Vero 4K KODI not passing (some) HDR metadata

Any chance the April update includes any HDR metadata changes? :slight_smile:

No, sorry. Kodi is not handling it yet.

We are still working on the next kernel bump.

Sam

1 Like

I know these kinds of questions are annoying, but do you have a general timeline for the next kernel bump?

I know this isn’t the answer you want but here comes:

When it’s ready!

Steering the conversation away from sassy axioms, what is the practical impact of not passing MaxFALL/CLL metadata? I’ve noticed that oftentimes HDR content from OSMC appears dim or underexposed, especially in midtones. The issue is not present when watching the same content via a different source.

Is that consistent with absent MaxFALL/CLL metadata?

Not all titles feature MaxFALL / MaxCLL metadata, so it can vary by title.

There is no firm ETA for this at this point.

Sam

Varying by title is very consistent with the issue I’m seeing. Some titles appear dim, some don’t.

If a piece of content features MaxFALL / MaxCLL metadata and OSMC isn’t passing that metadata, would that typically make it appear “dimmer?” I’m using that as a catch all phrase to describe the outcome of incorrect or truncated tone mapping.

There’s a spreadsheet somewhere with a list of titles and if they pass through meta data.

It shouldn’t cause dimness; but passthrough of all metadata is something that will happen sooner rather than later.

Sam

I don’t think so. I think the differences between how studios and directors are making use of the bigger gamut/dynamic range are greater than the difference between material with MaxFALL/CLL and without.

Has anybody done a study on whether this metadata makes any difference to the picture quality?
I’ve just run mediainfo on a random 8 UHD files in my collection and only 2 had the MaxFALL/CLL info and a quick google seems to suggest it is not mandatory information for decoding, only during mastering.

I don’t design TVs, but if I did, what would I do with MaxFALL? If it was higher than my panel could manage, would I dim the whole movie just so those few seconds would play ‘in proportion’? No - I would limit the overall level just for those few seconds, attempting to make it as unobtrusive as possible. Just the same as I would do for a movie without MaxFALL.

As for MaxCLL, I guess if it was a lot less than the maximum brightness of the mastering display I could think about adjusting the tonecurves to better suit the range of my display. But I wouldn’t mess with the mid-tones or darks.

Bottom line: I doubt very much if you would see any difference.

From what I’ve read most consumer displays take no notice of the metadata anyway, other than the new JVC projector’s Auto Tone Mapping feature.
As it seems a lot of UHD material has the metadata either missing or “best guessed” based on the properties of the equipment used during the HDR grading process I wonder how useful that feature actually is?

There is some interesting (depending on your point of view :smile: ) info on MaxFALL/CLL here:
https://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=118846&PageNum=2
https://www.mysterybox.us/blog/2016/10/19/hdr-video-part-3-hdr-video-terms-explained
https://www.mysterybox.us/blog/2016/10/27/hdr-video-part-5-grading-mastering-and-delivering-hdr

That Mysterybox series is a good read. Strips away the BS.

This is why I am personally so interested in the HDR metadata being passed by OSMC. I am running a JVC RS2000. The Auto Tone Mapping feature makes a significant difference when it is passed a source that has proper metadata, since projectors are not generally able to display the full range of HDR brightness. Otherwise the user needs to tweak the gamma levels themselves per movie. I have had excellent results with the Auto Tone Mapping on sources that provide proper metadata.

For the record, of course there are many UHD titles that don’t provide any metadata, and there’s nothing that can be done there, but the ones that do should be supported.

@sam_nazarko Any updates to HDR metadata in the recent releases?

Yes I’m hoping this will be added soon.

It will come with the 4.9 kernel.

Will this be the next release (August update)? Or is that still unclear and depending on testing?

Not necessarily.

It will be released when it is ready.

4 Likes