@chrisallen I sent you the larger sample and 1.5.2 logs. I also did some broader tests. The issue only happens on TrueHD, and the number of channels doesn’t seem to make a difference. Neither does Atmos. DTS-MA titles are fine.
Any new information? Is this something you’re able to reproduce?
SOOO Glad I found this thread. I was pulling my hair out. I figured my CPU was choking on TRUEHD 7.1 movies (like the new movie SING) because anytime the transcoder got involved, my CPU would spike at 100% and my audio would not be in sync with the video. What made it worse was, my friend has a similar set-up to me but his worked perfectly. The only difference is he has a slightly more powerful CPU and his would top out around 80-90% utilization while I was at 100% utilization. I was literally building an online shopping cart because I assumed that was it. Come to find out, my friend is only updated on the “Public” channel, and is at 1.4.X on his PMS. I’m on the latest Plex Pass version. We did think it was odd that I had the EasyAudioEncoder.exe process and he didn’t while we were comparing system utilization. Makes sense now.
I have a Core i5-4690S, 8GB of RAM, FWIW.
Thanks!
@drshaw which OS are you using Plex Media server on?
Also if your friend upgrades to 1.5.2 PMS do they see the same issues you are with TrueHD.
This is a high priority issue for us, but we are struggling to reproduce it, even with samples from users here. We are trying to find a common theme between reports.
Any detailed info, logs etc would be super helpful
I am on Windows 8.1 and I haven’t run Windows Update since January 2015 :o – we don’t have any other background tasks or programs running… it’s basically a dedicated HTPC in both scenarios.
My friend is on Windows 10 (upgraded from Windows 7, not even a fresh format) but doesn’t want to upgrade his Plex Media Server because his is working right now (he even owns a Plex Pass just didn’t know about that Update Channel setting).
I can confirm it happens on most (maybe all) Dolby TRUEHD 7.1 movies that need to be transcoded. Blu-Ray MKV rips from SING, Fantastic Beats and Hacksaw Ridge are confirmed.
Happens if I play on my iphone client, plex for web via Chrome, or Roku 3 (again, anytime they need to be transcoded). I don’t think it happens when I direct play things without transcoding, I can verify tonight.
When the problem is happening, the video is about 1 second ahead of the audio.
@chrisallen Here’s something to consider. I’m seeing that, in order to play back on the Roku 3, the EasyAudioEncoder folders contain temporary files for Convert to WAV and Convert to DD, and the samples are being written to disk as playback progresses. I have also noticed that when this happens I’m not running out of CPU overhead. If I have nothing else happening on the NAS it’ll play back at about 45% CPU, but the sync problem remains.
I was surprised to see that it had to store not only the intermediary WAV sample, but also the DD sample on disk, only to be muxed into the transcoded segment, which would be written again. That seems like a lot of disk activity for a process only taking up about 400k of memory (where doing that sort of buffering would make more sense).
It’s possible that some people aren’t seeing the issue because there’s fewer “hops” from TrueHD to their player’s preferred playback format.
Also, can you explain why the decoder is changing at all? It seemed to most people that the “truehd” decoder was working great. If I could, I’d switch back to using that.
I am having the exact same issue. I have a i7-6700k.
The issues i have are all with TrueHD like everyone else. New sing movie was off by 1-2 secs. Also had issue with Fantastic beasts and a movie that use to play fine “Nightmare before Christmas”. The issue would only happen on remote playback or any player that needed transcoding. Playing locally on PMP or Nvidia Shield had no issues.
What i found was that if i change the audio delay in MKVTookNix to a 1ms delay the audio plays just fine.
CPU usage has also been extremely high lately. Today i just noticed the EasyAudioEncoder that has not been there before and it is using 14+% of CPU. The program runs even when videos are in “Direct Play”
@NekkoStream when playing on the NVIDIA SHIELD is the TrueHd stream being transcoded?
Would you mind sharing your server with me so I can attempt to reproduce locally from your server.
Can anyone experiencing this issue please provide mediainfo output from the files you are seeing this with?
@chrisallen said:
Can anyone experiencing this issue please provide mediainfo output from the files you are seeing this with?
mediainfo output? How do we produce that?
@“matthew hitchens” https://mediaarea.net/en/MediaInfo/Download please download that, and open your media file in it. then switch to the “TEXT” view and copy paste the info here.
General
Unique ID : 323299379070622294003714693547908487573 (0xF339320D4BF2D8220DFF0906C6455995)
Complete name : /Volumes/video/movies/The Secret Life of Pets (2016)/The Secret Life of Pets (2016).mkv
Format : Matroska
Format version : Version 2
File size : 21.6 GiB
Duration : 1 h 26 min
Overall bit rate mode : Variable
Overall bit rate : 35.7 Mb/s
Movie name : The Secret Life of Pets
Encoded date : UTC 2017-01-27 22:58:06
Writing application : MakeMKV v1.10.4 darwin(x86-release)
Writing library : libmakemkv v1.10.4 (1.3.3/1.4.4) darwin(x86-release)
Original source medium : Blu-ray
Cover : Yes
Attachments : cover.jpg
Video
ID : 1
ID in the original source medium : 4113 (0x1011)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 26 min
Bit rate mode : Variable
Bit rate : 30.8 Mb/s
Maximum bit rate : 36.0 Mb/s
Width : 1 920 pixels
Height : 1 080 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
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.620
Stream size : 18.6 GiB (86%)
Language : English
Default : No
Forced : No
Audio
ID : 2
ID in the original source medium : 4352 (0x1100)
Format : TrueHD
Format profile : TrueHD+Atmos / TrueHD
Codec ID : A_TRUEHD
Duration : 1 h 26 min
Bit rate mode : Variable
Bit rate : 4 875 kb/s
Maximum bit rate : 7 452 kb/s
Channel(s) : Object Based / 8 channels
Channel positions : Object Based / Front: L C R, Side: L R, Back: L R, LFE
Sampling rate : / 48.0 kHz
Frame rate : 1 200.000 FPS (40 spf)
Bit depth : 24 bits
Compression mode : Lossless
Stream size : 2.94 GiB (14%)
Title : Surround 7.1
Language : English
Default : No
Forced : No
Text
ID : 3
ID in the original source medium : 4608 (0x1200)
Format : PGS
Codec ID : S_HDMV/PGS
Codec ID/Info : Picture based subtitle format used on BDs/HD-DVDs
Duration : 1 h 26 min
Bit rate : 44.5 kb/s
Count of elements : 3390
Stream size : 27.4 MiB (0%)
Language : English
Default : No
Forced : No
Menu
00:00:00.000 : en:Chapter 01
00:05:05.847 : en:Chapter 02
00:09:24.063 : en:Chapter 03
00:13:19.340 : en:Chapter 04
00:18:03.665 : en:Chapter 05
00:22:14.458 : en:Chapter 06
00:28:51.855 : en:Chapter 07
00:32:55.306 : en:Chapter 08
00:36:55.838 : en:Chapter 09
00:42:27.294 : en:Chapter 10
00:44:46.767 : en:Chapter 11
00:50:21.226 : en:Chapter 12
00:54:45.407 : en:Chapter 13
00:59:33.987 : en:Chapter 14
01:02:36.210 : en:Chapter 15
01:07:12.361 : en:Chapter 16
01:13:06.840 : en:Chapter 17
01:16:04.601 : en:Chapter 18
01:18:48.056 : en:Chapter 19
01:19:58.627 : en:Chapter 20
I can confirm I’m seeing this with several, but not all TrueHD tracks on 1.5.2, and iOS clients. Direct Play (and audio bitstream) to SHIELD TV is obviously fine. It doesn’t seem to be terribly dependent on client bitrate. I can repro on local wifi or remote limited to 4Mbps. I’m trying to gather more info from other clients. I’ve had two different models of Samsung TV watch a TrueHD movie, and they didn’t complain about sync (and it’s so bad I’m sure they would have complained). I’ll post back if I can find more details.
Oh, I should mention that I’m seeing it with both Atmos tracks I have, and am 50% on “regular” TrueHD tracks I’ve tried.
I have successfully reproduced the issue using a sample from @“Matthew Hitchens” (Thank you!)
One thing worth noting is that this was not reproducible on my Bluray remux version of The Secret Life of Pets (2016), but was able to the sample provided.
I have provided our transcoder team with the sample and steps to reproduce so that can start working on a fix. I will let you all know here when we have more info to share.
Thank you all for your help with tracking down samples and logs!
Another data point. I’m seeing it for a TrueHD movie when streaming to a local iPhone that it transcoded to AC3. Same movie streamed to a remote iPad it transcoded to AAC also saw it. So it’s not necessarily dependent on the target codec. I also thought that was odd… I’ve never noticed Plex use AAC for an iOS client. But maybe I just don’t pay enough attention 
I was starting to think I was going crazy. Dual Xeon with 24gb RAM and it couldn’t keep up with audio anymore? I’m so glad I found this thread. Please let us know what the transcode guys find and the ETA for a fix.
What program muxed people’s files? Anyone else using MakeMKV? I just learned that MakeMKV rolls it’s own MKV multiplexer (libmakemkv) instead of leveraging libavformat (which PLEX’s transcoder uses via ffmpeg). I’m going to try remuxing with ffmpeg and libavformat to see if there’s any difference. I also didn’t know that their libraries are OSS now. Here’s an archive of their latest release’s source tarball.
We are in the process of testing a fix that we are confident resolves this TrueHD audio sync issue. If all goes well, this will be included in the next PMS release.
@chrisallen This is great news! Thank you for your efforts.
For those that want a work-around for now, you can use @cayars script to convert your TrueHD mkvs to mp4s while the fix is being implemented. (which I’ll probably do to my entire library to make sure everything direct plays)
