joinvid.sh

#!/bin/bash
echo "joining files $1 and $2 ..."
name=$( echo "$1" | sed 's/\ \(Part [0-9]\)//' | sed 's/\ \[[0-9]of[0-9]\]//' )
avidemux --nogui --load "$1" --append "$2" --save "$name"
echo "saved as $name"