video transcoded when 2nd audio stream selected



I have this one movie - xml attached - which contains 3 audio streams. It all works fine as long as I select the 1st audio stream for play back. If I select the 2nd or 3rd one, plex suddenly decides to transcode the video (h.264 -< h.264) and audio (aac -> aac) streams.

I could understand if there is a need to remux the streams. But I can not imagine a necessity to transcode any of the streams.

I see this only happening in Plex web. Streaming the same movie to my iPad does not show this strange behaviour. It runs fine with all 3 audio stream without any transcoding.

I also have other movies containing more than one audio stream and have never seen this oddity. What is going on here?

I checked plex web app with safari and firefox on a Mac. Same bahaviour.

Plex web app 3.37.1; Server

  1. activate debug logging (not ‘verbose’!)
  2. quit Plex Server
  3. wait 1 minute
  4. start Plex Server
  5. wait 2 minutes
  6. Play the movie
  7. wait 3 minutes
  8. fetch log files and attach them here

Or look at the Plex Media Server.log file yourself.
Filter for lines starting with MDE:
Those explain the transcoding decision.



I intended to capture the logs files for you over the weekend. However, the problem is gone. I can only speculate that the update to plex web app 3.37.2 solved it.