Server Version#: 1.21.1.3876
Player Version#:web version or on TV
When I enable subtitles for a recorded TV show the video will buffer every minute or so. If I turn off the subtitles it plays fine. What gives?
What you’re describing is when PMS, after checking with the player as you click “Play”, determines it can’t send the subtitles as they are.
When PMS can’t send them as the third data stream with the audio & video, it burns the subtitles into the video for that playback.
Most players can handle text-based subtitles easily. SRT type subtitles are the most widely supported.
Image based subtitles (PGS, VOBSUB, and DVDRIP) are images. Players can’t overlay these during the playback. This is why PMS invokes transcoding to burn them in.
What you’re describing is the situation where subtitles are being burned in but your processor doesn’t have enough speed (CPU power) to keep up with real-time playback demand.
Your log files, captured right after starting a playback session (which you can stop after 20 seconds) , will show us exactly what’s happening.
Ok, I did top on the linux before and after enabling the subtitles.
Then as soon as i choose subtitles and the video not playing.
Then as soon as I hit play.
So what is the solution for this? I am running Plex on ubuntu 20 with 2 CPUs and 8 GB of RAM. My DVR is an HD Homerun Extend. I thought since this device has a transcoder built in it would perform some of the processing power over there.
May I have the log files please?
What you show above, if you have TWO CPUs on one motherboard, tells me those CPUs are NOT fast enough.
This is why I need to see the log files. Either those Xeons are extremely old or you’re trying to burn subtitles into some very high bitrate video (which might still be more demand than they can provide).
(( Burning of subtitles is a Single-Threaded task. Xeon CPUs are very good at many / massive parallel tasks but not at tasks such as this. These type tasks need the more generalized Destkop CPUs ( Core i5 / i7 class )
Here are the logs. I tried playing back a TV show at 10:37 without subtitles and then at 10:38 with subtitles. Then at 10:39:55 the show hangs. Yes you are right these are older Xenons and I bet since i7/i5s work better has to do with Quick Sync Video. I am running Plex as a VM on ESXi 6.5.
There are 2 Xeon® CPU E5520 @ 2.27GHz on the server. I have apportioned to the Plex 2vCPUs. I have been thinking of upgrading my ESXi box to a more current processor but I have been a little lazy. Plex Media Server Logs_2021-01-29_10-40-33.zip (5.3 MB) I have been reading that some people use handbrake or MKVToolNix and extract thr subtitles out to a .srt file. It seems they also convert the .ts file to a variety of formats. What is best practice here?
If you want the option to have subtitles or not, you want to convert them yourself (if they are images this uses OCR to try and turn them into txt you then need to review) or replace them with existing text based ones (many online sources for subtitles for things, might need a slight sync adjustment to match your video but the text shouldn’t need proofreading).
If you use handbrake during encoding you can “burn” them but this is then including the subtitles in the video data, can never be turned off or removed.
Having said that you have given plex 2 cpu cores it sounds like. If you have the capacity you can increase the resources to the VM and see if it improves.
So it seems if I optimize the file from inside of Plex to TV Quality it will run smoothly and the CPU drops down to nothing. I guess now I understand why people script it out to mp4. Then the Plex server doesn’t have to transcode it again. Is that the best approach or does leaving it as a .ts file?
Regard 2 VCPUs – Increase. you need at least 4. Current NAS processors have a higher passmark score. A dual-core NAS machine with this rating always has issues due to lack of performance. Quad core at this level do fairly well.
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