Server Version#: 1.19.5.3112
Hardware: Synology DS920
Player Version#: 5.0.13
WebOS Version#: 4.8.15
TV#: LG UM7510PLA 4K
File in question - Audio sync issue
Source…: Bluray
Runtime…: 3h 16mn
Size…: 17.2 GB
Audio Codec…: DTS
Audio Bitrate: ~1 510 Kbps
Video Bitrate: ~12.5 Mbps
Video Codec…: AVC
Resolution…: 1920 x 784 pixels
Framerate…: 23.976 fps
Container…: Matroska
So, I am having audio skew issues with the more resent Plex client or server updates on my LG TV. This is a resent issue, only having had the TV 3-4 months, did not have this issue previously.
I noticed it is only when I have direct streaming enabled. Once I disable direct stream the video now transcodes and the audio switches to AAC or some similar audio format. The original video could be DTS, DTS-HD or Atos it does not seem to matter. I dont have this issue with any of the 4K content.
This is a new issue and I am wondering if it is specific to one of the Plex server updates. I do not have any issues with Windows Plex App (DP), Plex Web App (DP), Mobile Phone, Tablets, or direct play from Media Player Classic etc. so it’s not the video itself. I do not want to scale down the audio as I have good AV receiver and speakers (not an option), what can I do to help troubleshoot this so it can get fixed?
4K file that works fine:
Format : Matroska
Format version : Version 4
File size : 40.3 GiB
Duration : 2 h 1 min
Overall bit rate mode : Variable
Overall bit rate : 47.3 Mb/s
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@High
HDR format : SMPTE ST 2094 App 4, Version 1, HDR10+ Profile A compatible
Codec ID : V_MPEGH/ISO/HEVC
Duration : 2 h 1 min
Bit rate : 41.4 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0 (Type 2)
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.208
Stream size : 35.2 GiB (87%)
Language : English
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : PQ
Matrix coefficients : BT.2020 non-constant
Mastering display color pri : Display P3
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
Maximum Content Light Level : 233 cd/m2
Maximum Frame-Average Light : 63 cd/m2
Audio #1
ID : 2
Format : MLP FBA 16-ch
Format/Info : Meridian Lossless Packing FBA with 16-channel presentation
Commercial name : Dolby TrueHD with Dolby Atmos
Codec ID : A_TRUEHD
Duration : 2 h 1 min
Bit rate mode : Variable
Bit rate : 5 013 kb/s
Channel(s) : 8 channels
Channel layout : L R C LFE Ls Rs Lb Rb
Sampling rate : 48.0 kHz
Frame rate : 1 200.000 FPS (40 SPF)
Compression mode : Lossless
Stream size : 4.30 GiB (11%)
Language : English
Default : Yes
Forced : No
Number of dynamic objects : 13
Bed channel count : 1 channel
Bed channel configuration : LFE
I haven’t got any technical details to hand, but I’ve also noticed sync issues with the more recent PLEX app for LG TV. My TV is the 7400 - a basic 2019 model.
Sometimes the issue can be corrected by exiting the video and resuming, sometimes I need to exit the app and go back in again.
I watched a movie tonight (1080p, DTS soundtrack) and it started off way out of sync (about a second) . A number of restarts later and it got to an acceptable level, but no matter what I tried, the video was still about 50ms ahead of the audio streaming to my AVAmp by ARC. Testing the file on PC it’s perfectly in sync.
I’m sure these sync issues seem more prevalent with DTS tracks, and that Ididn’t have any sync issues for the first few months I was using the app.
OK I’ve had a bit more of a play with this tonight.
Firstly, I have identified that unticking the DTS (DCA) compatibility box in Plex on the TV cures the problem, but it means the audio is being converted to DD, which I really want to avoid.
Information I have at hand:
TV - LG UM7400PLB (49")
Latest software (04.80.15)
Server
Synology DS218j
PLEX App
Client version 5.1.2
Platform version 4.8.0
Av Amp
Yamaha RXA-680
Updated software this evening - made no difference.
This is frustrating as it was working perfectly when I first installed plex. Presumably either a plex or TV update along the way has screwed something up.
Any suggestions gratefully received!
EDIT TO ADD - I tried the TVs built in media player via DLNA and it plays back the same files without any issues. I’m pretty certain this is a Plex issue.
Server Version#: 1.19.5.3112
Hardware: Synology DS920
Player Version#: 5.0.13
WebOS Version#: 4.8.15
TV#: LG UM7510PLA 4K
Format : Matroska
Format version : Version 4
File size : 24.6 GiB
Duration : 1 h 45 min
Overall bit rate : 33.6 Mb/s
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@High
HDR format : SMPTE ST 2086, HDR10 compatible
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1 h 45 min
Bit rate : 29.7 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Bit depth : 10 bits
Audio
ID : 2
Format : DTS XLL
Format/Info : Digital Theater Systems
Commercial name : DTS-HD Master Audio
Codec ID : A_DTS
Duration : 1 h 45 min
Bit rate mode : Variable
Bit rate : 3 839 kb/s
Channel(s) : 6 channels
Compression mode : Lossless
Stream size : 2.82 GiB (11%)
Language : English
So, get this, watching a 4K video tonight and the Mrs says look the audio is squewed. She was not wrong, but if she is spotting it, it’s becoming a joke now! Its normally me that spots it first.
So here is the clincher, if I disable direct stream and it works fine (LG Tv see image), but guess what, it’s still direct streams and but it’s now perfectly in sync… I do not get it!?!
@plex could some be so kind as to make some sort of effort here? I do not think I’m the only person that has this issue. I really had to rain myself in here not lose my s%&t with the lack of response from you guys at @plex support!
@ahiyahiya@emilybersin sorry to @ you both (got your names form the release mails), but I dont know what else to do with this issue… Im not getting any love from Plex.
I have a brand new LG TV and am seeing the same type of thing. My older LG TV had not been having the issues. However, I’m noticing it even in low res 720p rips I made on my wife’s exercise dvds. Simple stereo audio. When she pauses the videos, then resumes the audio seems to sync much better. I’m connected by eARC to my soundbar.
#plex I know I’m not a pass holder, but the other two reporting this issue are.
Is it too much to ask that you acknowledge this issue and commit to trying to fix it? I don’t expect you to give timescales or anything - just knowing that it being worked on would be a start
The WebOS client is shocking,tho I find most of the apps on LG awful too.
I find audio sync issues intermittently with regular broadcast TV. If I turn it off and on again it works. This doesn’t fix plex audio tho… I resorted to buying a fire TV stick and using the Amazon plex client instead.
WebOS plex client definitely needs some developer love.
@dpeckham yes I notice that on some aac stereo tracks. I select the file to play, it says buffering but then starts playing out of sync. Pause and resume and it’s fine. That is with EARC too.
However with dts it doesn’t fix the issue - the only thing I can do with those is transcode to DD, which whilst making it work, is creating unnecessary conversions and a loss in quality.
Yapp, I second that, same thing for me. One of the last updates has screwed this up. @Plex can one of have the decency to reply here, it is getting ridiculous!
That’s not true. The last update was 20 days ago, as can be read here: Plex for webOS (2+ UHD Televisions)
Even if you opted out of the public preview the last update was on July 30th.
Maybe you checked the date in the LG content store? You should ignore this. This is only the “launcher app” which gets updated very rarely. The “actual” app is updated without the LG content store noticing it.
Btw, another hint: Mentioning the @Plex user won’t bring any attention to this topic. This user is not active/used.
