[SOLVED] HLG HDR output flagged as HDR10 PQ

Single Board Computers Odroid N2/N2Plus/C4
16

OK - am back with my UHD HDR TV and AVR. Both of which are HLG compatible.

Here’s dispinfo output in idle whilst displaying 1080p50 SDR without any video playing http://ix.io/21p2 (Interestingly this seems to suggest it thinks my AVR+TV combo isn’t HLG compatible?

------------ /sys/devices/virtual/amhdmitx/amhdmitx0/hdr_cap ------------
HDR Static Metadata:
    Supported EOTF:
        Traditional SDR: 1
        Traditional HDR: 1
        SMPTE ST 2084: 1
        Hybrif Log-Gamma: 0
    Supported SMD type1: 1
    Luminance Data
        Max: 0
        Avg: 0
        Min: 0

HDR Dynamic Metadata:

colorimetry_data: c3

When I play the short sample.mkv clip of Seven Worlds, One Planet without making any changes I get this : http://ix.io/21p3

It’s output in HDR10 mode - but looks like it may be being converted from HLG to HDR10 - at least partially.

If I then type echo 1 > /sys/module/am_vecm/parameters/force_pure_hlg the TV goes into SDR mode and the picture looks correct (for HLG displayed backwards compatibly with SDR). I can then manually force my TV into HLG mode. My guess is that the N2 doesn’t think my TV / AVR is HLG?

dispinfo gives me this http://ix.io/21p4

I’ll try and take my AVR out of the chain - but both my TV and my AVR support HLG.

I’ll give Android a go too.