for file in *; do
ffmpeg -i "$file" -vcodec libvpx -qmin 10 -qmax 20 -rc_lookahead 25 -keyint_min 0 -g 360 -skip_threshold 0 -slices 2 -threads 8 -vf ass="$file.ass" -acodec libvorbis -y "${file%.???}.webm"
mkclean --optimize --remux "${file%.???}.webm" "${file%.???}c.webm"
rm "${file%.???}.webm"
mv "${file%.???}c.webm" "${file%.???}.webm"
done