AudioToolbox init error

[Jorge Oliva]

Hi there,

I'm quite new to Jellyfin, and after restarting my Mac (and therefore the Jellyfin server), I've started encountering a playback error. Some of my viewers (namely, my girlfriend) reported that certain episodes no longer play. Jellyfin tries to start the stream but then throws an error.

   

The error shown is the typical playback error message (in Spanish, since I'm based in Spain).

After checking the logs, I found this clear error message:

Code:

MediaBrowser.Common.FfmpegException: FFmpeg exited with code 171

Full relevant log except:

Code:

vod -hls_list_size 0 -y \"/Users/jorge/Library/Application Support/jellyfin/cache/transcodes/a6b9f507171f18fd2def3211ca9a6eae.m3u8\"
[2025-06-26 16:52:54.308 +02:00] [ERR] [97] MediaBrowser.MediaEncoding.Transcoding.TranscodeManager: FFmpeg exited with code 171
[2025-06-26 16:52:54.386 +02:00] [ERR] [40] Jellyfin.Api.Middleware.ExceptionMiddleware: Error processing request. URL "GET" "/videos/2d478859-1e57-fd1e-ad46-dba7953e8dd5/hls1/main/-1.mp4".
MediaBrowser.Common.FfmpegException: FFmpeg exited with code 171

I also checked the "FFmpeg.Transcode...log" and found this very interesting line:

Code:

[aac_at @ 0x7fa5c001cc80] AudioToolbox init error: 1718449215

Here's the full log on Pastebin: https://pastebin.com/wYtN3CVX

I'm not an expert, and as I mentioned, very new to Jellyfin. From what I’ve researched, AudioToolbox is a macOS framework related to audio encoding.

I also ran /ffprobe on the media file to inspect the codecs, and here is the output: https://pastebin.com/SaBtXQui

The audio codec is eac3, and I read that this codec sometimes causes problems on macOS.

So now I have a few questions:

1. Is this a known issue? I haven’t found much documentation about it.
   
2. Could this be an issue with macOS itself? Do I need to install or reconfigure something?
   
3. Could this be a Jellyfin configuration issue?
   
4. My girlfriend says she could watch the same episode before the restart. Is it possible that something changed during the reboot?
   
5. And of course — what’s the solution?
   
   

Thanks in advance for any help!

[gnattu]

The error code is kAudioConverterErr_FormatNotSupported which is super abnormal on a standard macOS install. We are already requiring macOS 12+ in our main app so all macOS install should support the requested encoding format (we are encoding to aac).

I do think your system might be running in an abnormal state and I suggest you to first shut down your server entirely (not reboot, but shut down, and uncheck the "reopen windows when log back in"), and then start jellyfin again to see if it recovers.