4K HDR playback on 10.2Gbps HDMI chip projector?

Yes – it needs to be 12-bit.


With it set to 422 12bit it wont play 4K 29.96Hz content (some GoPro demo footage). Any ideas on that one? Need logs etc?

Nvidia shield can play these (3840x2160 29.96Hz 12 bit 422 bt.2020 SDR)

Yes – please post some logs.
When you say won’t play, what do you see?

Another HDMI cable may be worth checking.


Sorry, I should have been more specific; the content plays as my AVR is playing the sound but the projector is showing no signal once the content starts. Please find logs here https://paste.osmc.tv/afugiwajov

Skimming the log, is it trying to force it to twice the framerate (59.94) even thou the content is 29.97? If so then my HDMI chip cant handle 4K @ ~60 and alas no signal.

Yes – this is the problem.
You can override FPS, but it’s not recommended.

See 25Hz content playing back at 50Hz - #22 by RichieB for an example

YCbCr 4:2:2 pixel encoding is by HDMI specification always 12-bit. If fewer than 12 bits are used, then the valid bits are zero padded below the LSB.

The Shield can do it, but you must knock the GUI into the right mode before watching the movie. They never fixed the colourspace switch, just framerate. This leaves navigating your menus very clunky and when you go back to a regular 1080p source it’s comes out as full RGB making the picture super black and contrasty and still at 24hz.

You must switch back for 1080p to avoid this.

The very real issue is most projectors, even if you can stomach high lamp mode, don’t have enuff bobbins to display HDR properly until you start getting into £30k+ units, you do get a little bump in colour tho which is nice especially on a good projector, so while not great or close to HDR it is worth it still.

Hopefully the fix will just be what you play is what you get. i’m not aware right now of any media player that will do colourspace and resolution and HD audio switching properly even with 18gbps chipsets in the chain.

I will have to check when I get home but I’m almost sure on my shield its set to 1080p 59.94Hz (or 60Hz) 422 12bit and it both resolution and frame rate switches. Aware of colour space switching issues, hence bought the Vero.

So regards 29.97 content, is it that it should be doubled eg thats the norm and in the case of the Shield its not doing the norm and playing it as 29.97 and hence my projector can play it.

If this needs a separate thread then please split it.

Doubling the frame rate is not the norm. The 4K HDMI specs allow those framerate as well as the double of them. But Kodi always doubles framerate e.g. from 25 to 50 fps. Which would be an issue for users with equipment that can’t do 4K @ 50/60p…

Thing is Kodi on Shield is not doubling it whereas Kodi on Vero is!

Refresh rate is set to on stop/start for both

Vero is reading the EDID from only your AVR and that is reporting the 4k50Hz and 4k60Hz modes.

====================== EDID =================== wE0go885
Rx Brand Name: DON
Rx Product Name: DENON-AVR
Manufacture Week: 0
Manufacture Year: 2016

I don’t know too much about EDID but on my setup vero reports the EDID of my TV, filtered by the capabilities of my AVR. Is your beamer connected through the AVR or on a splitter, perhaps? You could try this to force it:

echo 2160p30hz | sudo tee /sys/class/amhdmitx/amhdmitx0/disp_mode

It says this in the version of HDMI2.0 you can get from the refs in the Wikipedia page:

I don’t know if it’s up to date (probably not) but suggests you can use 10-bit with any fps and pixel format. However, the orange chart above does come from the HDMI website so must be right, I guess.

Indeed. So not a problem in the real world.

Beamer is connected directly to AVR

From the log I see Display Cap also showing 2160p30hz among others

 ====================== Display Cap =================== g0gjk991
1 Like

Yes, but if kodi is converting the stream to 60Hz (don’t know why, but it seems to) it will choose a 60Hz mode to output the stream to HDMI.

That’s why I suggest to force 30Hz with the above incantation.

That table is a summary of tables 2 & 5 from BT.2020. The actual pixel encoding structure for 4:2:2 hasn’t changed from as originally defined in HDMI 1.0

Well, the official table from the HDMI Licensing Administration is this one:


It’s pretty clear about the combinations allowed.

Sorry for the delay in replying, I had hit the daily post limit as I’m a new member!

that didn’t work unfortunately but creating an advancedsettings.xml with the following did…

1 Like

I’m building a nice wee HDR collection in prep for this when my new vero4k+ arrives and a fix is applied.