some test patterns actually, not a real video. Something like this:

http://thumbs2.imagebam.com/b6/42/09/3a4fc4666214163.jpg (http://www.imagebam.com/image/3a4fc4666214163)

It goes all up to 100% in luminance, so maxCLL should be 10000 nits, but what about maxFALL? Obviously, since all frames are the same in this test pattern, it's enough to calculate the average light level for one frame only. But how to do it?

In case it comes up too high, I might need to reduce the size of the gradient, to avoid any dimming from the TV.Ok then i would just go with a generic value then for maxFALL, in general under 400 is typical. For your patterns maybe go low like 250. If you make patterns to 10,000 they will get rolled off or clipped. You will want to experiment with the results you obtain.

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[benwaggoner]

Ok then i would just go with a generic value then for maxFALL, in general under 400 is typical. For your patterns maybe go low like 250. If you make patterns to 10,000 they will get rolled off or clipped. You will want to experiment with the results you obtain.

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If you don't know the value, leave it at null, don't just stick in an arbitrary value. Some HDR tone mappers will use that metadata field, and bad things can happen if it is substantially different from the content.

The MaxFALL algorithm is kinda complex as it requires converting to nits in RGB space. Tools like ColorFront Transkoder get used for it in commercial HDR production.

[nautilus7]

Thanks for the advice.

What about compiling the source code of the metadata calculator in my first post? Can somebody do it please?