[RockDawg]

I want to buy a new HDR 4K TV and I use Kodi on nVidia Shield exclusively for my video playback.  All locally stored content.  My question is if I start storing HDR UHD rips on my server will Kodi (on the Shield) play them back without issue and without having to change my TV or Kodi settings?  Will it be automatic?  I'm just wondering how it would work and if I will need to change any settings when switching between Blu-Ray rips and UHD rips.

[wrxtasy]

I want to buy a new HDR 4K TV and I use Kodi on nVidia Shield exclusively for my video playback.  All locally stored content.  My question is if I start storing HDR UHD rips on my server will Kodi (on the Shield) play them back without issue and without having to change my TV or Kodi settings?

You will be manually changing settings for mixed 1080p / 4K HDR video playback even if using auto resolution switching.
Read THIS post and follow the links:

Will it be automatic? 

Automatic refresh and resolution switching but then you will have colorspace problems, unless you manually fiddle with Android settings.

Its why a bunch of early 4K HDR adopters are getting AMLogic S905X or S912 boxes and running OSMC or LibreELEC Kodi on them. Where everything is automatic once setup.

See this thread:
Nvidia Shield vs Minix U9 -h vs cheap android boxes

And if you are a real demanding Kodi 1080p / 4K HDR user this Shield upscaling thread should definitely be read as well, particularly due to the 4K HDR colorspace issues:

Disable upscaling in Nvidia Shield? (4K/UHD)

Basically what we are saying is there are better non Android platforms for Kodi use than the NVIDIA Shield, which is a great all rounder, consumer grade media player platform until you start become a real demanding 1080p / 4K HDR Kodi user and want everything to work properly without continually fiddling with Android settings.

Other 4K HDR options are the Himedia Q10 Pro and the Zidoo X9S - but I believe they have no 1080p / 4K resolution switching. Its manual settings for mixed 1080p / 4K HDR optimal picture outputs again. I happy to be corrected if this is wrong.
Both do not even run Kodi for 4K HDR video playback but use it as a frontend for an external media player.

[rgupta1969]

I am using a Intel NUC kaby lake and a Sony native 4k projector
I have 4K UHD HDR bluray rips

Kodi cannot play HDR content properly

i tried using powerdvd17 with a significant better result. Still early days with powerDVD

I hope to see a roadmap with HDR on kodi

[feerlessleadr]

That statement is not entirely correct

kodi plays 4k HDR content just fine on my Minix U9H via librelec on my LG E6 OLED.

[mozomo]

kodi plays 4k HDR content just fine on my Minix U9H via librelec on my LG E6 OLED.

I second that. 4k HDR works perfectly with the U9 (S912), as long as you do not use subtitles. With subtitles you'll have dropped frames. You can find more abou this subject in the Libreelec forum.
The best solution for 4k HDR I have found yet is a box with a S905x like the Vero4k. But as everything is in flux that may change any day and tomorrow there could be a better solution...

[nickr]

I want to buy a new HDR 4K TV and I use Kodi on nVidia Shield exclusively for my video playback.  All locally stored content.  My question is if I start storing HDR UHD rips on my server will Kodi (on the Shield) play them back without issue and without having to change my TV or Kodi settings?

You will be manually changing settings for mixed 1080p / 4K HDR video playback even if using auto resolution switching.
Read THIS post and follow the links:

Will it be automatic? 

Automatic refresh and resolution switching but then you will have colorspace problems, unless you manually fiddle with Android settings.

Its why a bunch of early 4K HDR adopters are getting AMLogic S905X or S912 boxes and running OSMC or LibreELEC Kodi on them. Where everything is automatic once setup.

See this thread:
Nvidia Shield vs Minix U9 -h vs cheap android boxes

And if you are a real demanding Kodi 1080p / 4K HDR user this Shield upscaling thread should definitely be read as well, particularly due to the 4K HDR colorspace issues:

Disable upscaling in Nvidia Shield? (4K/UHD)

Basically what we are saying is there are better non Android platforms for Kodi use than the NVIDIA Shield, which is a great all rounder, consumer grade media player platform until you start become a real demanding 1080p / 4K HDR Kodi user and want everything to work properly without continually fiddling with Android settings.

Other 4K HDR options are the Himedia Q10 Pro and the Zidoo X9S - but I believe they have no 1080p / 4K resolution switching. Its manual settings for mixed 1080p / 4K HDR optimal picture outputs again. I happy to be corrected if this is wrong.
Both do not even run Kodi for 4K HDR video playback but use it as a frontend for an external media player. 

Is it easy/possible to run osmc on your average s905X box? I didn't know that!

[fritsch]

HDR works on all those boxes that don't use kodi rendering path. Though - I am quite amused how AMLogic should properly work for HDR rendering - their framebuffer is RGB after all. Standard Androids do it with Mediacodec Surface, which is a blackbox and what it does is totall hidden to kodi. You see those nice effects when playing HDR content and have subtitels / kodi menu on top.


For the kodi roadmap:
- We can properly decode HDR, we transfer it using a BT2020 matrix to RGB. What we are missing is applying the correct Transfer function. That means when doing 8 bit BT709 output (For the bikeshedder, you know what I mean ...), the original assumed EOTF needs to be undone (not a linear operation) and it needs to be properly transformed if you output on non HDR whatever screens.
- This will end up the same as PCM vs. Passthrough. In HDR "Passthrough mode" - you see that with Android Mediacodec Surface, all the HDR bits metadata is hidden to us, it's done in the driver / Framework - vendor specific. We are looking forward to support the first approach in kodi to have decent looking pictures in our rendering path, depending on available output.

If someone wants to really understand the issues, please read: https://www.google.de/url?sa=t&rct=j&q=&...zVEaacUXfd
For what Android does (why it works and why kodi has zero influence that it works), see: https://source.android.com/devices/tech/display/hdr and especially the vendor part here: https://source.android.com/devices/tech/...peline.png by scrolling down

PS: It does not really matter to get all the details above 100% correct. As bike-shedding won't help to solve that issue. For platforms like Linux, where 30 bit visuals are currently work in progress (see mesa-dev ml), but where you don't have any further infrastructure available to tell the Output device the HDR metadata, OpenGL renders RGB don't forget that, the first approach: doing it properly in software and making sure the chain we use is as "lossless" as possible is the way to go for now.

[swagner74]

double post

[swagner74]

Well, thanks for this. Very interesting. I (hopefully) have a better understanding of where KODI stands regarding HDR.

Not sure though I fully understand all the details so I'll take the plunge and try to summarize in layman's terms (so that someone can correct me if I'm wrong. Thx in advance).

In the end, KODI is very likely to have a "HDR Passthrough mode":
- "HDR Passthrough mode" ON : The content of a 10bits HDR HEVC encoded file (including metadata) is passed through to the HDR compatible TV/monitor which will take care of all the processing and display the video (thus in a way similar to android mediacodec surface in the sense that KODI doesn't process the stream; but today linux lacks a way to actually pass the metadata)
- "HDR Passthrough mode" OFF : The content of a 10bits HDR HEVC encoded file (including metadata) is processed by KODI (and possibly other software layers?) in the best possible "lossless way", so the resulting data can match the capabilities of the display device

[wesk05]

For platforms like Linux, where 30 bit visuals are currently work in progress (see mesa-dev ml), but where you don't have any further infrastructure available to tell the Output device the HDR metadata, OpenGL renders RGB don't forget that, the first approach: doing it properly in software and making sure the chain we use is as "lossless" as possible is the way to go for now.

The first approach will be good only for HDR to SDR conversion. If you don't pass the ST.2084 transfer function flag to the display, it is highly unlikely to get more than 400nits out of the display when it is in SDR (BT.1886) mode. Almost all displays available in the market are designed to have different peak luminance in HDR and SDR modes.

[rgupta1969]

tHDR works on all those boxes that don't use kodi rendering path. Though - I am quite amused how AMLogic should properly work for HDR rendering - their framebuffer is RGB after all. Standard Androids do it with Mediacodec Surface, which is a blackbox and what it does is totall hidden to kodi. You see those nice effects when playing HDR content and have subtitels / kodi menu on top.


For the kodi roadmap:
- We can properly decode HDR, we transfer it using a BT2020 matrix to RGB. What we are missing is applying the correct Transfer function. That means when doing 8 bit BT709 output (For the bikeshedder, you know what I mean ...), the original assumed EOTF needs to be undone (not a linear operation) and it needs to be properly transformed if you output on non HDR whatever screens.
- This will end up the same as PCM vs. Passthrough. In HDR "Passthrough mode" - you see that with Android Mediacodec Surface, all the HDR bits metadata is hidden to us, it's done in the driver / Framework - vendor specific. We are looking forward to support the first approach in kodi to have decent looking pictures in our rendering path, depending on available output.

If someone wants to really understand the issues, please read: https://www.google.de/url?sa=t&rct=j&q=&...zVEaacUXfd
For what Android does (why it works and why kodi has zero influence that it works), see: https://source.android.com/devices/tech/display/hdr and especially the vendor part here: https://source.android.com/devices/tech/...peline.png by scrolling down

PS: It does not really matter to get all the details above 100% correct. As bike-shedding won't help to solve that issue. For platforms like Linux, where 30 bit visuals are currently work in progress (see mesa-dev ml), but where you don't have any further infrastructure available to tell the Output device the HDR metadata, OpenGL renders RGB don't forget that, the first approach: doing it properly in software and making sure the chain we use is as "lossless" as possible is the way to go for now.

 Thanks for the detailed reply. what is the road map for HDR decoding in windows platform

[fritsch]

For platforms like Linux, where 30 bit visuals are currently work in progress (see mesa-dev ml), but where you don't have any further infrastructure available to tell the Output device the HDR metadata, OpenGL renders RGB don't forget that, the first approach: doing it properly in software and making sure the chain we use is as "lossless" as possible is the way to go for now.

The first approach will be good only for HDR to SDR conversion. If you don't pass the ST.2084 transfer function flag to the display, it is highly unlikely to get more than 400nits out of the display when it is in SDR (BT.1886) mode. Almost all displays available in the market are designed to have different peak luminance in HDR and SDR modes. 

 Yes: A simple setting, where user can "shift up" and "shift down" until he likes what he sees would be fine for this SW approach as a first step. Basically: We have to work with the limited things we have available since kodi was "invented". Only relying on proprietary stuff like Mediacodec and others won't bring us any further. We still have a whole lot of users that don't have any HDR display or watch HDR content on their laptops and everywhere else.

That being said: We need help for both approaches.

[ashlar]

This whole 4K/HDR/Atmos/Dolby Vision thing seems born just to irritate us HTPC (and similar) users...

[nickr]

Sells TVs and AVRs though!