#!/bin/bash
for file in *.mp3; do echo "file '$file'" >> mylist.txt ; done
ffmpeg -f concat -i mylist.txt -c copy output.mp3
ffmpeg -r 1 -loop 1 -i "cover.jpg" -i output.mp3 -c:v libvpx -c:a libvorbis -shortest z.mkv
rm "output.mp3"
rm "mylist.txt"