Plex Slow to start playback

Plex Media Server
,
1

Server Version#: Version 1.21.3.4021
Player Version#: Web player 4.22.3

Mediainfo

General
Unique ID : 55523152406881070086163578064538892057 (0x29C55EC44B6EFF16D5F4152A2A3AF719)
Complete name : test.mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 3.00 GiB
Duration : 43 min 3 s
Overall bit rate : 9 987 kb/s
Encoded date : UTC 2021-02-22 08:03:17
Writing application : mkvmerge v52.0.0 (‘Secret For The Mad’) 64-bit
Writing library : libebml v1.4.1 + libmatroska v1.6.2

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 43 min 3 s
Bit rate mode : Constant
Bit rate : 9 345 kb/s
Nominal bit rate : 10 000 kb/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) : 0.188
Stream size : 2.81 GiB (94%)
Language : English
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio
ID : 2
Format : E-AC-3
Format/Info : Enhanced Audio Coding 3
Codec ID : A_EAC3
Duration : 43 min 3 s
Bit rate mode : Constant
Bit rate : 640 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 187.500 FPS (256 SPF)
Compression mode : Lossy
Stream size : 197 MiB (6%)
Language : English
Service kind : Complete Main
Default : Yes
Forced : No

Text
ID : 3
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Duration : 42 min 58 s
Bit rate : 112 b/s
Count of elements : 1168
Stream size : 35.5 KiB (0%)
Title : English
Language : English
Default : No
Forced : No

Ok, so the latest version of plex is taking too long (more than 25-30 seconds) to start playback of some files, I have added mediainfo of one such file.
I have noticed that when plex starts the playback (spinning before the playback), it uses only 100% single core of all the available core. now this is not an when playing the same media file on a server with high clock speed (to be specific 4.9GHz), but when playing on a server with lots of core but lower clock speed (2.10GHz), This causes significant slowdown.

shot_210318_184143
shot_210318_1841431787×600 10.7 KB

Is there any way to fix this behavior? i.e. use all the available cores?

I have tested this on a random older version (1.19.5.3112-b23ab3896) and there is no such issue. playback start time is 5-9 seconds on average.

If you need more info, let me know.

Thanks.

2

Sorry, but none of what you’ve posted there is of any use in debugging.

The newer versions (e.g. current) have HDR tone mapping support.
HDR tone mapping is enabled by default.
If your CPU is not HW-capable, it will use software – which makes starting playback slow.

May I see the DEBUG log files which capture the start of a playback so I may diagnose? (current PMS version would be great)

3

Should I only include this “/Library/Application Support/Plex Media Server/Logs/Plex Media Server.log” log?

The CPU is - E5-2620 v4, it does not have any GPU, so no HW acceleration I guess.

4

Thanks. With that information, I definitely need the logs to see what’s happening.

5

Here you can find the log - Plex Media Server.log - Pastebin.com
I think the playback starts at line number 780.

6

Is it a safe assumption that if you don’t have 4K media, you can turn HDR tone mapping off?

7

Where I can find this option ? There is no such option in my transcoder setting as mention here.

8

Under settings / transcoder

9

Hi, have you checked yet? I am trying to pass -movflags +faststart to the transcoder, but it seems there is no way to do this.
Let me know if you need any more test result/log files. :slight_smile:

10

@WhyPlexIsSoBuggy

That log doesn’t show me active playback.

Please do the following:

  1. Start Playback
  2. Wait 20 seconds
  3. Stop Playback
  4. Wait 20 seconds
  5. Download the Logs ZIP file

If you need a PM to send it to me, please let me know.
I prefer as they are printed. Sanitized often loses info.

11

Yeap, I stopped playback as soon as it started.
I would like to drop a PM with logs.

Thanks

12

Hello,

How can I PM to you?

13

Sorry to bump again, but is it possible to send you a PM? I can mail you as well, if you can give me some temporary email.

14

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