How can i know if ffmpeg is doing SW or HW transcoding

hello guys

i’ve been using jellyfin on ubuntu for a long time with success, but a few weeks back my friends have been having buffering issues. so i had to set max stream bitrate to 720p 4mbps.
even tho they have 150mbit connections at home, and i have 40mbit upload. my dell t40 server should be powerful enough to do several 1080p transcoding instances at once

i suspect that for whateaver reason ffmpeg is sw and not hw transcoding (when i enable transcoding on the jellyfin playback options buffering starts)

this is my jellyfin log:
here is my ffmpeg log:

could someone please guide me?

thx in advance