Server Version#: latest public
Player Version#: latest from samsung smart hub
I’ve got a Samsung 4K Smart TV from 2020 and it does not support DTS audio. However it does support the traditional AAC etc.
I just finished installing Plex Media Server (latest at this time of posting, public branch) as well as installed the latest version of Plex Media Player from Samsung app store.
Now I want to play a 4K video file that is in H265 and has 2 audio streams (AAC and DTS) and avoid video transcoding. When I select AAC it plays normally and video and audio appear as Direct play. But when I select DTS, it transcodes both, video and audio.
To my understanding Direct stream is supposed to copy and stream the video as is, while in this case transcode only the audio to something that the tv supports (AAC in this case). So why does it not do that? Or am I misunderstanding something?
Enabling text subtitles when the audio is transcoding results in a video transcode.
Enabling PGS or VOBSUB subtitles at any time results in a video transcode.
Configure the Plex app on the TV to log to the server at the debug level.
With no other streaming activity, play the movie with dts audio and without subtitles, for ~30 seconds. Stop playback.
Wait 1 - 2 minutes for the logs to catch everything, then pull the server log files. See Plex Media Server Logs.
Attach the ZIP file to the thread (drag it into the message window, it will attach at the cursor location).
Pull the XML information for the movie. See Investigate Media Information and Formats. Save the information as a .txt file or zip it. The forum does not support .xml attachments.
If you want to dig into the files, examine the Plex Media Server.log file. Look for lines with MDE: or MediaDecisionEngine. These generally tell why a stream is transcoding. The MDE: entries are logged by the Plex server. Those with MediaDecisionEngine are logged by the Plex app.
Plex for Samsung
20_KANTSU2_UHD_BASIC
Client Version: 5.6.1
Platform Version: 5.5
And attached are the server logs after playing a 4k hdr movie with dts audio and no subtitles.
With no subtitles selected and Any audio track selected, I noticed that the video does Direct Stream but is artifacting every few seconds and is unwatchable. The audio is being transcoded but into AAC instead AC3.
I also have some 1080p content in x264 and AC3 (same as for the selected movie) and everything is direct playing even with srt subtitles while for the movie above apparently no subtitles have to be used in order to get it somewhat to work but still being unwatchable due to the artifacting and low quality audio codec choice from the TV.
Edit: Also worth mentioning that when a file plays with AC3 audio as its default audio track, it will direct play everything but the bandwidth on my 2.4ghz network gets maxed out for SDR content.
The 2020 Samsung devices use HLS to play video because the devices have issues playing DASH for whatever reason. Because it’s HLS, we can’t Direct Stream video and transcode audio without other issues occurring. We’re in the process of trying to get the DASH issue resolved with Samsung so we can switch back.
I will be looking forward to an update like that. Do you have any alternative solutions until then, such as manually converting audio to a matching format and making it default for Direct play to work etc?
@edispIex I did not see anything unusual in the log files. With subtitles turned off, the video was direct streaming and the dts audio was transcoding, which is expected.
You should look at updating your network. If the TV is on 2.4 Ghz wireless and struggling with SD, then there is no way it will handle 4K HDR media. The version of Tenet you were watching probably uses 25+ Mbps of bandwidth. Most SD media runs in the neighborhood of 2 Mbps.
The Ethernet port on your TV is most likely 100 Mbps. I’ve yet to hear of a TV with a 1 Gbps port.
A 4K HDR Blu-ray rip can burst over 100 Mbps resulting in buffering if the TV is on wired Ethernet.
A strong 802.11ac 5 GHz WiFi network will give you over 100 Mbps of bandwidth.
I’ve an LG TV. When on wired Ethernet it would buffer when streaming some high bit rate 4K HDR movies. I dropped in an 802.11ac access point behind the TV, using the Ethernet cable for backhaul to the main router. The TV connects to the AP on the 5 GHz channel. No more buffering.
I want to reply back that I managed to find a temporary workaround.
Since the TV likes to default the transcode to AAC, I used ffmpeg to convert the audio into AAC 5.1 and made sure that is the only audio track inside the mkv file. With some batch and bash scripting it can be made simple to do all that to every mkv file with one click.
Now the TV direct plays video and audio, also srt subtitles work without transcoding.
I’ve went back to the old app on the tv and it didn’t have any issues anymore. Just last week I’ve moved again to the new app and it appears not to have issues anymore either so I can’t really say much.
Which TV model and firmware version do you have? Asking because everything is updated, but it’s still transcoding everything whenever it can’t direct stream audio.
I also seem to experience some weird behaviour on the latest version of the Plex Samsung TV app on my " Samsung 65" Q90R 4K UHD QLED Smart TV QE65Q90RAT (2019)".
I tried to play a TV episode the other day (on my Local Network) in the MKV container and with the codec “HEVC 5.0 Main 10” with “Opus Stereo” audio format and AAS Subtitles. As I understood Opus is not yet supported on the Samsung TV app (I really hopes this changes on the future), but I would atleast expect the audio to be transcoded, were the HEVC video would just be Direct played together with the ASS Subtitles. But in my case the Samsung TV app ended up just transcoding both video and audio.
I do have maximum streaming quality enabled in the tv app settings for both Local Network and remote Network. And I do have Direct stream and Direct Play enabled ofcourse.
So this behaviour did not make sense to me, so I canceled the stream and tried to play the same file again. This time the same file suddenly played correctly and was Direct playing the HEVC video, but the audio was transcoding.
This makes no sense. Why would the same file play correctly the second time you play it?
The whole “HEVC + unsopported audio format” use case on the Samsung TV Plex app seems very unstable at the moment
