Official Jellyfin documentation

Codec support

Hardware acceleration support

NAS Compatibility sheet from Plex

Minimum CPU guideline per resolution

Test files: https://jell.yfish.us/

TLDR: maybe don’t bother transcoding 4k. Always prefer to store your media in a compatible format for direct play. Plex has come a long way since but the ffmpeg version in use here isn't the proprietary Plex transcoder (ffmpeg fork).

Verifying Transcodes

To verify that you are using the proper libraries, run this command against your transcoding log. This can be found at Admin Dashboard > Logs, and by using SSH. For DSM 6 and below look in /var/packages/jellyfin/target/var/log/ and for DSM 7 look in /var/packages/jellyfin/var/log/.

grep -A2 'Stream mapping:' /var/packages/jellyfin/target/var/log/ffmpeg-transcode-85a68972-7129-474c-9c5d-2d9949021b44.txt

This returned the following results.

Stream mapping:
Stream #0:0 -> #0:0 (hevc (native) -> h264 (h264_omx))
Stream #0:1 -> #0:1 (aac (native) -> mp3 (libmp3lame))

Stream #0:0 used software (VAAPI Decode can also say native) to decode HEVC and used HWA to encode.

Stream mapping:
Stream #0:0 -> #0:0 (h264 (h264_mmal) -> h264 (h264_omx))
Stream #0:1 -> #0:1 (flac (native) -> mp3 (libmp3lame))

Stream #0:0 used HWA for both. h264_mmal to decode and h264_omx to encode.

Troubleshooting

Endless spinning login screen or migrated from docker

Please clear your cookies and browser cache. And try again.

Not transcoding and log contains permission denied.

This client isn't compatible with the media and the server isn't sending a compatible media format.

Please check that you have given sc-jellyfin the correct permissions. If you are having this problem on DSM 7 check that sc-ffmpeg also has read permissions to the same folders as sc-jellyfin.

armadaxp (DS414) Illegal instruction

This CPU architecture is not supported at the moment. See #4790 and 4793

unofficial: Jellyfin working on evansport arch CPUs NASes like DS214Play (x86)