Truehd 7.1 and Dolby Atmos configuration

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Edit: The audio transcoding problem is fixed in PMS 1.41.7.9823 (release notes).

PMS, Roku, & TrueHD

I’ve done some additional testing with Plex, TrueHD, & Roku.

There is a problem with PMS 1.41.7.9799 and playing TrueHD audio on Roku devices (my Streaming Stick 4K, anyway). If I fall back to 1.41.5.9522, then TrueHD transcodes OK (I did not test 1.41.6, I don’t have that version handy).

Here are the steps I used to fall back:

  1. Stop Plex Media Server
  2. In the Codecs folder in the Plex Data Folder, delete everything but the .device-id file.
  3. Install Plex Media Server 1.41.5.9522 (I did not uninstall 1.41.7 first).
  4. Start Plex Media Server

I could then successfully play movies with TrueHD 5.1 & 7.1 audio using my Roku stick.

Notes:

  • I do not know if the problem is decoding TrueHD, encoding to EAC3, or both. I did not go to that level of detailed testing.
  • If I play the same movies via Plex Web, they play OK. However, the audio is transcoding to AAC, not EAC3 (which seems to point to encoding to EAC3, but more testing needed).
  • I do not know if deleting the codecs is absolutely necessary.
  • I see the same problem with 1.41.7.9799 running PMS on my Synology NAS (expected, since it also runs Linux).
  • I’ve not tested with PMS on Windows or Mac.

Edit: Another report of same problem: 7.1 TrueHD transcoding crashes after upgrading Plex Media Server to 1.41.7.9799


The database size issue

Since you ran the beta builds, check the sizes of your db files.

On my server, it blew up from 220 MB to 30+ GB. PMS still worked, but the system was sluggish.

I fell back to 1.41.5 to stop the growth (before 1.41.7.9799 was available), then used the SQL commands in the Library.db size thread to remove the extra statistics.

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