444 10bit output from vero 4k

Just wanted to report that the test build has resolved the flickering at 2160p 24hz in my test clip. :+1:

Hopefully the same will be true for others that are testing as well - certainly looks like this is well on the way to getting sorted.

Was just about to post, the flickering is gone in all refresh rates, however there’s dithering issues instead, showing visible banding. Sam thinks this should be solvable, so we’re definitely making progress!

Edit: https://www.dropbox.com/s/uym96d51t6f3ct3/HDR_Flicker_10bit24fps.mp4?dl=0 here’s a test video i made which clearly shows the hdr flickering in 24hz. Its no longer flickering but instead banding.

This thread has been derailed by miles… nothing to do with 10/12bit anymore :slightly_frowning_face:

Sorry thought this was the hdr flicker thread, they kinda merged.

… if there is banding, it might be related to the output bit depth.

Same problem here (same projector).

Out of interest, would this work? echo ‘422,12bit’ >/sys/class/amhdmitx/amhdmitx0/attr

As it’d still fall under the 10gbps bandwidth limitation of the projector?

Nope, just a green screen :wink:

If you change resolution to 2160p60 i believe it works, but that doesn’t help much

Yeah sorry that was at least partly my fault… :pensive:

Having said that, HDR 4k playback is obviously getting attention with fixes so hopefully it’s of interest here too.


I’m assuming the green screen at 4.2.2 10 or 12bit is due to this bug? Auto frame rate switching & dynamic range matching - 4K (HDR10) capable Hardware

Is that something you’re able to fix yourself or does it run deeper than that?

EDIT: Reading further in that thread it looks like they’ve fixed it, I’m sure wrxtasy would be happy to pass on the fix if you shot him a message :+1:t2: Or perhaps it’s simply a case of using the newest Amlogic kernel which has the fix in it…

This has already been covered a few posts above. See 444 10bit output from vero 4k - #117 by Theetjuh

Fix comes from AMLogic but then HDR will not work. We are working on a more pragmatic solution :slight_smile:


Oops, sorry mate, totally missed that

I’ve installed Ferbruray update and HDR flickering issue changed to banding and it is much worse now that i’m considering to roll-back.

Is there a solution for this banding issue ?

Right now, no. You could rollback or watch HDR Banding issue - #11 by MikeDelta for solutions or testing builds being announced by Sam. It’s definitely being worked on.

Any progress?

See other banding threads.

I went through the banding thread,

I couldnt see exactly if it answers my question about being able to play and choose
4:2:2 12bit since this is subsampling that should be transmitted with 9 Ghz?

can you point me to something clearly as this is what I am after?

thank you

hi Sam, how is this progressing? likely to get into next months update?

Are you referring to HDR auto switching?
There’s a test thread. It still needs some work.


Thanks , I will have a look