Batch ffmpeg conversion: windows to linux
Adapted from How do you convert an entire directory with ffmpeg?
mkdir out
for i in *.mp4; do ffmpeg -i "$i" -filter_complex "[0:v]setpts=PTS/1.5[v];[0:a]atempo=1.5[a]" -map "[v]" -map "[a]" "out/${i%.*}.mp4"; done