Player Version#: Plex LG 5.86.4
Server Version#: 1.40.4.8679
On the LG CX PLEX App when direct playing 4K HDR/ Dovi files that have DTS / TrueHD audio that need transcoding the video becomes corrupted. Switching to another audio track fixes the issue but some of my files only have a DTS / True HD audio track. I included a picture of what the video looks like when it becomes corrupted with a small box appearing in the upper left hand corner of the screen. I realize that LG CX TV’s do not support DTS / True HD passthrough and that is why I have DTS audio turned off in the LG Plex app settings. The Issue appears to be that since it needs to transcode the audio down to AC3 / AAC it also is transcoding the video and corrupting it. Is there a fix or is the plex team aware of and working on the issue?
On the section “Hardware Transcoding Device”, Try changing it from “Auto” to the actual HW device your using in your PC to HW transcode. I had a similar issue with HW transcoding when using a gaming PC with a RTX 4060 before moving to M2 Mac. Once I changed “Hardware Transcoding Device” from “Auto” to “RTX 4060”, HW transcoding started working again.
It does appear to be a known issue with the lg Plex app and dts Audio. Unfortunately for some of the 4K files I have the DTS 7.1 MA-HD / TrueHD are the only audio tracks. I wish it was just one file but it’s at least 5-6 of my 4K HDR files and I have 400 4k movies so I assume many more
Ok I changed it! I have a RTX 3080 so hopefully it will fix the issue. Overall I’ve never had any problems with video transcoding on any other devices just my TV’s LG CX Plex app.
I only suggested this change because I had a similar issue where Plex would sometimes fallback to a Software transcode for the video when trying to transcode DTS/TrueHD audio, Even though I had HW more than capable of HW transcoding the video. Obviously the audio will still be done in SW, But with the HW taking most of the heavy 4k lifting, Hopefully this might solve the issue for you.
Switching it from Auto to my 3080 did not fix the issue. I made sure to restart my server. I’ve found a couple other thread topics of people who have had this same problem. Hopefully Plex is aware of it and is working toward a fix
I have Earc soundbar but that doesnt matter since LG doesn’t support passthrough for dts. I have a roku and there isnt an issue with that and watch plex with an htpc gaming pc I have setup as well. But I still think they should fix the issue with the LG app if they are aware of it
I think Plex would immediately support passthrough if LG allowed it. I also have passthrough via the Nvidia Shield. With the Fire TV 4K, I have no problem with TrueHD Atmos and DTS:X via the Plex app, even on my 1080p TV. Are there other players, such as Kodi, VLC or MX Player Pro for the LG? Do they have the same problem? I still suspect that it’s not a Plex error, but LG’s problem.
The Plex app on my 1080 Samsung TV plays the movie but remains silent when I want to play 4K with DTS:X.
My bad I meant lg doesn’t support passthrough I edited my comment to correct that. Plex still should be able to solve the video becoming corrupted due to transcoding that is a seperate issue from lg dts support
I have the same issue on my LG C2. However to me it seems that the issue is not with transcoding video, but with Bandwidth. The ethernet port on the LG tvs is only 100MB/s. This is easily maxed out with 4k Remux files. When I try to play any file where the bandwidth is to big for my TV, I get the exact same image as you do in your screenshot. This also happens on wifi when it is too slow for the large bandwidth of the file.
This is easy to test. Play a file which does this for you, then change the quality down to transcode 1080p. When I do this, every time it plays fine which shows it is not the transcoding corrupting the file.
If I rencode my file with the same settings down to a lower bitrate, it plays fine.
Check on your system and see if it is the bandwidth of the large video+audio streams which is causing you the same issue as well.
The same high bit rate files that create the video corruption when I have to transcode the audio down play fine if I check the box back on for DTS and direct play them. But then I have no audio and silent movies. I will try ethernet but I do not think it is a solution. The problem is plex is transcoding the video because of the audio when it shouldn’t. They need to fix this
