Plex Server Transcodes instead of Direct Play

Plex Players Smart TVs
1

Server Version#:3.98.1
Player Version#:4.0
Hardware: Intel 6700k and GTX 1080Ti.
Hardware acceleration is turned on.

Hi.

I have an 2018 SmartTV from Samsung.

When I try to play this file it transcodes it instead of direct play.
However the if I take the file and place it on a memory stick the TV plays the file perfectly fine, so it should be able to direct play it.

This results in high GPU usage and a lot of interupting playback ( Buffering )

So got two questions:

  1. How to get this file to Direct Play?
  2. Should not the GTX 1080ti be able to transcode 4k ?

The GPU is doing the transcoding, as one can se by the pictures https://photos.app.goo.gl/gENkjEM4V2sViidP9

File info:
Duration 2:03:41
Bitrate 24599 kbps
Width 3840
Height 2160
Aspect Ratio 1.78
Video Resolution 4K
Container MKV
Video Frame Rate 24p
Video Profile main 10

Duration 2:03:41
Size 21.00 GB
Container MKV
Video Profile main 10

Codec HEVC
Bitrate 18610 kbps
Bit Depth 10
Chroma Subsampling 4:2:0
Color Primaries bt2020
Color Range tv
Color Space bt2020nc
Color Trc smpte2084
Frame Rate 23.976 fps
Height 2160
Level 5.1
Profile main 10
Ref Frames 1
Width 3840
Display Title 4K (HEVC Main 10 HDR)

2

Samsung Smart TV 2018 or newer are not compatible with DTS. If your file has DTS audio and subtitles enabled, your server will transcode video.

3

That being said, my Dad’s 2018 Samsung MU6400 has the ‘DTS’ option in the Plex app, and plays files with DTS without transcoding. I wonder if it’s detecting that it’s using a sound system for audio out (that does support DTS)…

Also, SRT subtitles are supported now without the need to transcode.

4

The soundtrack is TrueHD and regular AC3 5.1.

5

you need to manually select the ac3 5.1 soundtrack, plex will use the default truehd audio (which is typically not compatible with smart tvs).

may or may not help @ [INFO] Plex, 4k, transcoding, and you - aka the rules of 4k

6

Thank you for the link.

Turned out PGS subtitle was the cause.
Looks like if I download srt subtitle it’s direct playing.

2 Likes
7

PGS subtitles will always trigger a transcode. Avoid them if possible.

8

Samsung MU were the last ones with DTS support afaik. Samsung dropped DTS starting with the NU series.

9

You’re right - the MU6400 does support DTS despite being a 2018 model.

Does anyone know if you connect a DTS capable sound system via htmi-arc to your TV, will Plex still play direct play DTS? Or does it have to transcode the audio before passing it on to the sound system? I want to upgrade my 2016 Samsung to a newer Samsung model at some point, but I won’t be doing this if I can’t play DTS soundtracks.

10

No, if the TV doesn’t support DTS it will not pass it through to the sound system. The choice would be a streaming box connected to the receiver and the receiver passing the video to the TV. You have several options here like nVidia Shield, Roku, Apple TV and an assortment of Android boxes. You’ll find a lot of info on them here on the forum, choose the one best suited for your media.

I’m still happy with my 2016 KS series and will hold on to them for at least a couple of years especially because of the sound support.

2 Likes
11

Ah, that confirms what I thought: without the DTS licensing the set won’t even pass through a DTS track to another device via ARC.

1 Like
12

Looks like I’ll be hanging onto my KS7000 for a while longer too then!

13

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