Playback failed with error "unrecognized file format"

[M B]

jellyfin 10.10.7

so one only one of my computers that has nvidia 3060 12gb I am having this error 

Playback failed with error "unrecognized file format". Retry with transcode? (Note this may hang the player.)

the error does not appear in the web player, only in the full on desktop app player.
the H265 content plays fine, but the H264 content seem to show this error . 

i tried different settings under the client settings/video, but did not seem to find a successful combination.

[M B]

it seems to affect only H264 1080 videos.. maybe there is something else to it

[theguymadmax]

Logs, both server and ffmpeg.

[M B]

ok this is weird i cant reproduce it now.
all i did is corrected the password for open subtitles plugin.

[M B]

and now it is back

I have DMed you the logs thank you very much!

[M B]

here is what is weird in the client log

2025-06-14 21:29:36.994 [critical] unknown @ 0 - ffmpeg: tcp: Failed to resolve hostname media.lan: The name does not resolve for the supplied parameters

so for some reason , even if we are addressing a local server in my home network, ffmpeg cant resolve it.

why? does ffmpeg has its own dns configuration??