HW Transcoding broken

Plex Media Server
,
1

Server Version#: Public latest 1.40.3.8555 and now Beta 1.40.4.8626
Player Version#: LG TV latest: 5.85.0 and Roku latest stable and Android latest: 10.18.0.968

My server will not transcode anything anymore. I have Plex 64 bit running on Windows 11 on Intel I5-12600k with 16gb ram and plenty of drive space. I used to be able transcode audio all day long and video transcode it down to what ever all day locally and now nothing transcodes. I even get errors on my Roku saying Network is weak or something like that. The biggest problem is my LG G2 TV won’t play anything that requires any transcoding. So if I need to play a 4k movie with DTS, it used to transcode it down to 4k video with aac or similar audio which played great no buffering. No it plays for about 10 seconds at most and then Orange buffering wheel and then errors out after about 30 seconds of sitting there. Every movie and file I have to transcode does nothing. Transcoding is broken on my server now.

I’m not sure if this happened when I updated to 64bit or not. I’m not sure of the date when that happened either. But it was a few months back and I wasn’t watching many movies, just TV shows that didn’t need transcoding.

Plex Media Server Logs_2024-07-15_23-40-54.zip (6.2 MB)

2

Whatever was on pastebin has been removed. You can attach log files to Plex forum posts. Just drag the file into the message window.

Do you have subtitles enabled? If so, turn them off and see what happens.

Plex may be burning the subtitles into the video stream. That uses the CPU, and if the CPU cannot perform the task in real time, you’ll experience buffering, timeouts, etc.

Also, when running Windows, Plex does not support hardware accelerated tone mapping when using Intel graphics. So, when transcoding HDR media, the tone mapping will also use the CPU.

You can monitor playback via the Plex Dashboard. It will show if the video or audio is transcoding and if subtitles are being burned into the video stream.

Regarding the clients you mentioned:

Roku: PGS subtitles are burned into the video stream.

LG: If the media is direct streaming, such as when audio is transcoding, enabling any type of subtitle results in a video transcode and subtitle burning.

3

I seem to be having a similar issue since the latest beta update. When transcoding is attempted the log shows a 404.

Windows Plex Media Server: Beta Version 1.40.4.8626

Jul 08, 2024 09:42:27.590 [6108] DEBUG - Request: [47.39.2x.x:39915 (WAN)] GET /video/:/transcode/universal/session/97eceb75-6905-4449-ac15-2a58e180efce-20/base/00001.ts?protocol=hls&mediaIndex=0&waitForSegments=1&videoQuality=60&session=97eceb75-6905-4449-ac15-2a58e180efce-20&maxVideoBitrate=2000&mediaBufferSize=50000&offset=0&partIndex=0&videoResolution=1024x768&directPlay=0&path=%2Flibrary%2Fmetadata%2F970760&directStream=1&skipSubtitles=1 (38 live) #4b96bb TLS Signed-in Token (UserName)
Jul 08, 2024 09:42:27.591 [11808] DEBUG - Completed: [47.39.2x.x:39915] 404 GET /video/:/transcode/universal/session/97eceb75-6905-4449-ac15-2a58e180efce-20/base/00001.ts?protocol=hls&mediaIndex=0&waitForSegments=1&videoQuality=60&session=97eceb75-6905-4449-ac15-2a58e180efce-20&maxVideoBitrate=2000&mediaBufferSize=50000&offset=0&partIndex=0&videoResolution=1024x768&directPlay=0&path=%2Flibrary%2Fmetadata

4

Is this possibly related to this issue?

There is a test Plex build there they claim could address this very similar issue.

5

That test version didn’t work for me, so I just installed the Public version, dumping the beta, and now it transcodes again. Something going on with the Transcoding capability in the beta version.

6

I am seeing similar with a Shield client which is now causing software transcoding rather than hardware on Plex windows server.

1 Like
7

Disabling subtitles worked for me, thank you! Is there a way to enable subtitles without causing this issue.

10

My issue was on Public first then I tried Beta and both fail the same way.

11

I was not using Subtitles and if/when I do, I make sure they were SRT so they wouldn’t cause Plex to crash/buffer forever. Subtitles have not been on when this happens. Like I said this seems to be a relatively recent problem. I wasn’t watching many movies lately, especially with DTS (that normally would Transcode just fine with 4k). But this started for me a couple weeks ago and all my users see it too. Anything that causes transcoding just goes into a infinite buffer that ultimately stalls the video. I can’t even watch a 720p movie locally on LG TV because it has DTS and transcodes for like 10 seconds and then all of a sudden the Bandwidth graph jumps to way above 100mbps or 180mbps sometimes and then buffers indefinitely.

This all started on the Public release and then 2 nights ago I tried the Beta and it didn’t fix it. Is there a way I can attempt to fall back to a couple versions ago of Public?

12

Also another note to help narrow this down, I even tried another version of a few of the movies that wouldn’t work. I tried them still in 4k but with an audio that my TV could passthrough (Dolby Digital AC3). These new files play just fine but every movie with DTS now won’t play past 10 seconds. Some of my highest bitrate movies in 4k play just fine because they have Audio that will passthrough and won’t need transcoding. This wasn’t an issue up until recently.

13

I get the 404 also. But I also see this:

Jul 10, 2024 15:34:14.949 [19208] WARN - [Req#64edf/Transcode] Got a request to stop a transcode session without a valid session GUID.

14

added my logs and just had the new normal failure about 30min ago.

15

2 remote Plex clients (Shield Pro) are totally ignoring the 1080p max transcoding restriction (server and/or client side) and playing at 4K HDR. The setting to treat WAN as LAN is confirmed as disabled.

16

I attached server logs. Please tell me what is going on with my server. It really won’t Hardware Transcode any more. It buffers every 10 seconds or so on files I force to smaller stream sizes and it won’t play anything with DTS audio. Plex used to change this an audio that my LG tv would play using Transcoding but now fails.

17

Thanks for pinging me. Apologies for delayed reply. I lost track of the thread.

List of IP addresses and networks that are allowed without auth

The only thing I see wrong in the log files are entries for devices allowed without authorization (Settings → Network).

Jul 15, 2024 22:27:54.195 [21996] ERROR - Error parsing allowedNetworks entry ' 192.168.0.109': An invalid argument was supplied [system:10022]
Jul 15, 2024 22:27:54.195 [21996] ERROR - Error parsing allowedNetworks entry ' 192.168.0.108': An invalid argument was supplied [system:10022]
Jul 15, 2024 22:27:54.195 [21996] ERROR - Error parsing allowedNetworks entry ' 192.168.0.111': An invalid argument was supplied [system:10022]
Jul 15, 2024 22:27:54.195 [21996] ERROR - Error parsing allowedNetworks entry ' 192.168.1.222': An invalid argument was supplied [system:10022]

You’ll need to correct the syntax or remove the entries. If you leave the addresses, make sure there is no space after the comma: 192.168.0.108,192.168.0.109,192.168.0.111,192.168.1.222.

LAN Networks

Given the above addresses, it appears you have clients on multiple subnets. If so, you should add them to Settings → Network → LAN Networks: 192.168.0.0/24,192.168.1.0/24 ← again, no space after the comma.

Transcoding

The only playback attempt captured in the log files is for European Vacation. The video did not need transcoding, so hardware transcoding was never invoked.

The audio was transcoded to MP3 and then the stream was terminated by the LG TV.

Jul 15, 2024 22:59:59.361 [1888] DEBUG - [Req#13ef] Streaming Resource: Terminated session 000002284E5CC400:gk97izpaib7fs11ke4jxy6zd with reason Client stopped playback.

Suggestions

Fix the syntax problems with Allowed Networks.

In Settings → Transcoder, pick the Nvidia 1070 as the Hardware Transcoding Device. It is the only GPU that can perform hardware accelerated tone mapping. Support for tone mapping with Intel graphics will be available in PMS 1.41.0.

In the LG Plex app settings, make sure DTS audio is NOT selected, since the G2 does not support the format (I didn’t see anything in the logs, just a double check).

If the problem with hardware transcoding persists, run a test:

  1. Play a video that direct plays. Something simple like H.264, 1080p, AC3 or EAC3 audio, no subtitles.
  2. Force a transcode by changing the bitrate/resolution in the Plex LG app.
  3. Monitor playback via Plex Dashboard → Now Playing + Expanded View to see if Plex is using hardware accelerated transcoding.
  4. If not, stop playback, give the server two minutes to settle down, then pull & post a new set of log files.
1 Like
18

I’ll fix the IP addresses, I didn’t know about the spaces and if still needed I’ll do your suggested test tonight after work.

Thank you for the quick response last night!

19

Well that might have been the fix
 Not sure 100% yet though. I still have this one movie ( European Vacation) with DTS audio that software transcodes and freezes after only about 30 seconds every time and at different spots.

However, I did the IP address fixes, made sure DTS was still unchecked in LG app, changed the HW Transcoder over to my Nvidia 1070 gpu and now other files with 4k and DTS seem to play just fine and are still full 4k HDR and audio gets software transcoded on the fly. I then tried a bunch of good 4k HDR files with good audio (AC3) and then told it transcode down to like 8mbps 1080p or 720p and they played great! Yes from the Plex Dash expanded view I could see all videos were HW transcoding correctly. I played them all at least 10 minutes and each had no buffering. Seems my only problem is the European Vacation movie. I’ll try another encode of it tomorrow before I call this resolved.

Edit: it does seem like a couple movies WITH DTS and 1080 or 4k freeze and buffer infinitely after playing for about 30 seconds. When viewing in dash it says no HW transcoding for just audio so just software. So if I force the video to HW transcode by picking lower Mbps transcode in the LG player, it plays great! I don’t know why some files won’t software transcode anymore and some do.

20

@crimsonfury

Checking in. Is hardware accelerated transcoding still working?

If you’re still having trouble with European Vacation, you might try remuxing it with MKVToolNix, or, if you have access to the disc, re-ripping it with MakeMKV.

21

HW transcoding is working on everything now yes. Works with my 1070 gpu and with the I5 12600k igpu. Yes Euro Vacation is still having issues because it’s SW transcoding only the audio. But if I force it to HW transcode by lower the quality down 1 step it HW trancoded just fine. This happens on all movies that require audio to be SW transcoded. It will freeze after less than 30 seconds of playing and then crash after the infinite buffer. Looking at the Dash my bandwidth spikes high on those “bad” audio movies. Spikes reach like 160mbps then dip real quick then spike again, does that a few times then spikes to 140-160mbps and stays there for 10 seconds until frozen.

So I guess now I ask, is SW transcoding broken in Plex windows server or is it broken in the LG Plex app?

22

Media does not stream at a steady rate. Bandwidth spikes are normal. When the client buffer needs refilling, PMS tries to refill it as fast as possible. The spikes are more noticeable when streaming locally (instead of remotely) because of the available bandwidth - server on gigabit Ethernet, clients on wi-fi can support hundreds of megabit/sec.

I do not think the problem is HW vs SW transcoding, but that transcoding the video cleans up some other issue. You could test by disabling HW transcoding. PMS would then transcode video using the CPU. You should see the same results as when using HW transcoding.

Unsure if the problem is with the Plex LG app. I’ve not noticed similar reports (but I don’t monitor that section of the forum regularly). You could try using another client such as Plex Web (mentioned below).

Some things to try:

Delete codecs in Plex Data Folder.

There may be a problem with the codecs. Deleting them will force PMS to download new copies from plex.tv.

  1. Stop Plex Media Server
  2. Go to %LOCALAPPDATA%\Plex Media Server\Codecs
  3. Delete the contents in the Codecs directory.
  4. Start Plex Media Server.
  5. Give the server a couple of minutes to start, then play something.

Try a different client, such as Plex Web.

This takes the Plex LG app out of the loop.
Plex Web supports H264 video, but not DTS audio, so it will force the audio to transcode.
See if you still have playback problems.

Remux the file with MKVToolNix or similar tools.

The container may be damaged or the tracks may be poorly interleaved. Remuxing will clean up both. The video/audio/subtitle tracks are not transcoded, just copied into a new file.

You can also remux using ffmpeg: ffmpeg -i input.mkv -map 0 -c copy output.mkv