images

resize

magick %04d.jpeg -set option:wd "%[fx:(16/9)>(w/h)?(16/9*h):w]" -set option:ht "%[fx:(16/9)>(w/h)?h:(w/(16/9))]" -gravity center -background black -extent "%[wd]x%[ht]" %04d-16_9.jpg

pillarbox

mogrify -resize 1920x1920 -background black -extent 1920x1920 +repage -gravity center *.jpg

fit

mogrify -resize 1080x1080 -background black -extent 1080x1080 +repage -gravity center *.jpg