October update issue


At the moment, we are not seeing 4k@50/60 advertised, but seems you are expecting at least one screen to play that. What happens if you set compatibility to Sink?


Just to add - putting the video output into full bypass, lets it report properly as YUV 8bit

Currently you have to do this for Dolby Vision - not that any beamers have that option, but you loose OSD.

Mine is set to ‘none’ here’s the blurb on it:

Per output you can specify what video resolution is best for your TV / projector. If ‘None’ is selected
the TV / projector will communicate with the source playing and ask for the maximum resolution


Sink turns it to RGB 12 bit but no Colorimetry is reported.

Only Full Bypass let’s it display properly. so something you guys changed has changed the way things are reported. I’m not seeing any video nasties as doing these quick tests, 1080p seems to be unbothered by anything


Banding is also pretty bad on 4k HDR using the Summit Entertainment test.


Well I’m stumped. AFAIK, an HDMI sink should never ‘ask’ for a particular resolution. It has a preferred resolution but it’s up to the source to choose a resolution from those offered by the sink.

So that’s telling us your processor is doing some voodoo. The only thing we have changed is sending 8-bit signals as 10-bit. It seems the processor is at least chopping off the bottom 2 bits, even in ‘full bypass’ but why it’s reporting RGB otherwise I really can’t say.

We need to do a bit more work on issues which are worse than yours for some users so hopefully this will get resolved.


Is this new with this upgrade? Have you reset attr?

echo now | sudo tee /sys/class/amhdmitx/amhdmitx0/attr

Then what does cat /sys/class/amhdmitx/amhdmitx0/config say?


I’d say the reason why it’s dropping to RGB 8bit is because you are outputting at 10 bit now. This would explain a few things relevant to the limitations of the 10.2Gbps sec board (I think)

i hope it does get resolved, It was my primary reason for purchase.


Think the banding went away after resetting attr (yes new upgrade)

osmc@osmc:~$ cat /sys/class/amhdmitx/amhdmitx0/config
cur_VIC: 16
VIC: 16 1920x1080p60hz
Colour depth: 10-bit
Colourspace: YUV444
Colour range: limited
YCC colour range: limited
PLL clock: 0xc000029a, Vid clock div 0x000b0000
audio config: on
3D config: off


All as expected, given the EDID is not advertising support for a bitrate capable of 4k@60Hz.


Yes, It can’t handle 4K60hz until the new board is finished which is 2.0b

If it’s displaying the right colours at 8bit at the right refresh rate then fine - It ‘seems’ to be fine on 1080p and seems a little punchier in 4K HDR.

Not sure what the next step is, if it just a matter of a flag I don’t care…

Cheers for the help!