>>108962629
I use Avidemux to cut/crop videos with a lossless codec like huffyyuv and then encode the file with ffmpeg..
ffmpeg -y -i .mkv -pass 1 -c:v libvpx-vp9 -b:v 4096*8.192/12.440*.996k -threads 4 -row-mt 1 -tile-columns 2 -tile-rows 2 -an -f webm NUL
ffmpeg -i .mkv -pass 2 -c:v libvpx-vp9 -b:v 4096*8.192/12.440*.996k -threads 4 -row-mt 1 -tile-columns 2 -tile-rows 2 -an .webm
change -threads to however many cores your pc has