Create YouTube MKVs from FLAC album

CreateMKVs.sh

#! /bin/bash
cover=./cover.jpg
if [ ! -f "$cover" ]; then
	cover=./cover.png
fi
if [ ! -f "$cover" ]; then
	echo "No cover image found."
	exit
fi

for f in *.flac
do
	time=$(date +%s)
	duration=$(ffprobe -i "$f" -show_entries format=duration -of csv=p=0 -v quiet)
	album=$(ffprobe -i "$f" -show_entries format_tags=album -of csv=p=0 -v quiet)
	title=$(ffprobe -i "$f" -show_entries format_tags=title -of csv=p=0 -v quiet)
	track=$(ffprobe -i "$f" -show_entries format_tags=track -of csv=p=0 -v quiet)
	disc=$(ffprobe -i "$f" -show_entries format_tags=disc -of csv=p=0 -v quiet)
	if [ -z "$disc" ]; then
		final="$album — $track. $title"
	else
		final="$album — $disc.$track. $title"
	fi
	printf "Track data:\n\tfile: $f\n\ttitle: $title\n\talbum: $album\n\tduration: $duration\n\tdisc: $disc\n\ttrack: $track\n\tfinal title: $final\n"
	echo "Transcoding $final..."
	ffmpeg -i "$f" -loop 1 -t "$duration" -i $cover -c:a copy -c:v libvpx-vp9 -s 1080x1080 -v quiet "$final".mkv
	time=$(($(date +%s)-time))
	echo "Took $time seconds."
done

As YouTube does not support lossless audio, I thought it would be best to demonstrate what I believe the best possible case for uploading a lossless format to YouTube, as a copy of the .flac file with a repeated image, ideally the album cover.

Matroska is NOT listed on the list of supported YouTube formats, though WebM, essentially a subset of the Matroska container, is listed. Even though this is the case, Matroska files CAN be uploaded to YouTube, including ones with FLAC encoded audio.