Soundpost Conversion (By Pankophile)

#!/bin/bash

echo -e "Usage: this-script.sh <soundpost>"

soundpost=$1
soundpostfilename=${soundpost##*'/'}
afterdot=${soundpostfilename##*'.'}
name=${soundpostfilename%%'['*}
beforebracket=${soundpostfilename%%']'*}
soundsource=${beforebracket##*'['}
link=$(echo "$soundsource" | tail -c +7 | sed 's|%2F|/|g')
sourceafterdot=${link##*'.'}
soundfile="/tmp/soundsource.$sourceafterdot"

echo "Sound source located as $link"

wget "$link" -O "$soundfile"

if [ "$afterdot" == "gif" ]; then
    ffmpeg -stream_loop -1 -i "$soundpost" -i "$soundfile" -shortest -c:v libvpx-vp9 -c:a libopus "$name.webm"
elif [ "$afterdot" == "png" ] || [ "$afterdot" == "jpeg" ] || [ "$afterdot" == "jpg" ]; then
    ffmpeg -i "$soundpost" -i "$soundfile" -c:a libopus "$name.webm"
else
    ffmpeg -i "$soundpost" -i "$soundfile" -c:v copy -c:a libopus "$name.$afterdot"
fi