Server Version#: 1.23.0.4497-a1b1f3c10
Player Version#: 8.16.2.24953 (ecc9cc06)
I know this has been a topic, but I need help troubleshooting mine specific to my devices.
Server is on my desktop, and I cannot play the new Lord of the Rings films in 4k without buffering every 5 seconds on the Plex app on my TV. Original quality says the 4k is playing at 76mbps which really isnt that high. I believe Im having the issue because its trying to transcode the TrueHD 7.1 audio because when I switch it to the 5.1 it runs fine in 4k. There has to be a workaround for this… The video format is HEVC.
I can provide logs if it helps. Since it seems audio related, I have tried running with HDMi passthrough on and off. One thought I had was it may be due to the soundbar I have connected to the TV with an optical cable. But it seems like a stretch for Plex to be transcoding for a connected device… I would think it would only be able to tell the TV specs…
-TV is a Sony XBR930e
-PC with plex server
-CPU: I7 8700k
-GPU: EVGA 1080Ti
-Internet
-Xfinity with 800mbps download, 19mbps upload
-TV is hardwired to the 1GB x1 modem right behind tv
-PC is hardwired to the same modem with a cat6a ethernet cable
Consider just playing the AC3 5.1 audio track, as your setup does not support playback of TrueHD without transcoding.
The AC3 audio track from the movie is likely of higher quality than a transcoded TrueHD audio format. The AC3 track from the movie is a studio provided 5.1 mix, usually at 640kbps. The Plex transcode is a 7.1 to 5.1 mixdown at a Plex chosen bitrate (you would have to check the logs to find the bitrate).
TrueHD audio will always transcode for your setup:
It is not natively supported by the TV.
An optical connection limits you to AC3 5.1 / dts 5.1 / PCM 2.0 audio, so the TrueHD would not pass to the soundbar anyway.
You would need a TV and soundbar that both support HDMI-eARC to pass TrueHD audio from the Plex app on the TV to a soundbar.
If available, try switching to 5 GHz WiFi.
The TV has a 100 Mbps Ethernet port. The video may be bursting over 100 Mbps resulting in buffering. 5 GHz WiFi may provide higher throughput than a wired Ethernet connection.
Monitor playback via Plex Dashboard. I believe the Now Playing window will show when the stream is buffering.
Also, watch the bandwidth graph. Plex traffic is not smooth. It normally bursts to the limit of the media when refilling the client’s receive buffer. If you see flat-topped peaks around 100 Mbps it indicates you’re hitting the limit of the wired Ethernet connection.
If you are also using subtitles while transcoding the TrueHD-Audio track,
the addition of subtitles can/may force plex to transcode the video and audio which is another possible cause of the buffering
