DTS transcoding to Dolby 2.0 rather than 5.1 on Firestick

Plex Players Streaming Devices
1

Server Version: 1.18.4.2171
Player Version: 7.25.2.14287

First, here’s my setup;

Server
PMS Version 1.18.4.2171

Client
PMP Version 7.25.2.14287
Firestick 4K
FireOS 6.2.6.8 NS6268/2315
Samsung UE46ES7000
Sonos Beam

Observation
When I play content that has an AC3 5.1 audio track everything plays fine, and the Sonos app shows Dolby Digital 5.1 as the source reaching the beam, so that part is working. However, when I play a file that has a DTS audio track (and yes, I know the Sonos doesn’t support DTS) then the Sonos reports as receiving a Dolby Digital 2.0 signal, so Plex is transcoding to 2.0 rather than 5.1.

Attempted Fix
The Firestick is the only Android device on our network, so I tried changing the Android.xml profile on the server to specify aac as support 6 channels (the default file read 2), but this had no effect (see excerpt below). I have come across reports that this is a firmware issue in the Firestick which causes the problem, but they all seem over a year old and I’m hoping (wishfully!) that something has been done about it in this time by either Amazon or Plex. Is there another way to force PMS to transcode from DTS to 5.1 and not 2.0? Or am I stuck converting all my DTS content to 5.1 on the server-side?

Android.xml profile changes

Original

<VideoAudioCodec name="aac">
  <Limitations><UpperBound name="audio.channels" value="2" /></Limitations>
</VideoAudioCodec>

Modified

<VideoAudioCodec name="aac">
  <Limitations><UpperBound name="audio.channels" value="6" /></Limitations>
</VideoAudioCodec>
2

This has now been resolved.

Counter intuitively, setting the Audio Pass Through to optical in the Plex app (even though everything is connected via HDMI) means all non-AC3 5.1 transcodes correctly and I can play DTS / DTS-HD without problem.

For anyone who stumbles across this thread, for reference the issue was resolved here https://www.reddit.com/r/PleX/comments/ekv7hb/dts_transcoding_to_dolby_20_rather_than_51_on/?utm_source=share&utm_medium=ios_app&utm_name=iossmf

2 Likes
3

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.