Odroid N2 tonemapping HDR->SDR

I have a C2 but I have content that is either HDR or 10bit x265 and the colors are washed out due to lack of color space conversion ( tonemapping ), same with 2K and 4K content.
I have an older Benq 1070 projector, will the N2 with CoreElec work for me?

Yes, the N2 is superior for tonemapping. Over at Kodi’s forum there is a thread with an overview of options where N2 is highly recommended (START HERE - Pick the Right Kodi Box) However, keep in mind that conversions are something one should avoid if possible as the experience is better when viewing in the same colour space :wink:

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The N2 can handle HDR with older TVs and projector (converts HDR to SDR), but colors/pictures are too dark (as reported often, search for HDR2SDR in the forum). Picture is not perfect as on a HDR-capable TV/projector.


Is a have owned the same old Benq W1070 and i still own the N2, the simple answer is: no. The tonemapping indeed does “something” like color space conversion (BT709 to BT2020), but colors are washed out, picture is (way) too dark, so no satisfying result for me.
I replaced the Benq 1070 with an HDR capable projector, the result is really brilliant. That is why I heavily recommend an HDR capable projector, there are even budget solutions like the bunch of HDR capable 1080p projectors from Optoma starting at around 700€.

Hi there,
I’m new one in the forum.
Looking at this interesting thread of discussion, I wonder the following:
I’m currently using a C2 with Kodi 18.2 / Libreelec 9.0.2 (still… Yes I know) on an old Panasonic Plasma TX-P50GT50, streaming from my NAS.
I’m also experiencing the washed out colors from HDR or 10bit x265 content…
We are now beg 2021, and I was wondering if the last Corelec release (Kodi 19 RC) may have (at least slightly) corrected the color/contrast issue from HDR to SDR conversion?
To know if buying a new N2+ would improve my current situation?
Many thanks

Welcome :slight_smile:

Firstly it costs you nothing if you put CoreELEC nightly on a spare SD Card and try it in your C2 before you invest in an upgrade, what I will say is after using CoreELEC on an older box for a couple of years that had hit its EOL point I did my research and the N2+ CoreELEC edition is one of the best purchases I have made in a while .

Edit the KKSB Case is also a good option for the N2+ I wrote a review on this thread

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The hardware on the N2 has quite a lot of flexibility for how the HDR->SDR conversion is handled, but there is no “correct”, optimal, or even good way to do this, since significant loss of dynamic range and color information is unavoidable, and the best choices may heavily depend on how your SDR display is configured, especially how high the backlight or equivalent setting is turned up and what brightness the SDR display is capable of.

It’s possible in the future there might be some configurability/different options for exactly how the mapping is done in CoreELEC, however:

TLDR: Most or even all consumer available HDR content have dedicated SDR masters also available. In almost all cases you’re better off watching this version if you have an SDR display. In this case the mastering has been done by a professional making the optimal and/or desired choices scene by scene, and is much better than any one-size-fits all conversion from HDR which can be done.

Sorry for the slow response. Did not find time to run some trials until today.
First of all, I really appreciate your feedbacks! Thank you!

Then my trials:

  1. Coreelec 9.2.5 (stable): honestly speaking, no visible change compared to Libreelec 9.0.2 (in terms of reading media quality/capacity). My 4k files are still playable and still washed-out…

  2. Coreelec 9.2 (nightly): again, no difference observable. I tested a 4K Remux video. Still washed-out.
    Naively, I thought Kodi 19 would add some HDR setting menu to switch HDR to SDR if detected (for eg), but I could not find it(?)

Based on this status, what would be the interest of purchasing a N2+ to replace my C2?

Many thanks.

The C2 is a GXBB(S905) device, so doesn’t have the ability to handle HDR to SDR, so no matter what OS you use HDR files will still have a faded/washed out look. Newer devices such as the N2+(which is a G12B(S922X) device) do have the ability to do HDR to SDR so will provide a relatively better picture. Though no matter what HDR to SDR is not ever going to be perfect, since you are still compressing the dynamic range when converting from HDR to SDR.

Brilliant! Thank you very much for this important details!
Ok then, let’s go for a N2+ then.
Question: 2 or 4Gb…? for Kodi (maybe Bartoca some day?)

I have one of both, the 2 GB one only runs CE and it does just fine. I bought the 4 GB N2+ because I also run emuELEC and other stuff on that particular box and figured I’d rather have the extra memory and not need it, than the other way around.

If you go for the EMMC module, do yourself a favour and get the adapter so that you can flash it easily.

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2GB is currently enough for CoreELEC, however if the price difference between the 2GB and 4GB model isn’t a big deal for you then I would suggest going with the 4GB model. It’s always better to have a bit more memory in case you need it in the future. Newer versions of software have a habit to want more memory, plus you may find that you may want to do other things with the device in the future then what you currently are planning, which may require more memory to do.


@cdu13a is right given the propensity of software to bloat and the price difference the 4gb version is the better buy.

I also echo @kshi about buying the EMMC adaptor if you go EMMC. Quite a few “problem” posts on the Hard Kernel forums tend to be centred on people who didn’t buy the adaptor and hit issues later.

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Sorry for coming back late.
I finally bought a N2+ 2Gb (4Gb is out of stock), with the standard case.
Installed CE Kodi 19 Nightly.
Works perfectly.
I now see an option SDR/HDR.
HDR files a pretty well converted to SDR.
I see a shift down in contrast & brightness (depending on moving encoding), but quite acceptable (et colors are back).
So it does make it, and it will until I buy a new 4K TV!

In parallel, I have been chased by some friends to try an Amazon Firestick 4K. Got one for trials.
But currently stuck with settings: I’m unable to access my NAS, via NFS. I see the NAS, I see my volumes, and then I can go further in the tree…

Anyway, I keep the N2+, and need to find a 2nd life for my C2.

These are my HDR -> SDR conversion tests:

@Oliver Welcome to the N2+ owners club understand the late reply you have been playing with your new toy as my partner puts it. Should be fine when you upgrade to 4K too.

I have the older model Amazon firestick its actually quite handy for some stuff here that Kodi doesn’t support, as for the NAS access, install and use the VLC application from the App Store which is what I do or you can go the trickier route and buy the PLEX app if your NAS has that functionality. Plex NAS compatibility list.

NAS access is well supported by amazon fire TV/stick

Very nice compare!
How did you catch the screenshots to get the picture-files for the compare?
I use a N2 (S922X) and beside the darfk picture there are als some small
artifacts (depending on the video)

Thanks, I used a DeckLink Mini Recorder 4K capture card with EDID Manager.

This is my 1080p -> 2160p upscaling test, if you are interested:

That’s pretty awesome. Looks like the Zidoo is doing the best job, followed by the shield AI, the rest of them are kinda meh, with S905X3 looking the worst :frowning:
Which SoC is the Zidoo based on? The Realtek if memory serves.