Updates: I was able to make some progress by changing line here to look for a 6 instead of a 7. This enables the DV options in the CoreElec settings menu. When trying to play DV files my TV does not engage DV mode and CoreElec shows that the output 12 bit YUV444 in SDR. In dmesg, however, I did find
[ 258.003964@0]d hdmitx: hdmitx: Dolby VSIF, VEN_DB2[3]) = 0
[ 258.003973@0]d hdmitx: hdmitx: Dolby VSIF, switching signal to SDR
[ 258.003985@0]d hdmitx: vic:16, cd:4, cs:2, cr:1
but have yet to work out what that means.
More interestingly, in dmesg I also found
[ 286.118492@0]h [tsync_avevent_locked 1064]VIDEO_START-tsync_mode:1(S)
[ 286.118500@0]h pcr:0x0,param:0x0,vpts:0x0,apts:0xffffffff
[ 286.118638@0]h Creating Dolby Vision metadata parser instance success
[ 286.118722@0]h DV:[0,0,12,DOVI,2968,0]
I find this more interesting as it indicates success in creating a metadata parser instance. I don’t know if this message is incorrect, if the message shows that not all parts of dolby vision require a licensed chip, or that the chip actually is licensed. Does anyone know how to determined which of these it is?
Adding to my uncertainty is that it appears that this message comes from the dovi.ko - this is based on me not being able to find the text string Creating Dolby Vision metadata parser instance success in the corelec code, but in the file dovi.a.c provided by @djnice in this post.