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

[ronand]

Most "downloads' are using the AAC codec and will only play back as stereo no matter how many channels they have. You can use a program called mediainfo on a PC to check exactly what is used in a file.

[steveharman]

Fantastic, just what I needed to know. Downloaded the Mac version of "mediainfo" and sure enough, 90% of my downloads are 2ch.

Disappointing, but at least I have my answer. :-). Many thanks.

[ronand]

Another thing to bear in mind is that your amp is quite old and probably doesn't handle multichannel AAC - its worth checking the manual.

[steveharman]

Thanks. I noticed there are various transcoding options in Menu > Setup > Audio & Video > Settings including "AAC transcoding". Is it possible to enable AAC transcoding > ac3 and magically expect my multi-channel AAC downloads to present as AC3 to my amp (which it plays back perfectly in 5.1)

[ronand]

I've no idea - what are the options it gives you?

[twol]

Thanks. I noticed there are various transcoding options in Menu > Setup > Audio & Video > Settings including "AAC transcoding". Is it possible to enable AAC transcoding > ac3 and magically expect my multi-channel AAC downloads to present as AC3 to my amp (which it plays back perfectly in 5.1)

Try it & see what happens!

[Joe_90]

Another thing to bear in mind is that your amp is quite old and probably doesn't handle multichannel AAC - its worth checking the manual.

Just as an aside - almost no AV amp will handle AAC natively over HDMI. You need to get the box to transcode AAC to AC3 or PCM. My Sony DN1060 will handle all sorts of exotic Dolby and DTS multichannel formats over HDMI, but not AAC.