Some Bash scripts for turning a portrait video into landscape with blurred background

toLandscape () { echo "Processing $1"; convert -respect-parentheses \
\( $1 +write mpr:original \) \
\( mpr:original -resize 690x1080! -blur 0x25 +write mpr:blurred \) \
\( -size 1920x1080 xc:SkyBlue \
   mpr:blurred -geometry 1920x1080 -gravity northwest -composite \
   mpr:blurred -geometry 1920x1080 -gravity southeast -composite \
   mpr:original -geometry 1920x1080 -gravity center -composite \
   -size 1920x1080 -quality 100 +write $1 \) NULL:; }; export -f toLandscape

shave () { convert $1 -shave 8x0 $1; }; export -f shave

toFrames () { mkdir -p frames; ffmpeg -i $1 -vsync 0 -f image2 frames/frame-%05d.png; }; export -f toFrames

forEach () { seq -f "frame-%05g.png" 1 $1 | xargs -P 6 -I {} bash -c 'toLandscape "$@"' _ {}; }; export -f forEach

toVideo () { ffmpeg -thread_queue_size 65536 -r 30 -f image2 -s 1920x1080 -i frames/frame-%05d.png -i $1 -map 0:v:0 -map 1:a:0 -vcodec libx264 -crf 17 -pix_fmt yuv420p -shortest LANDSCAPE_$1; }