When playing OPUS files from Jellyfin (encoded with ffmpeg) no duration is shown. I’ve tried clearing all caches in Symfonium and cleared the cache from the system settings. During the logs, one song randomly had a duration. Have never seen it before.
Link to download the source opus file: https://icelk.dev/symfonium-sample.opus
Upload description: icelk
Play any opus song.
Jellyfin
Open that file in Chrome and it won’t show the duration either.
What parameters do you use to encode the files ?
You could try the +faststart option it helped me in another problem with opus.
True, but after downloading it it works 
I also noticed that the OPUS files I encoded a few months ago work just fine. So maybe a regression in opusenc / ffmpeg??
This is the command I run: (previously I ran with flac.opus to use the opus container but that didn’t work either)
ffmpeg -i "<>.flac" -c:a libopus -b:a 320k -ar 48000 -y "<>.flac.ogg"
IIRC +faststart only works for mp4 and related containers? I use the opus container. And I also tried the OGG container and it didnt work either.
Maybe but you are streaming 
Not an expert of that format, but when Chrome will work it will work too.
I know that the docs say that. I only report what helped me maybe it was something different and it was coincidence that it happened after i used faststart. (Or it was m4a and not opus)
So maybe give it a try even if it should do nothing.
Changing to the MKA/MKV container worked
So maybe give it a try even if it should do nothing.
Yeah I did and ffmpeg was not happy… Thanks anyway 
Maybe but you are streaming
True true 
Yes, putting it into a matroska file fixed the issues. Wonder why chrome has problems reading plain opus files being encoded recently…