Audio transcoding question/issue

[BillOatman 596]

I was trying out some dolby digital demo clips today and am seeing something I don't understand.
Normally it works fine, but some of these files are VOB so Emby transcodes it due to the container.  However what it transcodes it to has me curious.  This is what the video shows as it's audio in Emby.

 

Note AC3 5.1

In the nerd stats it shows 

 

Note original audio is dolby 5.1 which is correct and it is being transcoded to AAC 7.1 ???

My (antique) soundbar is a samsung HW-D450 connected to my samsung TV via optical cable.  The TV is connected HDMI to a shield.

Attached are the server and transcode logs.

It plays non-vob DD 5.1 files just fine with no transcoding.

You can get the file here

embyserver.txt ffmpeg-transcode-3679e912-f992-4e9f-8ad7-c3c8f29dfcf8_1.txt

Edited May 29, 2021 by BillOatman

[Luke 42079]

Hi, the stats display there is incorrect. It's being transcoded to 5.1.

[BillOatman 596]

23 minutes ago, Luke said:

Hi, the stats display there is incorrect. It's being transcoded to 5.1.

Occam’s razor, should have been my first guess   Thanks!

[ebr 16184]

12 hours ago, Luke said:

Hi, the stats display there is incorrect. It's being transcoded to 5.1.

Only the channel count is off.  It is transcoding to AAC because the HDMI connection must be reporting no support for Dolby Digital.  It is the optical that is probably tripping it up here.

[BillOatman 596]

1 hour ago, ebr said:

Only the channel count is off.  It is transcoding to AAC because the HDMI connection must be reporting no support for Dolby Digital.  It is the optical that is probably tripping it up here.

I handbraked them all to mp4 from VOB and no transcoding at all now, so it stays dolby and 5.1. So it seems needing to transcode due to the container triggered the weirdness.

The TV itself does not have dolby support but it passes it down to the soundbar via optical. The test files being played clearly demonstrate the 5.1 is getting there, so all is well