Plex Transcoder uses a lot of resources

Plex Media Server NAS & Devices
1

Hello,

I noticed, that after adding any new movie to library Plex starts a job:
/volume1/@appstore/Plex Media Server/Plex Transcoder -codec:v hevc -i /volume2/video/movie/…
Which uses a lot of resources.
Why it needs to convert it?
How I can control it (allow to transcode or not, or to set what has to be transcoded and what not…)?
I am using Plex server 1.10.1.4602 on Synology DS415Play.

2

What format is the movie encoded in??
Looks like h265 4k??

That is probably why.

try
mp4 / h265 / ac3

3

Plex file info says: Codec H264
And it is not 4K as it is:
Video Resolution 576p
Duration 1:51:38
Bitrate 2797 kbps
Width 1232
Height 516

4

But main question why it is converting at all? What logic is behind it?
And how to control/configure it?

6

What is the problem with the transcoder at all? In many threads or forums is written that its problematic with many video types:
E.g. this one

Video Resolution SD
Dauer 43:32
Bitrate 2096 kbps
Width 720
Height 400
Aspect Ratio 1.78
Container AVI
Video Frame Rate PAL
Video Profile advanced simple

Container AVI
Video Profile advanced simple

Codec MPEG4
Bitrate 1442 kbps
Bit Depth 8
Chroma Subsampling 4:2:0
Frame Rate 25 fps
Height 400
Level 5
Profile advanced simple
Ref Frames 1
Width 720

Why does it use that much system ressources?

7

The simple answer?

Other than the big Xeon based models, Synology is infamous for using processors which ONLY serve the NAS functionality. They don’t give us the ‘extra head room’ to add things like PMS & transcoding. They think of one thing: “Does it work as the NAS it is marketed as?”

9

When you attempt to play a file on a Plex client that is not compatible with that client the file must be transcoded. The file cannot play on that client any other way.

I could understand that, but it starts now after adding any file. Even if it is H264. Even if it was not played at all.

So why Plex starts to convert any video which just added…
And really, you are sure, that it can not be configurable (to change when and what should be converted)?

10

If I may jump in?

Everyone is discussing the problem. How about we take an example or two, from anyone who cares to contribute, and show why it’s being transcoded?

To do this, what I will need is:

  1. The Media Info (or better View XML output of the movie being played)
  2. The player make/model being played on and any non-default player settings
  3. The log files (Debug logs, not Verbose logs), collected after playing for 30 seconds, from Settings - Server - Help - Download Logs (the ZIP file)

With this, I can walk through the decision process and show how PMS came to the decision it did.
Next we can see the impact on the processor and why.
Lastly, knowing the player and the source material, we can determine how to make it better. (DirectPlay is always the ideal solution)

12

Would the fact that the file is PAL trigger transcoding???

14

Still here is something not right, facts are:

  1. I am using this Synology with Plex for 3 years, and I was downloading a lot of movies - never saw such load spikes (so never checked is it transcoding something or not).
  2. Now, just after adding video and rescan library it start transcoding task with a lot of resources. So something changed…
  3. It transcodes even H264 videos - why?
  4. Plex now starts to transcode only after adding video and updating library (without starting to play!). It also was different before.

So it looks something wrong now…

16

trumpy81 - clearly.
You wrote in general that
“Transcoding is used ONLY when a file cannot be played by your Plex client device. Then Plex will attempt to transcode the file.” - But I try to explain that not it starts to convert WITHOUT starting to play, just after adding to library.
Also, I play on TV which totally supports H264, but it still converts - Why?

And try to tell that Plex is acting differently if compared to with several years before. Also, to know reason would be nice.