I personally had really huge problems in the beginning with this feature, it depends on the file format, if it needs to be transcoded, if the subs are external or in the video container and what your users are watching it on.
I can give you some advice on what to look for, but it will come down to just tinkering with the settings until you find something that works for you the best.
Hardware acceleration is quite important, especially when there are like 6 people watching at once and 4 of them just refuse to watch it using the jellyfin desktop client that actually supports direct play feature (video does not need to be transcoded).
Switching languages of subtitles sometimes mess things up, especially when the subtitles need to be extracted from the video container and then sent separately. Sometimes it just lags the video for up to two seconds. It usually just messes with one person that then is a few seconds behind so not a big deal. Although I recommend setting languages in the very beginning so it does not break sync mid-way.
I also limited the thread count of the single ffmpeg stream to just one. Then i also limited the stream buffer to like 5 minutes so it just won’t try to prepare a 4k movie for one person for the next several minutes. From my experience anyways, when we were watching some movie that is quite big, the jelly went bananas and a single user just maxed out the CPU and GPU. Ever since I set those limits, while also having the hardware acceleration enabled, the sync-play feature caused me little to no trouble. — One of my friends has a slow internet that sometimes likes to drop things on the way and when his net drops out totally, it usually causes some issues and he then has to restart the browser tab. Although rare, it still happens from time to time.
I have an Intel i5 8400 and a UHD Graphics 630. The performance is good enough for my uses and movies play without issues even when 6 people are watching while my dad sits on tv while also watching something else.
Oh yes, now there are also a few other things to worry about. Make sure to check the maximum per-user bitrate the jelly will enable the users to watch. It’s 40Mbps by default, I think. And you do not really need anything above it anyways, especially if streaming over the public internet.
The second thing is having a Nvidia GPU. From what I heard, the consumer graphics card can have up to 3 consecutive video streams running at once. But since I do not have anything Nvidia, I can’t really care, tho I would strongly recommend you checking the GPU limitations including both the encoder/decoder limits and the codec support. This will help you set the buffer limits and codec support.
So full wrap, you’ll just have to monitor your server’s vitals and see if there is a bottleneck. Check your users client compatibility, see if the GPU or CPU is maxed out or if your ISP just isn’t giving you a big enough pipe.
It just comes down to tinkering.
Is there some trick to get it to work properly? Everytime I tried to use it, it works fine for like 10 minutes and then everyone desyncs to hell.
It’s still better than Plex’s which didn’t work at all though.
Ah, strange.
I’ve never had any issues, but I also haven’t used it in a while.
Might be related to transcoding/sub-burning? https://github.com/jellyfin/jellyfin-web/issues/6210
I personally had really huge problems in the beginning with this feature, it depends on the file format, if it needs to be transcoded, if the subs are external or in the video container and what your users are watching it on.
I can give you some advice on what to look for, but it will come down to just tinkering with the settings until you find something that works for you the best.
Hardware acceleration is quite important, especially when there are like 6 people watching at once and 4 of them just refuse to watch it using the jellyfin desktop client that actually supports direct play feature (video does not need to be transcoded).
Switching languages of subtitles sometimes mess things up, especially when the subtitles need to be extracted from the video container and then sent separately. Sometimes it just lags the video for up to two seconds. It usually just messes with one person that then is a few seconds behind so not a big deal. Although I recommend setting languages in the very beginning so it does not break sync mid-way.
I also limited the thread count of the single ffmpeg stream to just one. Then i also limited the stream buffer to like 5 minutes so it just won’t try to prepare a 4k movie for one person for the next several minutes. From my experience anyways, when we were watching some movie that is quite big, the jelly went bananas and a single user just maxed out the CPU and GPU. Ever since I set those limits, while also having the hardware acceleration enabled, the sync-play feature caused me little to no trouble. — One of my friends has a slow internet that sometimes likes to drop things on the way and when his net drops out totally, it usually causes some issues and he then has to restart the browser tab. Although rare, it still happens from time to time.
I have an Intel i5 8400 and a UHD Graphics 630. The performance is good enough for my uses and movies play without issues even when 6 people are watching while my dad sits on tv while also watching something else.
Oh yes, now there are also a few other things to worry about. Make sure to check the maximum per-user bitrate the jelly will enable the users to watch. It’s 40Mbps by default, I think. And you do not really need anything above it anyways, especially if streaming over the public internet.
The second thing is having a Nvidia GPU. From what I heard, the consumer graphics card can have up to 3 consecutive video streams running at once. But since I do not have anything Nvidia, I can’t really care, tho I would strongly recommend you checking the GPU limitations including both the encoder/decoder limits and the codec support. This will help you set the buffer limits and codec support.
So full wrap, you’ll just have to monitor your server’s vitals and see if there is a bottleneck. Check your users client compatibility, see if the GPU or CPU is maxed out or if your ISP just isn’t giving you a big enough pipe. It just comes down to tinkering.