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HLG Thumbnails with wrong colors

Posted: 30 Mar 2023, 09:41
by Iwwazwersch
Hello,

I have a problem with videos recorded with an iPhone 12 Pro.

The videos are HEVC (H.265) (hvc1)
The videos are in the color space: ITU-R BT.2020 with Hybrid Log Gamma

The generated thumbnails have incorrect colors.

If I convert the videos to H.264 (avc1) with VLC, the color space is retained according to the codec, but Hybrid Log Gamma is removed.
The thumbnails are now generated correctly.

I suspect the problem is HLG (Hybrid Log Gamma).

Unfortunately I can't provide any sample files at the moment.

Re: HLG Thumbnails with wrong colors

Posted: 30 Mar 2023, 14:12
by admin
Hello,

Thank you for the request.

Which version of VTM did you use?
Also I need to know what exactly is wrong. Are colors are totally wrong, or we are talking about light difference?

BTW I have found a sample - the first one on the page:
https://www.demolandia.net/4k-video-tes ... age-1.html
Please confirm.

Re: HLG Thumbnails with wrong colors

Posted: 05 Apr 2023, 10:17
by Iwwazwersch
Hi,

i used V.23.0.0.0

I think Both of Them Colors and Lightning.

Re: HLG Thumbnails with wrong colors

Posted: 05 Apr 2023, 16:12
by admin
Please check the result below (created with VTM 24.0.0.0):
test3.jpg
test3.jpg (209.43 KiB) Viewed 7716 times

Re: HLG Thumbnails with wrong colors

Posted: 06 Apr 2023, 14:39
by Iwwazwersch
Hi,

same Problem with 24.0.0.0.

Screenshots attached