Last night I was playing a 4K DV movie that contained both TrueHD Atmos 7.1 and EAC3 5.1 audio streams. The TrueHD track is listed as the primary/default audio track. When I was playing the movie on my Fire TV 4K Max, which does not support TrueHD decoding, PMS decided to transcode the TrueHD 7.1 to Opus instead of attempting to playback the natively compatible EAC3 5.1 track. This became a major issue when I attempted to enable subtitles as this forced the 4K DV video to also transcode to burn the subtitles (I understand this is an issue with transcoding audio and subtitle synchronization). The issue was difficult and time consuming enough for me to track down why the stream wasn’t able to play (due to the server not being fast enough to transcode 4K → 4K w/ tone mapping and subtitle burn-in), and will be nearly impossible for my other family members to figure out why some streams do not work.
In order to enhance the user experience for all end users, can the functionally to auto-select the best natively compatible audio stream be integrated and automatically enabled or a setting created to prefer this functionality before attempting to transcode audio streams and run into the above issues with subtitles and potentially less optimal audio playback on certain clients and home theater systems without certain audio codec compatibility? This may be similar to DV with HDR10 fallback, where the video stream will fallback to HDR10 if DV is not supported for video streams containing both metadata.
Server Version#: 1.32.1.6999 (waiting on Linux Intel HW transcoding regression fixes)
Player Version#: 9.23.0.1746
I have been wanting the same feature for some time now. Roughly 90% of my movies and TV shows are in H.265/HEVC with 3 audio tracks (in order of quality and respective track ID in the MKV):
Ideally, Plex would assess the selected/default track upon clicking “Start” (typically #1) and determine if Direct Play is achievable on the client. If not, move down to #2 and repeat until it does. If AAC stereo is still incompatible, transcode as a last resort…essentially if/then/else statements in pseudocode.
This is exactly the issue I was running into. TrueHD is essentially always track id 1, and usually there’s at least an AC3/EAC3 fallback as track id 2. Most streaming devices can’t decode TrueHD, so that causes unnecessary audio transcoding for the majority of clients out there
Taking a look at some of the similar threads across the years, it appears this feature topic hasn’t gotten much traction. Understand it doesn’t break the core functionality and is more of a quality of life (QoL) fix so it probably doesn’t hold much weight in terms of priority.
Does anyone know if this feature is still being considered? Happy to move it to the feature section for better visibility
I use a Shield TV Pro in the basement theater (5.1.4 setup), it can play TrueHD w/Atmos. In the Family room (5.1 setup) I have Fire TV 4k Max and Roku Ultra, and a Roku Ultra in the bedroom (just TV speakers).
Changing the default audio track isn’t a help.
I hate when I start a movie, and realize it’s going to transcode and I have to manually change it.
I would love it if Plex would try the next audio track if it will direct play on this device.
