Plex not using Intel Quick Sync for 4K HEVC content

I’ve been a Plex user for several years. The last few years, I’ve been running my Plex server on an old AMD FX-6300 system and it’s been doing good for my needs until recently. It had troubles transcoding 4K HEVC streams to the point where they were unplayable. I read up on hardware transcoding using Intel Quick Sync and since I have Plex pass, I decided to buy new hardware for my server. I put together an i7-10700k system and installed Ubuntu Server 20.04.2 LTS and the latest version of Plex media server on it. I made sure hardware transcoding is enabled, but it looks like 4K HEVC streams are still using the software transcoder, even though this processor supports transcoding it (the dashboard isn’t showing the (hw) tag on the stream). Looking at htop shows about 50% cpu utilization and intel_gpu_top shows no gpu usage when transcoding 4K HEVC to 720p. When transcoding a 1080p file to 720p, cpu utilization is basically nothing and intel_gpu_top shows gpu utilization. File info shows the video as HEVC 5.1 Main 10. I do have the dependencies for tone mapping installed (Beignet) and I reinstalled the plexmediaserver package after installing the dependencies. Is there something I’m missing? Thanks in advance.

Server Version#: 1.21.4.4079
Player Version#: 7.13 on iOS

2021-03-01 08_07_01-Plex - Brave

Plex_Transcode_logs.txt (283.6 KB)

I found the above quote, and it’s possible this applies here since you’re transcoding an HDR title.

My server can transcode 4k no problem (i7-10700k). I’m just wondering why it’s using the software transcoder instead of the Quick Sync hardware transcoder.

Transcoder log file isn’t enough data.

Need the “Plex Media Server.log” (at minimum) , DEBUG logging , VERBOSE OFF,

which captures the start of playback, 20 seconds of playback, and termination.
(this is why the full ZIP is easier).

We need the “MDE” , hardware probe, and Transcoder invocation.

That’s just what I named the file. I got it from the console tab in the UI with debug logging and verbose off. I’ll PM you a log bundle.

@CaptainRedHat

It’s attempting the HW transcode but falling back to SW

May I see the XML for a few of these which fail?

Also, you do have the Beignet and OpenCL libraries installed for HEVC HDR transcoding?

@ChuckPa

Yeah I do have both of those libraries installed. I also reinstalled the plexmediaserver package after installing those packages to make sure it picked up that configuration. I’ve attached XML’s from 3 movies that fall back to software transcoding.


4k_HEVC_XMLs.zip (57.4 KB)

@CaptainRedHat

Try something for me?

  1. Create a new temporary library of type Home Videos.
  2. In that library, place a remuxed version of these movies.
  3. When you remux them, Remove the PGS subtitles.
  4. PGS subtitles (or any burned in) will suppress HW transcoding.

@ChuckPa

I used MKVToolNix to remove the Subtitle tracks from each of those movies, but it’s still not using hardware transcoding with those files. I verified that there are no subtitle tracks available using VLC.

Good. Let’s construct a careful log for the transcoder team.
(They said it should be supported without issue).

  1. Please report status of Settings - Server - Transcoder
    a. HW transcoding settings
    b. HEVC HDR settings.

  2. Kernel version and Distro (Centos 7 or 8 ?)

  3. With DEBUG logging on, VERBOSE logging off, (restart PMS if possible)

  4. Play for 1 minute

  5. Stop Playback

  6. Let logs flush (20 seconds)

  7. Download the Logs ZIP file

  8. Attach please with info about your settings.

@ChuckPa

  1. Here are my HW Transcoding settings:

  2. Ubuntu 20.04.2 LTS (GNU/Linux 5.4.0-66-generic x86_64)

  3. Here’s the new log bundle
    Plex Media Server Logs_2021-03-01_20-59-08.zip (4.4 MB)

Thank you… This is excellent.

May I have a sample of the file ?

If you can snip 15 seconds worth using FFMPEG and then posting a link, that would be great. ( Don’t think it would fit here otherwise )

Here you go!

@CaptainRedHat

Your video sample did not fully engage hardware for me either. (i7-8809g).
It should have engaged the HEVC HW decode – It did not.

Please take this file, place it in your Samples/Other Videos area. and play it.
This file provides me full HW decode, HW encode, and HDR.

This is a 2 minute sample file

I played both of the files uploaded by you two outside of Plex (using MPC-HC with madVR), and while your file is playing as a proper HEVC file, the OP’s file is not. I don’t know if that’s due to a difference in the way you shortened the file, but if it’s not then that would leave me to believe there was an issue with the rip. Feel free to correct me if I am wrong as I am relatively new to all of this.

@IFireflyl

I believe there is an issue with the @CaptainRedHat 's rip.

The results of playing my rip will also let us know if there is a deeper problem with the -10xxx CPU (which there should not be)

1 Like

@ChuckPa I tried playing your sample file and it’s still not hardware transcoding.

2021-03-01 16_43_32-Plex - Brave

Logs ?

We know the file is good

Also, did you try transcoding to something more than 2 Mbps 720p ?
I wonder if that’s not part of the problem

Play it LOCAL, in the browser, 10 Mbps 1080p

@ChuckPa Sorry man, it’s been a long day lol. Logs attached. I followed the same procedure as before, except local in the browser 10 Mbps 1080p.

Plex Media Server Logs_2021-03-02_04-49-10.zip (4.1 MB)

Thank you for doing that.

The same error I saw before was repeated.

I will forward this to the engineer I’m working with and ask what additional information is needed if any.