2017-12-21, 22:28
(2017-12-21, 21:31)wesk05 Wrote: [ -> ]This sounds interesting. How can we confirm the issue either way.(2017-12-21, 19:24)Herakles HD Wrote: [ -> ]If that was the case, wouldn't it report a 8-bit signal for 4:2:0 10bit as well?No, it would report 10-bit 4:2:0 as 10-bit (or 30-bit) because as per HDMI 2.0 specs, >8-bit 4:2:0 is Deep Color pixel encoding and will therefore use the color depth bit in HDMI GCP.
But it actually shows "4:2:0 30 bits" if I set the SHIELD to "Rec. 2020 4:2:0 10bits" and "4:2:2 24 bits" if I set it to "Rec. 2020 4:2:2 12bits".
Furthermore I can clearly see the quantization artifacts in the Spears & Munsil test video for the 4:2:2 12bits setting but not for the 4:2:0 10bits setting.
Which leads me to the conclusion that the signal for 4:2:2 12bits in fact has only 8bits instead of 12bits as shown in the info.
If you are seeing banding on your display with 4:2:2 input, then it suggests that your display is not processing the 4:2:2 signal correctly. Have you tried with a different device that can output 10/12-bit 4:2:2?
What I can say is that 4:2:2 12bit from my Oppo (Bluray UHD discs play correctly with HDR and no banding), suggesting my TV's are handling it well.
Playing 4:2:0 10bit content from the Shield at 50Hz plays fine (no banding)
From what I recall 4:2:2 12bit Display setting on Shield results in 8bit output at 24Hz (according to my Oppo's input)
Both my 4K TV's are OLED and they are grey-scale calibrated (though HDR mode less so) so banding is perhaps easier to notice
4:2:2 12bit is the correct way to send HDR content to TVs (at any framerate) and content will mostly have come from a 4:2:0 10bit source.
Anyone know how to add suitable debug into Kodi or what to look for in Android logcat (or elsewhere) on the Shield?