Cutting a video segment with fading in and out using ffmpeg:

ffmpeg -i tp.mp4 -ss 1:18 -to 3:20.5 -vf "fade=type=in:start_time=0:duration=3,fade=type=out:start_time=193:duration=3" output_tp.mp4

now incl. audio, replace 127 with duration -3:

ffmpeg -i out.mp4 -vf "fade=in:st=0:d=3, fade=out:st=127:d=3" -af "afade=in:st=0:d=3, afade=out:st=127:d=3" output_faded.mp4

Creating a Spotify canvas video (720×1280) using ffmpeg:

ffmpeg -i "$1" -vf "scale=720:-1,pad=720:1280:(ow-iw)/2:(oh-ih)/2:black" -c:a copy "$2"