Synology DS218play transcode problem with HEVC/H.265 files

Plex Media Server NAS & Devices
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Server Version#: 1.20.5.3600

Hello to all,

I’ve long been a loyal Plex user, and I’m here writing for the first time.
I recently bought a Synology DS218play NAS and immediately installed Plex on it. With h.264 files no problem, but with HEVC / h.265 files the transcoding doesn’t work well at all.

For example, when I try to start any HEVC video file (1080p no 4K) the nas CPU rises to 98/99% and the video freezes continuously every 4-5 seconds, it is impossible to watch normally. No problem if I open the same file with Synology Video Station instead of Plex (the video can be seen without problems and the cpu remains around 40%).

I did some research and I tried to edit the Preferences.xml file inside the Plex folder, adding VaapiDriver = “i965” at the end, but it doesn’t work.

What can I do to solve the problem? Please help me.

Thanks a lot to everyone.

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The reason it doesn’t work is, unfortunately, the DS418play is an ARMv8 CPU which has no such capability.

The i965 is only found in Intel CPUs.

Line 282 of

In testing, the ARMv8 CPUs were effective until about 20 Mbps of H.264 1080p.

Per your observations, Synology is licensed by Marvel to use the special features of the chip. Plex is not.

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The DS218play has limited transcode capability with Plex Media Server. At best it can transcode low bitrate 1080p video.

Reference: Plex NAS Compatibility List and NAS Compatibility Spreadsheet.

The i965 driver will have no effect, as your system does not use that driver. The DS218play has a Realtek ARM CPU. The i965 driver is used by certain systems with Intel CPUs.

If you want to run Plex Media Server on the DS281play, you need to avoid video transcoding. This means choosing the clients that can direct play your media and/or choosing media that can direct play on your clients.

For example, do not play H.265 video via Plex Web. Except for Safari, web browsers cannot direct play H.265 video. If watching on a Windows PC or Mac, use Plex for Mac/Windows. It direct plays most media, unlike Plex Web.

Also, do not enable PGS/VOBSUB/complex ASS subtitles when using a Plex SmartTV app (LG, Samsung, etc), as doing so results in video transcoding.

You will have better success with clients such as the AppleTV, Nvidia Shield, & Roku. They direct play many more video and audio formats than the SmartTV apps.

Another option is to run Plex Media Server on a more powerful system. This could be a Synology NAS with an Intel Celeron processor, a desktop PC running Windows or Linux, or similar. These systems will have greater transcoding capability than the ARM CPU in the DS218play. They can also take advantage of hardware accelerated transcoding, utilizing onboard or add-in GPUs.

Edit: Hardware Accelerated Streaming requires a Plex Pass. See Using Hardware Accelerated Streaming for additional details, including system requirements.

Regarding the hardware transcoding engine in the DS218play, Synology reserves it for use by their applications. They do not let Plex or other 3rd party applications access that capability. That is why their apps may be able to transcode H.265 video.

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Ok thanks to both of you.
You gave me a very good explanation and now everything is clearer to me.

Thank you so much.

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@ChuckPa @FordGuy61
At the moment I would like to continue using Plex on the NAS, I don’t have smart TVs and I use Chromecast 2nd gen. to watch video files H.264 (so without transcoding and without problems). To watch HEVC/H.265 videos without transcoding, do you think that a ‘Chromecast Ultra’ or the new ‘Chromecast with Google TV’ could be a good working alternative?

In 99% of cases, my video library consists of .mkv videos with h.264 or hevc/h.265 codecs.

Thanks a lot.

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@DaniWeb90

Check the specifications and make 100% certain of the capabilities.

Personally, I’m not a fan of requiring a 2nd device to control the player (computer/phone to “cast” to the TV).

I prefer the Set Top boxes. Nvidia Shield Pro 2019 / Apple TV 4K style.

They work by completely offloading the NAS:

  1. NAS sends all streams as DirectPlay
  2. The player app in the STB does all the decoding & rendering before pushing out the HDMI cable.
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@DaniWeb90

I prefer the STB approach as well.

I’ve a Nvidia Shield and Amazon FireTV 4K stick. Both work well. A family member has an AppleTV and is very happy with it.

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