DS1019+ unable to transcode 1080p

Plex Media Server NAS & Devices
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Server Version#: 1.16.5.1552 (Syno DS1019+, regular Plex install from the regular repository)
Player Version#: 7.21.0.12323 (Nvidia Shield TV)

Hi, I’m running Plex on a NAS supposed to transcode 4K to 1080p. However, all the files I’ve tried just fail to play smoothly (Plex warns about a too slow server). I’m first surprised that the Plex Server wants to transcode, while the reader is a Nvidia Shield TV, perfectly able to read many things. And in the worst case, I would have hoped that the Syno DS1019+ was able to transcode a 1080p file, which appears not to be the case in my configuration.

I’ve tried to check if there is something fancy with the files I’ve tried. They are all sub-6000kbps H264 - MPEG -4 AVC (part 10) (avc1), 1080p@23.97, 5592kbps with subtitles : VLC indicates “text subtitles with various tags (subt)”.

I’ve tried by playing the originals or by converting automatically.

The server and the shield are pluged on the same gigabit switch. The CPU usage raises from 50-60% to a 80% max. It doesn’t need to go as high a 100% to fail.

Yes, I’ve ticked te HW acceleration box, and it fails even with the “Hyper fast” x264 setting.

1 Like
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Check the Plex client settings on the Shield.

Video Quality
  Adjust Automatically = Off   (On forces a video transcode)
  Home Streaming = Maximum
  Remote Streaming = Maximum
  Play Smaller Videos = On

Video
  Burn Subtitles = Automatic
  Display Information = On  (needed for next step)

Advanced
  Passthrough = HDMI  (Off may force an audio transcode)

Play one of the problematic videos with subtitles disabled. During playback, pull up on-screen controls (tap bottom of ring on remote, pause video, etc). What does it show in the upper left corner of the screen for both audio & video? Direct Play / Direct Stream / Transoding. If transcoding, it should provide a reason.

Please attach Plex XML for the same video. Note that forum does not accept .xml attachments, so change to .txt or zip it before attaching.

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Thanks for the reply. The only different setting on the Shield was the passthrough thing, so I’ve changed it, and tried with one of the files.

The playback is smooth and it says:

  • Player: ExoPlayerv2
  • Video: Direct
  • Audio: Transcode
  • Size: 1920x1080
  • Transcode reason: E-AC3 audio is not supported by the device

I’ve attached the XML file of the corresponding video file : 6892.txt (3.4 KB)

As soon as I turn subtitles ON, then the playback is not smooth anymore and:

  • Player: ExoPlayerv2
  • Video: Transcode (HW)
  • Audio: Transcode
  • Size: 1920x1080
  • Transcode reason: E-AC3 audio is not supported by the device

Before buying the DS1090+, I’ve read user reports (on this forum in particular) stating that trascoding was OK with subtitles on iff the subtiles are text srt. On this particular file, I think they are. If transcoding was impossible with any subtitle, then I would not have bought a 1090+ at all.

EDIT : I’ve just given Emby a try, and it works flawlessly on the exact same files, with the same hardware (DS1019+ and Shield). I’d prefer to continue with Plex, however, beeing a long time user and my familly beeing used to it.

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Thanks for the info.

The device to which the Shield is attached does not support EAC3 audio, so PMS is transcoding the audio stream.

With Android TV devices, if the audio is transcoding and you enable any type of subtitles, the video will also transcode, so Plex can burn the subtitles into the video stream. Plex does this to keep the video, audio, & subtitles in sync with each other.

Burning subtitles forces a part of the transcode to happen on the CPU. That is why you’re seeing 50% - 80% CPU utilization.

If you look at the Dashboard during playback, it will show you to which format the audio is being transcoded (Plex Web -> Activity -> Dashboard).

Other than not enabling subtitles I am not aware of a workaround for this issue. You could attach the Shield to a TV/receiver/soundbar/etc that supports EAC3 audio, but that obviously involves greater expense.

Check the manual for the device to which the Shield is attached. See if you can find what audio formats are supported. You can expect the same behavior when playing a video with any unsupported audio format.

I’ve never used Emby, so cannot comment on how it handles things.

Wish I had better news.

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Thanks. Bad news but not beeing english native, I’m afraid that there is a misunderstanding and that I’m lost in translation:

  • The Shield hosts the player only (formerly I had the PMS on it as well, but I’ve been experiencing so many issues with the server and player on the same device, that I gave up)
  • The PMS is hosted by my Synology DS1019+, supposed to transcode 4K->2K with text subtitles

And EAC3 is ot an issue since it plays smoothly with subtitles off, transcoding not impacting CPU usage by more than 20%. It seems to fail when I add subtitles (text srt subtitles, I think, which are supposed to work). So it seems that subs are the cause, and disabling them is not an option to me.

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It was set to “Auto”. So I’ve set the option to “Image formats only”, without success ;-( The more it goes, the more I beleive that sadly, the DS1019+/Shield combination will accomodate Emby better.

My guess is that the Shield Plex client is actually the issue. I’ve often find that the client actually works better even on a cheap Mi Box than on my expensive Nvidia device.

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