[Bug] Plex transcodes video when it should only transcode audio

[Pov_goose]

Server Version#: 1.23.4.4775
Player Version#: latest

I’ve noticed for a while that Plex seems to transcode video unnecessarily when attempting to play back files with a TrueHD track. There isn’t an issue for files with other audio codecs eg. AC3, DTS (all flavours)

I even have some media that has a TrueHD track and an AC3 compatibility track; that transcode video if the TrueHD track is selected vs the AC3 track.

This wasn’t an issue some time ago, so it’s clearly a bug. If the client can play the video track there shouldn’t be a need to transcode it simply due to audio.

This also doesn’t seem to be a new issue given this older thread from last year.

TrueHD Audio seems to be triggering a full transcode not just audio

I’m not sure exactly when this happened (app update or PMS update I’m not sure) but when playing any video with TrueHD audio plex has issues… it used to just transcode the audio, but it’s no longer that simple. The main issue seems to be will 4K HDR files. previously (and this has only recently changed) a HDR file with a true HD audio track would get the audio transcoded and the video would play directly, but now the whole file is being transcoded, smashing my CPU and losing the HDR. But if I s…

This is particularly grating on my specific content that has UHD HEVC video along with a TrueHD (5.1,7.1 w/wo ATMOS). My server struggles to handle the transcode so it would be great to see this one fixed.

I can supply whatever logs are necessary and possibly sample files but this should be pretty easy to replicate.

[FordGuy61]

Looks similar to another report: Audio transcoding causing video transcoding

Plex client version?
Client device - Shield, FireStick 4K, etc?.

• Set your server for debug, not verbose, level logs. See Reporting issues with Plex Media Server.
• Enable logging in the Plex Android TV app. See Android, Android TV, Fire TV, Portal Logs
• Play one of the problematic movies/shows for 15 - 30 seconds (to capture the problem)
• Stop playback, wait 1 minute (to let the server capture everything)
• Pull server and client log files and attach to thread.
• Gather XML information for the movie/show with which you ran the test. Save as a .txt file and attach to the thread. See Investigate Media Information and Formats.

[abstr4ct]

I believe i have the same issue.