Req Hdr subtitles
#16
Not that we know so if any developer is willing he/she can jump in and make the needed changes
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#17
(2017-12-12, 21:17)wesk05 Wrote: PQ EOTF has absolute luminance which means RGB/YCbCr code values are fixed. "64" would be 0 nits and "940" would be 10,000 nits. "512" is 100 nits. If you want the subtitles to be dimmer, then you have to use a color that has code values around 500 or even lower.
 What wesk05 says.  HDR10 (which uses PQ) means that video levels (which are 10-bit usually for HEVC HDR10 content) map to specific light levels, and you can't use SDR levels unchanged for HDR output.  

I suspect white subtitles in SDR content are close to peak white - which is 235 in 8-bit or 940 in 10-bit.  As wesk05 has said - 940 in 10-bit HDR10 (which uses PQ) would be 10,000 nits. Most TVs don't reach 1,000 nits - and that's very bright, so you can see why subtitles will appear uncomfortably bright if you just use SDR video signal values in an HDR PQ EOTF.  

In theory, correctly graded HDR material should really only be using >100nits for spectral highlights (though this is often not the case), which means that 100 nits should equate to SDR peak white.

As a result subtitles that are rendered peak white 235 8-bit/940 10-bit over SDR content (where peak white - according to standards - should be 100 nits), should probably be rendered at 128 8-bit/512 10-bit in PQ HDR10 output to set the subtitles at the same light level of 100 nits in PQ HDR10?  

This would be a good starting point?  (Halving RGB levels when rendering subtitles over HDR10 PQ content output in HDR may make sense as a quick fix?)
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#18
So is still no solution for this ?
The subtitles are way yo bright on my LG OLED in HDR movies ! Setting the subtitle color to grey doesn't make any difference, initially I thought that there is a problem and the color is not applied, but the rest of the colors (yellow, pink, etc..) work. So it seems that grey is working also but on HDR is as bright as white...  Sad
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#19
(2018-10-24, 23:23)Martijn Wrote: Not that we know so if any developer is willing he/she can jump in and make the needed changes

Still a big problem. Subs are essentially unusable when watching a movie on a dark room. I really wish this was getting improved.
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#20
A dark grey already been added in v19 development Nightlies see 2871524 (post)
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#21
Great! At last!

Could it be backported to Kodi 18.x, please?

It's a very long time until Kodi 19 will be launched...

Thanks!
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#22
(2019-12-04, 10:45)jjd-uk Wrote: A dark grey already been added in v19 development Nightlies see 2871524 (post)

Ah thanks, that's good news! I wonder if that will be sufficient though, without changing the actual brightness value in HDR. But a step in the right direction in any case! Smile
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