1080p, 4:4:4, 8bit not an option?

Hi.

Just received my Vero 4K+.

Its outputting SDR 1080p files as 10bit 4:4:4 and not 8bit 4:4:4 which is also part of the HDMI 2.0 standard. Wouldnt this introduce the same issues as outputting 10bit HDR files as 12bit?

Is there any way i can get it to output 1080p, 24hz, 4:4:4, 8bit for SDR movies like my AppleTV used to?

Why? What issues?

Hi @simenh1

This shouldn’t provide any issues. It’s possible to force 8-bit output manually, but we don’t recommend doing so.

Sam

Ok thank you. That’s all i wanted to hear :slight_smile:

2 Likes

I just updated from the last Kodi 17.x OSMC version to the new October update. Before, only HDR-videos played at 10bit, everything else was 8bit. Now it’s always 10bit. I don’t remember if I had a special setting on the Vero 4k in some file for it do to that but what do I need to do to get that behavior back?
I remember back then the reason I didn’t want 10bit on my SDR is because my TV was calibrated with an 8bit signal and it receiving a 10bit signal was not quite the same.

I can’t think of a reason why a calibration done with 8-bit source should be different from one done from the same source with two bits (probably zeroed) added. AFAIK you can’t manually switch a display to accept one or the other to do different calibrations for different bit-depths.

The way you were doing it was probably using Kodi to switch as soon as it sensed a BT2020 EOTF. This is less than ideal since there is 10-bit video which is not HDR. Then we had problems trying to switch 8 to 10 bits on the fly, hence ended up just sending 10 bits if a display supported it. That was done over a year ago ie when we were still on Kodi 17. I can’t recall any complaints about changing colours.

Having said that, if you are getting other issues (eg loss of picture) let us know and remind us what equipment you have.

Are you saying pure white in 10bit is represented as a triplet of 0b0011111111 instead of 0b1111111111?

No. 0b1110101100

You’re right, I forgot about the limited color range. I’ll keep an eye on the PQ then, maybe I’m just remembering it wrong (it’s been almost a year).

If you are really worried about it and doing your own calibration, you could

echo 4448bitnow | sudo tee /sys/class/amhdmitx/amhdmitx0/attr

and let us know if it actually makes a difference.