As PGS subs should be graded to the content already, probably best those are not touched for luminance (or at least on a separate config to the UI and self generated subs).
I.e. Kodi cannot just set a general max luminance across the whole OSD, it needs to treat PGS differently (or possibly boost PGS up first to be then be reduced as a whole on the OSD - but that is more a hack and likely have some corner cases.)
One way or another need all the elements balanced on the OSD.
Doing on the Kodi side means though it also needs a better way than looking at the content type to determine what to do, it needs to be informed the mode (SDR, HDR [HLG, DV, 10, 10+]) from the display.
Kodi to correctly balance all elements on the OSD.
Kodi to use knowledge on the displays mode, to apply the max luminance, not the content type.
interesting, appreciate you’ll have much more tech knowledge on this than me!
I have tried several Kodi platforms with PGS subs from HDR mkv files, and the only one that gets the brightness correct is the Vero V. Infuse on the ATV also does pretty well.
Don’t be fooled by apparent tech knowledge, I am a relative newcomer
Last November I was happily going through life with very little knowledge on all this.
I decided I wanted to convert my UHD BluRay and have them on a NAS mainly to save physical space.
I was absolutely amazed in 2023 that there was no device that appeared could play the resulting mkv correctly, but went with infuse on ATV and was going to call it a day at that (nice interface - but lacking audio height channels and p7 FEL)
But the lack of those things was stuck in the back of my mind, so went off to see if could do something about it - initially found the Monsoon Kodi build - and the craziness of the dev not sharing the source - started reverse engineering that (probably a fruitless task but a challenge) then CE came out with a p7 FEL semi working build so started following the progress of that.
By Feb that looked to have traction and so I got to grips with Ubuntu and GitHub, dusted off my C and C++ knowledge, and got the source compiling.
CE has some strong structures and not too complex to grapple with if you have a dev background.
The whole tv-led thing felt like a big mistake to me - no way Dolby would sign off on the SoC DV implementation if it just did it wrong and even stranger that actually a blank RPU was being sent to the display, so seemed likely a software problem - as it turned out to be.
Since then being thinking about things I would like and implementing and sharing - I hope some more can make it into the official builds.
Overall don’t underestimate what you can do if you put your mind to it, read up and learn if you have an interest, everyone is learning all the time
From various sites, it seems that PGS can have a DoVi metadata. I would guess that Kodi does not pass that information to the DoVi engine. There was one user on the OS MC forum who reported that Godfather had gold subtitles on an Oppo, but silver on the OS MC device.
Tried this build for the first time, big thumbs up and thanks for the work done on this. Getting excellent SDR conversion into my ancient Panny plasma. My DV mkv’s seem to be especially good, or is that my imagination? HDR10 sources also very good, occasionally found one (e.g. Thor) that is a touch dark, but overall the level of colour, contrast and sensitive handling of highlights within a very limited available brightness range of the display is really outstanding.
I’ve been trying out the SDR-to-DV conversion, and for much of my library the results are excellent, and I would not want to live without this now that I’ve seen it in action. With good HD sources the results can be outstanding. Fortunately, my Panny OLED has been happy with DV at all refresh rates that have been thrown at it. Sometimes, noise can be more obvious (e.g. opening shots of BBC Pride and Prejudice episode 1 - blu-ray source - the noise in the sky is much more obvious in DV), but overall this gives me another reason for the Ugoos to be indispensable, hope this makes it to the main build at some point.
I briefly tried HDR10 to DV but found this to be less successful, with noticeable loss of brightness without any obvious benefit, but others’ mileage may vary.
SDR to DV is definitely fun to watch; but I have a little different preference. I think HDR → DV is very good, but less so SDR → DV. VS10 is essentially a chroma upscaling engine. It can either upscale both gamut and bit depth, or just bit depth on SDR content.
On the SDR to DV conversion (both gamut and bit depth upscaling), the way it handles light reflections is a bit distracting (imo). Things like glints/gleams in eyes looks a bit too harsh; reflections look internally illuminated and over white rather than the softer source.
In this case, I think the conversion from rec709 to DV gamut is a bit too drastic and raw. On SDR content, I prefer only bit depth upscaling, but no chroma upscaling, setting VS10 to output into SDR10 instead. You get increased richness of color, but still keep the original rec709 gamut without transforming into the DV gamut.
On HDR to DV, the conversion of bt2020 gamut into DV is much less drastic, and I think handled more elegantly. Bt2020 is a much newer gamut, and the transition to DV is a smaller step. The DV output (both gamut and bit depth upscale) is very nice without the white saturation.
Of course there is no right answer here and the above is preference, but I find SDR10 output is the sweet spot for SDR content. Still fun to watch, but less saturated vs outputting to DV.
interesting feedback, will experiment further. I’ve certainly found some SDR content where conversion to DV gives a false-looking image with harsh highlights, but it tends to be SDR content that is not so good quality. I’ll check out SDR10 to see how it compares.
This is the problem with Zidoo’s VS10. When turned on, menus and GUI is almost searing to the eyes, uncomfortably bright. It’s actually a poor VS10 implementation since it pushes the TV harder for that extra brightness when browsing menus, just a complete waste of panel lifespan.
This would a be a super cool approach and preserves the intent of PGS subtitles.
I’ll have to play around with the Kodi OSD slider in the latest build, I don’t think it existed in my 0515 build yet.
One slider definitely less confusing to end user, hopefully amlogic method if the CE team chooses to incorporate that.
Not shared yet, but making code changes to allow autosys.sh to set the desired graphics level for the Menus (if not set there then will use 100) - so could set further down for more dark env or up for a bright room etc. Also think probably should set back to auto (0) when playing content and see how get on with that and using the Kodi side GUI slider, some VS10 and content combos I think could fall through and be too bright, but should be good for most.
Overall the whole thing needs reworking with these DV AMLogic devices in mind and should include looking at the subtitles handling in general for graphical subtitles.
I noticed that with CE on the Ugoos, the new HDR luminance setting for the GUI also has an impact on PGS subtitles.
If you change that setting from 40% to 100%, PGS subtitles look normal again.
I think this setting should only change the luminance for text-based (SRT) subtitles and not PGS subtitles, since they are usually already graded to match the DV/HDR content.
thanks, I find that even with the GUI slider at 100%, PGS subs via HDR playback are a little darker than they should be (with disc playback being reference). I’ve encountered this on several Kodi platforms, with the Vero V being an exception.
This is also why I let noise reduction enabled (I dont check the “disable noise reduction” checkbox), I think the loss of details it might induce is negligible especially with a projector that can’t be as sharp as a TV panel.
Not sure on the question, if you are asking what are my builds based on - then yes I typically will build on top of the CE GitHub repo head which is what the nightly builds are based on from my understanding.
