i am running the latest plex media server on a Synology ds918+ and have had no problems playing to an apple tv 4k. however when playing a 1080p movie on my samsung nu8000 tv running the latest plex app it constantly stops to buffer.
any ideas what I’m doing wrong, I’m new to the NAS scene.Plex Media Server.log (1.0 MB)
The video is transcoding. The CPU in the DS918+ is not powerful enough to transcode 1080p in real time. That is why the video is buffering.
To remedy:
If possible, choose an audio stream that direct plays, either AAC or AC3.
When playing The Lego Movie 2, you picked dts, which is not supported by your TV. This causes the audio to transcode.
Do you have subtitles enabled? If so, turn them off.
If subtitles are enabled and the audio is transcoding, then Plex will transcode the video (This happens with my LG, and I’m pretty certain it is true for Samsung as well).
You can verify if things are transcoding by looking at the Plex Dashboard: Plex Web -> Status.
Additional Details:
The Celeron J3455 CPU in the DS918+ is not powerful enough to transcode 1080p video in real time.
If you had a Plex Pass, you could take advantage of Hardware Accelerated Streaming. This uses the GPU inside the Celeron CPU. This would let you transcode 1080p video.
The DS918+ will not reliably transcode 4K video in real time (i.e. w/o buffering), even with hardware acceleration. The CPU & GPU simply are not powerful enough.
See Plex NAS Compatibility List and Plex NAS Compatibility Guide.
The Synology website says, “Also capable of transcoding up to two channels of H.265/H.264 4K videos at the same time.” However, that refers only to Synology’s own video applications which utilize a dedicated chip on the NAS motherboard. Synology does not let Plex access the chip, so Plex must rely on the Celeron CPU. Hence Plex’s limitations when transcoding video on Synology NAS.
So the video is direct playing but the audio is transcoding.
However if I had plex pass and hardware accelerated streaming that would fix the issue?
Also there are now subtitles active that I’m aware of.
I misread the log and thought the video was transcoding. I missed this part:
Video=(id=18902 decision=copy width=1920 height=808) Audio=(id=18903 decision=transcode bitrate=768 encoder=aac channels=6 rate=48000
Hardware accelerated streaming only helps with video. Audio is always transcoded on the CPU.
A couple of other things to check:
You can do this via the Plex Dashboard or by logging into the NAS & using Synology’s Resource Monitor. Note: I think you can see CPU via the Plex Dashboard. If this requires a Plex Pass then use the Resource Monitor instead.
Also, how are the TV & AppleTV connected, wired or wireless? If wireless, how strong is the connection?
The cpu usage doesn’t go above around 30%
The Samsung tv is connect via wifi
The Apple TV on the lg in the other room is connect via Ethernet
However If I play the LEGO movie 2 on our bedroom tv which is an older model Samsung tv the movie seems to direct play the video and the audio.
Thanks for the info.
Older model Samsungs support dts. Samsung removed it recently, I think with the 2018 models.
I ran a quick test with my DS918+ & LG TV. I disabled dts in the Plex LG client to force an audio transcode, then played a 1080p blu-ray rip with dts audio. The video plays smoothly, w/o buffering. PMS transcodes the audio to AAC and uses ~5% of the CPU.
This shows the NAS can easily handle things, and leaves the network and the TV.
What is the wireless signal like at the TV’s location? Does the TV have anything that indicates wireless signal strength?
I’m trying not to jump immediately to “it’s a wireless problem.” But still need to make sure the signal is strong, no interference from neighbors on the same channel, etc.
I have the same NU8000 which I have wired to the server. It seems to me that direct streaming, which is what is going on, seems to be more demanding than transcoding. I had buffering and if it did play the audio would get out of sync. Thusly I disabled direct streaming in the TV app. All 1080 and most 4k worked just fine after.
xml.txt (11.3 KB) Plex Media Server Logs_2019-07-15_16-36-56.zip (3.7 MB)
I hope this helps.
ill have a read of the faq too
I uninstalled and the app on the Samsung tv and re installed it. Yeah don’t think it seems to have fixed it. Any idea on how I might be able to fix the problem?
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