#!/bin/bash
hashfold=$(echo "$1" | md5sum)
outdir=$(pwd)
mkdir -p "/tmp/youtube-dash/$hashfold"
cd "/tmp/youtube-dash/$hashfold"

# downloading the video stream (MP4 1080p, else fallback 720p)
youtube-dl -f 137/136 -o "/tmp/youtube-dash/$hashfold/%(title)s.zvideo" "$1"

# downloading the audio stream (MP4A-AAC)
youtube-dl -f 140 -o "/tmp/youtube-dash/$hashfold/%(title)s.zaudio" "$1"

for file in *.zvideo; do
	filemtime=$(stat -c %Y "$file")
	ffmpeg -i "$file" -i "${file%.??????}.zaudio" -c:v copy -c:a copy "${file%.??????}.mkv"
	touch -d "@$filemtime" "${file%.??????}.mkv"
	mv "${file%.??????}.mkv" "$outdir/"
	rm -r "/tmp/youtube-dash/$hashfold"
done