Server Version#: 1.15.6.1079
Player Version#: 3.98.1
Hey everybody! I tried searching for the answer here and although I got some mentions I didn’t really find an answer.
I have a Samsung NU7400 TV which doesn’t support DTS. I tried playing a 4K DTS-HD MA movie and it was stuck on buffering. Every possible setting is on maximum, TV is connected to the router via LAN, server is a PC with a i5-6500, 16GB RAM and a 6GB NVIDIA 1060. Dashboard says Direct for the video, but transcoding the DTS to AC3. I’m getting stuck on buffering every 10-15 seconds, but I see no high resource usage on the PC - disk is quiet, CPU is at 15%, so something doesn’t add up. I found a nice tool that fully transcoded the entire movie into AC3 (kept the video same as original, file size almost didn’t change). It took the tool 30 mins to convert a 3h movie, so I’m confident the PC can handle it. Anything I’m missing?
well you have already identified the main problem, your tv doesn’t support dts, so plex has to convert the audio, which your specs appear to be fine for converting audio
make sure subtitles are disabled too.
post a screenshot of your dashboard with a problem video
my guess is your tv is only 100mbs and the video bitrate exceeds the tv bandwidth. and/or you have other network problems.
you could try a wifi connection on your tv (if it has wifi) to see if that improves or makes things worse.
Thanks for the reply! I will get you the screenshots and I will further rule out connection issues - I’m getting a decent router tomorrow that can come close to 100mbit over wifi (AC1900).
That being said - I doubt it’s the bandwidth itself. The converted movie (AC3 sound) shows a bandwidth usage of 63mbps and the DTS-HD MA audio is reportedly 16mbps so we are still comfortably in the 80mbps range. I’m almost sure it’s some issue with transcoding speeds but I will get back to you with logs and stuff.
I have an nu8000 and these are the things I have seen and heard of. Your problem could be one of two different things, or all at the same time.
The network would be an issue when transcoding or direct streaming a 4K file on a lan. People have mentioned speeds as high as 165 mbps when transcoding. this obviously exceeds the limit. Direct streaming if I remember hits around the 120’s. Direct Playing is usually well within the 100 mb limit.
Another thing I have noticed that, direct streaming has issues from the server. So I disabled the option in the app. Audio out of sink, buffering, etc… Transcoding works much better as long as there are not subtitle issues.
As you can see even though the video codec is exactly the same, when I try the DTS it direct STREAMS the video and transcodes the audio, while the converted is both Direct Play. I tried turning OFF the Direct Stream option and playing the original - this happened:
I guess it’s only logical that if it has to transcode the audio it has to transcode the video as well. When I force it to not Direct Stream it tries to transcode BOTH audio and video. The result is a bandwidth requirement of 236 mbps which is obviously not happening over a 100mbps network. I’m getting a gigabit router tmrw but I doubt that the TV has a gigabit port. It will still allow me to test if this is a connection issue, although I grow doubtful
When it transcodes it does do both audio and video. Direct stream will only transcode the audio and merge it back with the video (this is where I had issues).
The router won’t help because the bottleneck is at the tv. Doing it wirelessly may help but I have only seen mixed results. Samsung says it will only do 100mb also but some have tested it with higher results.
The solution I do is to have the file converted to x265 with ac3 audio using handbrake. 264 is usually too big of a file, and you may have issues.
With smart tvs the only answer is to have things direct play. Transcoding is not possible for 4k, you get mixed results in 1080, and 720 usually has no issues. And it is usually caused by the network.
router won’t help when the tv port is the bottleneck.
your best bet is when you rip your 4k disks (that is what you are doing right, because using files of mysterious sources would not be supported here) uncheck the dts audio stream(s) and use or convert to ac3 5.1 or stereo before adding to plex.
I’ll do some testing with 1080p and DTS. If not - I can convert it to AC3 I guess, nothing you can do about it. @jeffddntdt converted was dual direct play, worked like a charm, 5.1 audio sounded decently on the home theater receiver. If the transcode, even if it works, results in other performance issues I’ll rather convert all my stuff - I can live with the 30 minutes wait. Thanks to you both!
I had a similiar issue.
I think this is DTS transcode problem.
I have an 8 thread low power intel CPU. 7700T
I have hw transcode (with plexpass) enabled in docker, and it works.
I have 100Mbit to the samsung NU 8000 TV.
Samsung can’t decode DTS, so it transcodes it to AAC 5.1 (i think it’s ac3, cos my soundbar can play it, and aac is not supported by the TV over ARC)
the audio transcode can only use 1 thread. When I monitor the server (unraid), I can see that 1 thread is hammered at 100%, and it can’t keep up (7th gen desktop CPU!!), so every minute I have a buffer for a few seconds.
The bandwith is fine, the video is not transcoded, and even if it were, it wouldn’t hit the CPU, cos HW video transcode works.
subtitles are off.
SO it is a DTS to AC3 transcode issue, which is CPU only, and i don’t think it should take 100% cpu on a single thread.
is there a difference between DTS and DTS-HD? I think DTS HD has the original DTS core for compatibility.
I will test further.
according to tautulli, it is transcoded to 768 Kbps AAC
It’s a 40.0 Mbit video stream btw (idk why plex reports double), and my network can handle it, even with WIFI. the track is named DTS HD MA, but it’s the core track, which is 1536kbps. DTS HD is 3-4-5Mbit usually.
OK, now I’M VERY CONFUSED, but I think I found the reason, IT JUST DOESN’T MAKE ANY SENSE.
so DTS to AAC stereo or 5.1 is FINE. CPU usage is low, not 1 thread is pinned.
If I enable subtitles, 1 core is hammered, my video is not reencoded, but tautulli says for the subtitles that SRT to ASS.
is there a subtitle transcode, without video transcode? plex.tv says directstream
hw encode is working on other files, but it wasn’t triggered and it would use all the cores anyway.
the source subtitle is SRT, and the tizen app can play back srt without transcode.
very weired
any ideas? is this a bug, is this expected? there are PGS subs in the video stream, but they are not selected, they are japanese, and in case of PGS, it wouldn’t be directstream anyway.
what does SRT to ASS mean? anyone?
I gave up trying to get Plex to work with DTS ages, it’s just too much hassle… also irritating that my TV (NU8000) doesn’t support it.
I’ve started using Handbrake to create AC3 tracks from the DTS ones a compatibility track and MKVToolnix to add them back into the file.
I have the same TV NU800, and ironically an older Samsung 4k from 2016 or 2017. My newer, nicer TV (The NU8000) does not support DTS at all… yet my older crap TV supports some DTS options, and can direct play from my server… whats the deal? Seams like Tizen needs to update their OS, or better yet… Plex can allow full passthrough. I would love to be able to passthrough all audio to my A/V receiver to handle.
Also, I have my Plex server running off of a Intel NUC, it transcodes DTS signals to AAC just fine. I have noticed issues with it not being able to do anything with TRUEHD though… I think a Plex server update is in order before it can do the brains to transcode that one.
I have e Samsung Q9FN which needs to transcode from DTS to AAC. I found in another thread that the problem could regard videos with 23.976 fps instead of 24. no matters if 4k or 1080 resolution.
According to that, it seems that there is a bug in plex for samsung app when it transcodes a 23.976 video. I tried it on my pc too and it works fine (web browser and w10 app both)
