Confused by 5.1 / Dolby surround settings!

[steveharman]

I've just changed our old Sony AV amp for a slightly less old Onkyo TX-NR676 amp.

FTA TV identifies fine as Dolby 5.1/Surround on the amp. Test files I've downloaded for DTS-X also identify fine on the amp (and sound great) along with some Atmos encoded 2160 files. However, I'm having no luck with any movie downloads being detected and played as 5.1. Everything I try just shows as "PCM", without the Dolby logo and "Surr" label that FTA TV shows.

I appreciate "movie downloads" is a pretty vague term, but I'd have thought that any mainstream movie of a decent rip quality from the past few years would be at least Dolby 5.1 and the amp should detect them as such? Which leads me to think I may have something misconfigured on my box.

Currently, it's running OpenVix 5.3 (overdue for an update....). I've attached a screenshot of my audio config from Menu > Setup > Audio & video.

Thanks,

audio_settings.jpg