Only cpu transcoding while using Plex for windows

Plex Players Desktop Players
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1

Server Version#: 1.20.1.3252
Player Version#: Plex for Windows 1.18.0.1392-cf94f6a1

Hi there,

Just found a weird thing.

The same file, when playback with Plex for windows, server can only transcode it by CPU, but when I changed android app or web app to play it, server HW transcoding works well.

Is there any clue to solve it?

Thanks.

2

Normally, this player doesn’t require any transcoding at all.
So please take a closer look at what was actually transcoded. Video, or only Audio, or both? Hardware trancoding is only available for video transcoding.

In the web app, under the Activity icon - Dashboard, then enable the detail view

3

Hi there,

Thanks for your reply, let me state more detail about this.

I am now using plex for windows to play this video remotely, and manually set quality to 720P 4MP to force transcoding working. And it works like following:

1.PNG
1.PNG925×540 122 KB

and cpu gpu status looks like this:

1-1
1-1884×889 47.9 KB

which is clearly transcoding by CPU.

And then, I found this, if I disable HW encode as following:

2
2891×443 425 KB

HW transcoding works, but it seems CPU also involved.:

2-1
2-1893×560 205 KB

2-2
2-2887×814 62.8 KB

However, for the same file, if I use android app to play it at 720P 4M, HW transcoding work fine and will not involve CPU. (GPU works at 50% and CPU works at a very low level.)

Video info:
Codec H264
bitrate 11197 kbps
Bit Depth 8
Chroma Location left
Chroma Subsampling 4:2:0
Coded Height 816
Coded Width 1920
Frame Rate 23.976 fps
Height 804
profile high
Ref Frames 5
Scan Type progressive
Width 1920
Display Title 1080p (H.264)
Extended Display Title 1080p (H.264)

Codec AC3
bitrate 640 kbps
English
Audio Channel Layout 5.1(side)
Sampling Rate 48000 Hz
Display Title English (AC3 5.1)

CPU: i5-8250u GPU: UHD620
drive:26.20.100.7000 (didn’t use recent drive to avoid random crash when using HW transcoding)

Let me know if you know more info.

4

Does this behaviour change, if you disable the subtitles?

5

unfortunately, it is still the same, 100% CPU consumption.

3
3886×564 207 KB

and here is what it looks like when play with android device, subtitle on, and HW decode& encode both on:

3-1
3-1890×562 459 KB

3-2
3-2880×889 44.6 KB

Thank you for the prompt reply.

6
  1. activate debug logging (not ‘verbose’!)
  2. quit Plex Server
  3. wait 1 minute
  4. start Plex Server
  5. wait 2 minutes
  6. Play the movie for about 1 minute
  7. wait 3 minutes
  8. fetch log files and attach them here
7

WOW, it seems REBOOT magic works :wink:, now it begins to HW transcode:

4
4895×559 214 KB

and here is the log file:
Plex Media Server Logs_2020-09-15_16-36-35.zip (587.7 KB)

Thank you.

8

If it is now working, there are no useful informations in the log files, about why it didn’t work before. :wink:

Happy plexing!

1 Like
9

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