[TESTING] Vero V: IPT colour space conversion

I’m not too au fait with the technicalities, but just wanted to report that this works perfectly for me on previously messed up files.

Vero V to LG OLED65B9

The Vero 4K + is not supported and installing the above would cause problems on your device.

Do you mean Vero V?

Oops, sorry. Its a VeroV.
I’ll edit my original post

Working well on my V with a Denon AVR and a Samsung QLED … thank you for that!

Thanks for clarifying.

Don’t worry, you don’t need to know! I just find there’s a lot of misinformation around on the forums and even in the early ‘this is what you need to know about Dolby Vision’ articles that have never been corrected.

Of course, I may be wrong.

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This is working well for me too, but the image (in HDR) is a lot darker than the HDR equivalent of the same episode or movie (tested a couple of files). Is there any EOTF tone mapping going on as well, or am I doing something wrong?

Probably not. Brightness seems to vary between TVs. It’s darker on my Philips OLED than on my Panasonic LED. I for one don’t know why. What make/model is your display?

If you force SDR output with settings->player->videos->HDR processing you should be able to adjust the brightness and contrast from the OSD video menu but IIRC we disabled brightness and contrast when outputting HDR. If we can get some more feedback from users then we might understand why there are differences and make adjustments to suit.

I experienced similar on an LG OLED55CX TV. The colors are decent, but the brightness is significantly lower compared to other HDR content.

I tried the suggested option, but forcing the SDR output only made it worse, it became even darker.

So, downloaded a small number of Dolby Vision files including this one from the Kodi wiki samples -
https://kodi.wiki/view/Samples#4K_(UltraHD)_Formats

Specifically item 16 in the list of 4K(UltraHD) Formats. -
Dolby Vision 10-bit HEVC 23.976fps (filename - ‘LG Demo DolbyVision Trailer.mkv’)

So I played this file, before making the update, and it rendered OK on my LG TV which detected HDR.

I then updated my Vero-V with the tone mapping kernel + osmcapp, and rebooted.

I played this file again, and now the TV renders a completely blank/black screen (except telling me its rendering an HDR stream).

It’s regressed !

Here’s the media info for the video stream:

For the other DV files I tried, which originally rendered in magenta/green, the tone mapping update seemed to work well, except perhaps for some artefacts around the edges of the red wooden blocks in the ‘Blocks’ MP4 here -

Try playing Dolby Vision 5 content. That’s the purpose this testing. The file you tried playing has a fallback layer, so we don’t need to do any post processing on this file.

Will check for the regression shortly, good to know :slight_smile:

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Thanks for the reply!
I have a Sony A95K. Could it have to do with the 10.000 nits maximum luminance metadata for Dolby Vision? To me the image sort of looks like the tv compresses a 10.000 nits image to whatever the tv can handle. Maybe I should try to find a 10.000 nits hdr test file to see how the tv reacts to that.

Yeah, tried this Profile 5 file and it looked splendid on my setup (media info below)

Dolby Vision Mystery Box (Profile 5)

Also noticed (with this video file and others) that the video thumbnails are coming up magenta/green, rather than the tone mapped colours …

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Great!

Yes. Someone would have to do some serious ffmpeg-fu to correct that. And it would have to await ffmpeg 6 I believe. But at least you can see immediately it’s Profile 5 :stuck_out_tongue:

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AFAICT DV Profile 5 files are always mastered at 4000nits.

Yes, I’ve seen that. Also in the ‘Art of Essence’ clip.

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Thanks for testing. It looks like we may have to wind up the brightness generally.

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Are there any visual compromises involved with this new method compared to playing the original DV files?
i.e does the “scene by scene” metadata survive the conversion?

I guess inevitably as OSMC is not licenced for DV so has no access to the secret sauce. You can compare the results against your TV’s internal player.