Synology DS720+ can't transcode a single 1080p stream

Plex Media Server NAS & Devices
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Server Version#: Version 1.19.4.2935
Player Version#: Any

I am new to Plex so apologies if I have missed something. I’m struggling to get even one file transcoded successfully when accessing remotely on my Synology Ds720+. I believe everything is set up as it should be. I have Plex Pass and HW transcoding is on.

My internet Upload is 8-10 Megabit and download on the other side is 60. I’ve tested with a few files from 8-17gb, 8bit 1080p H264. I’ve tested with most settings - 1080p Mbps to 720p 2mbps or lower.

I’ve tried streaming on my iPhone and also in the web on my laptop through Chrome and a Mi Box. The files simply don’t load/play or are extremely choppy.

I don’t think it’s the upload speed as smaller files (3gb) direct stream fine, and downloading a file from the NAS is at max upload.

Any help massively appreciated! Thank you.

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There is a problem with the Intel video driver and the J4125 CPU that interferes with hardware accelerated transcoding. Until Intel fixes their driver, the workaround is to fallback to the older driver.

See Synology FAQ 26.

You can also turn off hardware accelerated transcoding. You should be able to transcode lower bit rate H.264 1080p video using the CPU, ~10 Mbps or less.

In addition to the FAQ, the Installation & Setup support document also has good information about running Plex on Synology NAS:

Additional References:

DS720+ has J4125 CPU per Synology.

Celeron J4125 Passmark = 3238.

Passmark ~2000 is needed to transcode 10 Mbps 1080p video on CPU. Ref: What Kind of CPU do I need for my Server?

1 Like
3

To add to @FordGuy61,

The bad video image is the first, and most convincing, evidence of the J4xxx CPU problem.

Using the IHD bypass will allow you to transcode again.

The CPU itself will still be subject to the normal passmark limitations of the J3xxx CPUs (mainly burning subtitles will be painful)

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Wow! I can’t thank you both enough. I switched it off and immediately the transcode was working. I’m ecstatic. A couple more questions just so I have a sense of everything.

  1. By using the bypass broken IHD driver method in the FAQ, I can then turn HW assisted transcoding back on in the settings and it will work as well as reducing CPU load?

  2. Is there somewhere I can subscribe to see driver updates? Is it likely to be fixed soon ( not in your hands I understand)

  3. When a working version is released will I need to edit the Preferences.xml file again to go to the updated version or it will be automatic from a Synology DSM update?

Thanks so much again.

6

I have a Synology DS 920+ (J4125 processor), as I am hard of hearing I do record with subtitling, Whilst I am trying to fix the issues in playback (it simple pause for 10seconds for approx every 2-3minutes, I tried the solution i.e. addin a bypass in Perference.xml as per Synology FAQ26. However when it’s recording the log simply states the following:-

TPU: hardware transcoding: enabled, but no hardware decode accelerator found
TPU: hardware transcoding: final decoder: , final encoder:

So it appears something is not right, so I removed the bypass, and attempt another recording and this also displays the same message, so are there no decoder at all for Synology DS920+?

Please advise?

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So no one from Plex Support is able to answer my question as to why there is no hardware decode accelerator on DS920+ with Intel J4125 processor? I am on Plex Version 1.19.5.3112.

TPU: hardware transcoding: enabled, but no hardware decode accelerator found
TPU: hardware transcoding: final decoder: , final encoder:

My previous server had Vaapi driver wording in it, but this server - nothing - so is it doing the job require of it?

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Present the log file ZIP please which captures this.

If you need to:

  1. Start playback
  2. let play 20 seconds
  3. stop
  4. wait 20 seconds
  5. Settings - server - troubleshooting - download logs
  6. attach the ZIP

I also need to know:

  1. Is this a Virtual DSM (VM) ?
  2. Is this a Docker PMS ?
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I have gone through these steps on my DS920+ and I cannot get the server to accept the changes via text editor. I have permission to R/W in the folder. I stop the PMS, edit the line of code, save, and run PMS. When I run PMS again, it’s like I’ve just installed it for the first time. It doesn’t remember my server name and I have to identify the folders. It essentially sets up a new server which I assume is overwriting the changes I made from FAQ26. I double check the line of code and my changes are no longer there. Video is still choppy and usually will not play outside of my home network. All I get is audio. Any thoughts?

1 Like
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Manually go to the Plex share in File Station
Navigate down until you see “Logs”
Right - click it and Compress to Logs.zip

When that is done, download to your computer and then upload here.
It seems you have a major configuration error.’

When manually editing the Preferences.xml , PMS MUST be in the Stopped state. If running, it will overwrite the changes. If made incorrectly, the changes will be dropped from the file.

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Logs.zip (1.3 MB)

Appreciate the help. Here is the log file. To confirm, I did stop PMS before making the edits.

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Do you have a local certificate in active use? The below is telling me PMS can’t communicate properly. Without that, it won’t be able to get codecs or authenticate.

 (3 live) GZIP 20000ms 5 bytes (pipelined: 16)
Jul 29, 2020 10:43:24.391 [0x7f639b79b700] DEBUG - Auth: authenticated user 1 as ClifCrawler9
Jul 29, 2020 10:43:24.391 [0x7f639886c700] DEBUG - Request: [192.168.1.141:54646 (Subnet)] GET /player/proxy/poll?deviceClass=pc&protocolVersion=3&protocolCapabilities=timeline%2Cplayback%2Cnavigation%2Cmirror%2Cplayqueues&timeout=1 (3 live) GZIP Signed-in Token (ClifCrawler9)
Jul 29, 2020 10:43:24.391 [0x7f639886c700] DEBUG - Content-Length is -1 (of total: -1).
Jul 29, 2020 10:43:25.114 [0x7f639b4ad700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 10:43:25.328 [0x7f639b79b700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 10:43:25.454 [0x7f639b4ad700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 10:43:25.641 [0x7f639b79b700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 10:43:26.211 [0x7f639b4ad700] DEBUG - EventSource: Resolving 192-168-1-141.521e930cf0f644d3bf8e82147d13b65c.plex.direct port 32400
Jul 29, 2020 10:43:26.221 [0x7f639b4ad700] DEBUG - EventSource: Resolved 192-168-1-141.521e930cf0f644d3bf8e82147d13b65c.plex.direct to 192.168.1.141
Jul 29, 2020 10:43:26.232 [0x7f639b4ad700] DEBUG - EventSource: Connected in 10 ms.
Jul 29, 2020 10:43:26.232 [0x7f639b4ad700] DEBUG - EventSource: Wrote data, reading reply.
Jul 29, 2020 10:43:26.233 [0x7f639b4ad700] DEBUG - EventSource: Read HTTP reply header.
Jul 29, 2020 10:43:26.234 [0x7f639b4ad700] DEBUG - EventSource: Successfully connected to 192-168-1-141.521e930cf0f644d3bf8e82147d13b65c.plex.direct.
Jul 29, 2020 10:43:31.552 [0x7f639b79b700] DEBUG - EventSource: Failure in ParseMessage (0 - Success).
Jul 29, 2020 10:43:31.552 [0x7f639b79b700] ERROR - EventSource: Retrying in 15 seconds.
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I do have another PMS locally running on another PC because the Synology PMS was so terrible. Do I need to stop the second PMS as well?

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No. I run 5 here in my office, all concurrently.

Let me continue reviewing the logs.

I did notice, you do don’t have locale or the codepage setup. All your characters came through as UTF-16 when they should be UTF-8.

There is something going on with your networking or ISP. I’m looking through everything right now but it does seem to focus on PMS not being able to authenticate due to SSL not working. Without that, PMS will not work because everythng is HTTPS

Your username can authenticate but PMS itself cannot.

Jul 29, 2020 09:42:39.694 [0x7f7b2b783700] DEBUG - Auth: authenticated user 1 as ClifCrawler9
Jul 29, 2020 09:42:39.694 [0x7f7b2ab7c700] DEBUG - Request: [192.168.1.141:51883 (Subnet)] GET /media/providers (13 live) GZIP Signed-in Token (ClifCrawler9)
Jul 29, 2020 09:42:39.696 [0x7f7b2b783700] DEBUG - Completed: [192.168.1.141:51883] 200 GET /media/providers (13 live) GZIP 2ms 4168 bytes (pipelined: 2)
Jul 29, 2020 09:42:39.718 [0x7f7b2ba71700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 09:42:40.016 [0x7f7b2ba71700] DEBUG - CERT: incomplete TLS handshake: sslv3 alert certificate unknown
Jul 29, 2020 09:42:41.741 [0x7f7b2911e700] ERROR - Error issuing curl_easy_perform(handle): 7

Did you have the Syno generate a certificate for you?

15

Logs.zip (683.4 KB)

I uninstalled the Plex package and reinstalled and went through the process again. It seems to be working better now and the code edit saved. I uploaded my new logs for you.

Will this code edit need to be done each time the Plex version is updated?

16

Whatever you did, resolved it .

  1. I can read your logs now as I should in a normal text editor.
  2. I see everything working.
  3. You will not need do this again
  4. If you want to add the VaapiDriver="i965" bypass, with Plex stopped, it will persist now.

I you have IPv6 enabled (Syno default). If you don’t need it (which it appears you don’t), I recommend turning it off in Control Panel - Networks. It keeps things even cleaner.

1 Like
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Perfect! IPv6 turned off now as well. Really appreciate your help! I was very discouraged after getting the NAS specifically to run PMS and falling into issues. Looks to be running more as expected now.

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As long as you don’t attempt to burn subtitles – you’ll be very happy with Synology.

Their CPUs don’t have a lot of strength to do that. (Subtitles have to be done by the CPU. The integrated video processor doesn’t provide an interface to Linux for burning them – yet)

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