Vero 4K KODI not passing (some) HDR metadata


#1

Hello,

after checking there are no updates available, I hooked my Vero 4K to a HD Fury Vertex connected to a Sony 4K TV.

I then played some 4K HDR content on Vero 4K, and it looks to me like Vero 4K (or Kodi?) strips some of the HDR metadata. It outputs most metadata, such as max and min luminance, just fine, but MaxCLL and MaxFALL are set to zero, i.e. not passed from source to display.


HDR/tone mapping
#2

What 4K HDR content did you play?
Check dmesg | grep hdr for a bit more detail.

MaxCLL / MaxFALL would come from source; they are not calculated on the fly. I believe versions of MediaInfo from November or later support reporting this information.

Sam


#3

I played a variety of MKVs, remuxed from UHD Blu-rays, and also UHD Blu-ray m2ts files. I checked them all with MediaInfo first to make sure they have all the usual HDR metadata, including MaxCLL and MaxFALL.

I can see the Infoframe values Vero outputs, and MaxCLL and MaxFALL are both a string of zeroes instead of their proper values. Other metadata, such as PQ and color primaries information, are passed intact from Vero to TV.

I tested another media player in the same set-up, using the same files. It passes all metadata, MaxCLL and MaxFALL with proper values included, from source to TV.


#4

Do you have one, small, potentially Dropboxable file which reproduces this issue?

Sam


#5

I’ll make one.


#6

Okay, here we go. Download links first:

mkv (49MB) - https://mega.nz/#!4RoWSJ5I!u8TnuhYdjmIBfQ7VBwZ5EoiRVZKlyOx3LHkxPk4_bhI
m2ts (6MB) - https://mega.nz/#!5VJSiIDB!wIaksQvtfh0BruOXgagICE7JI4V8ciHGmSz1Y-kVIqs

I checked both files on another media player; it passed all metadata to the TV. I also checked both files with MediaInfo, to make sure metadata was intact.


#7

Can I ask what the other mediaplayer was so as I can test


#8

The one that passed metadata? It’s a HiMedia Q10 Pro. I also discovered that Egreat A10 does not pass MaxFALL/CLL.


#9

Did you note a visual difference?

MaxFALL/MaxCLL is needed for scenes change; i.e. DV / HDR10, but we do not implement HDR10 or DV at this time.

Sam


#10

The Zidoo doesn’t pass this info either and neither does my samsung UHD player, but the Oppo does. I’m guessing its not actually needed for HDR playback and more just for info?


#11

Indeed.


#12

It’s not needed for scene change. It’s static for the whole stream ie. movie.


#13

It’s used as a variant for HDR10/DV.
I haven’t yet seen it necessary for static content. Can you let me know where you’ve seen this is the case?

There are of course fall backs.

Some improvements are being made re. HDR/HDR10, but nothing public to be discussed at this time.

Sam


#14

MaxFALL/CLL are part of HDR metadata, present on practically all UHD Blu-ray HDR discs and UHD HDR streams, and essential information for tone mapping done by the display. HDR10 metadata is static, i.e. it doesn’t change during the feature, unlike dynamic metadata in Dolby Vision and HDR10+.


#15

I did not check for visual difference; it’s almost impossible to eyeball with only one TV.

MaxFALL/CLL are not for scene change since HDR10 is static metadata, not dynamic. They are needed for tone mapping when display is incapable of producing the brightness levels present in source.


#16

The metadata for HDR10 is static, so the MaxFALL/MaxCLL are a static metadata.
That would change for HDR10+ (and DV) but that’s not what the question was about.
It shouldn’t be that neccesary for most content as the TVs default tonemapping should be adequate for most content. But if say the Nits specified in MaxFALL/CLL is specified as is say 700nits, and you have a a TV that does 800Nits. Then the metadata would telle the TV that no tonemapping is required and you should in theory get more details in the highlights. That is if the TV does in fact incorporate proper support for MaxFALL/MaxCLL (I don’t think most do, but that is a gut feeling)


#17

Is this still on the radar to be addressed? With a number of the Vero4k users connecting up to projectors, it does seem we are missing out on potential tone mapping if MaxFALL/CLL are not passed. In an overview of the JVC X5900 there is a quote that says:

“JVC engineers have done a fantastic job designing their tone mapping curve that responds differently to different Max CLL or Max FALL data. In fact, this is the first display - either TV or projector - that we’ve seen show this information in the user menu.”

Personally for me on my X5500 at the moment 4k HDR Remuxes from the Vero 4k is a bit of let down compared to standard 1080p BluRay Remuxes. The later just look more punchy and detailed. This is even with the current test release that tweaks the NR setting. And i’m using custom gamma curves on a calibrated PJ.


#18

We will keep making improvements.
There are more HDR improvements scheduled for the next update

Sam


#19

Just wondering if there are any updates with getting the full HDR metadata passed? The new JVC projectors are going to adjust HDR mode based on this metadata so would be good to have it working.


#20

Yes — see the HDR too dark thread

Next update should have some improvements

Sam