4k files playing as rec601

Hi. So after a bit of testing around the issues I am having with 4k files, and discussing with Lumagen, the issue appears to be that the Vero is sending the files in the wrong format, specifically rec601 as you can see in the image below (Format set as 444 SDR601 - this should be reading as HDR2020). It does appear to be outputting at 4k resolution however.

Comment from Lumagen below:

‘REC601 specifies the mathematical matrix the component video was created with for SD content….ie NTSC or PAL 480i or 576i’

Any thoughts?

If you enable 10-bit output, does it fix it?


Hi Sam. No, the 10 bit fix stops the 4k files from playing at all. Blank screen with no sound.

Can you clarify what you tried, and what your RadiancePro shows?

Tried the following in relation to 10bit. Screen was blank on any 4k files so I removed the code, so not sure what the radiance was showing:


That should be correct if your devices accept this signal.

What are you watching on?

Epson LS10500 projector. Vero goes into a Storm audio amp, out to lumagen, out to Epson

Have you tried directly as a test?

Some projectors do not handle 444,10-bit unfortunately.
We’ll add 12-bit output support in the future.

Recently, I added an option to activate BT2020 as follows:

echo do2020 > /sys/class/amhdmitx/amhdmitx0/debug

We’re a bit off from auto switching just yet.


Thanks - will have a look at direct. So I would need to do the above manually before playing a BT2020 file? Then I assume manually remove to play a Rec709 file?

I’m trying to decouple things so colour space and HDR are not tied together.

It may look OK for you to leave 2020 permanently on. I’d be curious how you find it.

Thanks - so I need to add BT2020 but not the 10bit code? Does BT2020 activate HDR also?

Test 10-bit directly first.

If no joy, then just use 2020 for now.
I’ll take a look at your machine’s manual.


To be fair it could be the storm amp causing the issue as much as the projector, as the lumagen is reporting the issue as an input (i.e. from the storm) and it sits before the projector.