I am playing Planet Earth II in this format: 2160p HDR HEVC DTS-HD MA.7.1-SYS.mkv to my LG C2. Why can’t the TV Plex app just have the appropriate codecs and read the file directly like my PC video player which is just 99mb of size and I have never had an audio/video file that it can not play directly including this one? Now my laptop CPU is at 100% transcoding both video and audio of this 96.6gb video file which will take some hours.
Likely the bitrate
Your TV is only capable of 100mbps
At 96gb the bitrate is going to spike well above 100mbps
You can recreate the transcode and post your server logs if you want to know the exact reason
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Plex Media Server.log (1.1 MB)
Plex Transcoder Statistics.log (12.3 KB)
Are these the important logs that you need?
You are burning subtitles
You need a very strong CPU to burn subtitles into a 4k HDR video. Laptops, and most NAS devices will fail when this happens
Disable the subtitles and try to play the file again.
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Yes you were right, turning off “burn subtitles” inside TV app did removed the transcoding of video and dramatically reduced CPU load, the audio is still getting transcoded, it’s 7.1, is this because I don’t have 7.1 sound system connected to TV?
But when I try to play same video in Chrome browser even thought I changed it at Settings > Player > Burn Subtitles(Only image formats) it still transcodes video, why it doesn’t use the appropriate codecs like my video player program(it never has to burn in anything or transcode)?
Fair chance the browser itself doesn’t support it.
Overall browsers are a poor playback option.
They all support different codecs and formats and are subject to the same kind of breakage anything is, due to updates and incompatibility like this
I suggest you try Plex for Windows or Mac. I don’t know if it will work for that specific file, but overall you have a much better chance of direct playing most media
https://www.plex.tv/media-server-downloads/#plex-app
I’m not sure why the audio is transcoding. Your logs give a somewhat vague reason
MDE: Cannot direct stream audio stream due to profile or setting limitations
I would think Plex would just downmix the 7.1 into stereo without a transcode like it does for something like Dolby 5.1 but I just don’t know
Someone with more knowledge about how Plex handles these more advanced types of audio formats will have to answer that one
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To add to @JaysPlex’s comments…
Short Answer:
- When using the Plex LG app, do not enable subtitles when the audio is DTS or TrueHD.
- If you want subtitles, use a streaming device such as a Nvidia Shield Pro or Amazon FireStick 4K / 4K Max.
Long Answer:
The LG C2 does not support DTS or TrueHD audio (see specs at LG). Therefore, when you play media with either audio type, it will be transcoded by Plex Media Server to a compatible format.
Transcoding audio is not compute intensive and not a problem unless using a very low power CPU.
However, subtitles throw a big wrench in the works.
With the Plex for LG app, if the media is direct streaming, such as when audio is transcoding, enabling any form of subtitle results in a video transcode. Furthermore, Plex must burn the subtitles into the video (add them to the video image instead of streaming separately). Subtitle burning uses the CPU, even when using hardware accelerated transcoding (which requires a Plex Pass).
Having a Plex Pass would not help much, since subtitle burning uses the CPU. The process is very compute intensive and, for 4K HDR media, not possible with most CPUs.
Solution
Use a 3rd party tool such as XMedia Recode to transcode the audio to a supported format (AC3/EAC3) before loading the file into Plex. Generally not recommended as it is an administrative pain.
A better solution is to use a Plex client that supports DTS & TrueHD audio and does not require video transcoding when subtitles are enabled.
Many people use the Nvidia Shield Pro, which runs the Plex Android TV client. The Shield will direct stream PGS & SRT subtitles even if the audio is transcoding, so video transcoding is not required. The Shield will also passthrough (bitstream) DTS/-HD/:X and TrueHD + Atmos audio to your sound system if it supports those formats.
If you do not care about audio passthrough, then you can look at other clients such as the Amazon FireSticks. They also use the Plex Android TV client. They do not passthrough lossless TrueHD or DTS audio, but that is not a problem if your audio system does not need those formats (they are transcoded/decoded to a compatible format). They also cost less than a Shield Pro (~$60 USD vs ~$200 USD).
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This is getting too complicated and demanding fast. I downloaded Plex so it can be an easy set and forget. I was initially planning to just use Windows multimedia server but it didn’t support subtitle files at all so it didn’t quite work. Thanks for the detailed answer I have no more questions.
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