Display MoreHi HiassofT
my fault, i ask this not about Pi4. My AVR (Denon X4100) has HDMI 2.0 but only HDCP 1.4.
If i go from PI --> AVR --> TV i get no HDR.
If i go from PI --> TV i get HDR.
Is it not possible with HDCP 1.4 to get HDR?
I tried a HDCP Converter, but this doesnt work too.
If your AVR has HDMI 2.0 support but only supports HDCP 1.4 (and not HDCP 2.2) then that could mean it was one of the first gen UHD AVRs that had HDMI 1.4 inputs and outputs in hardware terms but that got very basic HDMI 2.0 support added (in the same way nVidia added HDMI 2.0 support to their HDMI 1.4 Graphics cards and Sony added HDMI 2.0 to existing HDMI 1.4 UHD TVs via a software upgrade)
The way they did this was to add support for just the 4:2:0 HDMI 2.0 mode for 2160p50 and 2160p60 modes - as HDMI 1.4b already supported 2160p23.976-30 at 8-bit in SDR using 4:4:4/RGB and 12-bit using 4:2:2 (though this mode may not have been supported).
Using the 4:2:0 subsampling introduced with HDMI 2.0 allowed HDMI 2.0 4:2:0 2160p50 and 60 modes to fit into the hardware restrictions of an HDMI 1.4b connection (i.e. you could add HDMI 2.0 basic compatibility using HDMI 1.4b hardware). AIUI this was 8-bit SDR only, and that may also have been true of the HDMI 1.4b 2160p30 and below support also supported. (i.e. you get UHD support at all frame rates in 8-bit, but you don't get HDR support as that would require 10 or 12-bit support - which may not be implemented)
The Pi 4B doesn't support 4:2:0 HDMI output as I understand it (as it would require both vertical and horizontal subsampling of chroma - and the Pi can only really do horizontal (?)
This may also mean your AVR is not HDR compatible ("passthrough" in AVRs isn't helpful in that regard)
The lack of HDCP 2.2 support is a strong suggestion that your AVR is one of those early HDMI 1.4 models that got a partial upgrade to HDMI 2.0 - though I may be wrong.