Will updating FFMPEG break my current setup?

[TheDreadPirate]

I just noticed this bit.  Emphasis mine.

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My reasoning for updating is to eliminate the transcoding bit all together. Newer decoder package, updated file info, thus easier playback. I haven't excused that this may be a Roku limitation by any means, but I just want to verify and the like, Feel me?

Upgrading ffmpeg will not eliminate transcoding.  Since ffmpeg only runs when transcoding is occurring.  I also noticed in your log that you are software transcoding instead of hardware accelerated.

You said your server is on Windows.  Which version of Windows, what are the hardware specs, and what do your transcode settings in Jellyfin the dashboard look like? Settings > Dashboard > Playback.

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One more thing. In the log directory, the "log_(date).log" file will contain the "TranscodeReason". That will help us figure out why these 2% of files are transcoding while the other 98% are direct playing.