misc-scripts/albumsetup

#!/bin/sh
set -euf

EXT="flac" # default
NL="
"

errecho() { echo "$*" >&2 ; }
die() { errecho "$*" && exit 1 ; }
clean() {
	trap 'exit' INT HUP QUIT EXIT
	[ -f "${DEFAULT_PICTURE:-}" ] && rm -f "$DEFAULT_PICTURE"
	[ -f "${JSON:-}" ] && rm -f "$JSON"
}

# wrapper to grab a specific tag from flac/opus/mp3
grabtag() {
	case ${1##*.} in
		flac) metaflac --show-tag="$2" "$1" | cut -d '=' -f 2- ;;
		opus) opusinfo "$1" | awk -v RS='\n\t' -v FS='=' -v OFS='' "/^$2=/"'{$1=""; print $0}' ;;
		mp3)
			case "$2" in
				ARTIST) id3 -q '%_a' "$1" ;;
				ALBUM) id3 -q '%_A' "$1" ;;
				TRACKNUMBER) id3 -q '%_###T' "$1" ;;
				TITLE) id3 -q '%_t' "$1" ;;
				ALBUMARTIST) id3 -2 -q "%|%{TPE2}||%{TXXX:ALBUM ARTIST}|?" "$1" ;;
				*) printf 'unknown tag used for mp3' ;;
			esac
			;;
		*) die 'unknown filetype'
	esac
}

# grab track info, make tracknumber 3-padded just in case for long albums
# (no album has > 999 tracks. I think.)
grabinfo() {
	DURATION="$(ffprobe -v quiet -of csv=p=0 -show_entries format=duration "$1")"
	ARTIST="$(grabtag "$1" ARTIST)"
	ALBUM="$(grabtag "$1" ALBUM)"
	TITLE="$(grabtag "$1" TITLE)"
	TRACKNUMBER="$(printf '%03d' "$(grabtag "$1" TRACKNUMBER)")"
}

ffconv() { 
	IFS=" "
	ffmpeg ${VERBOSE--loglevel error} -y -loop 1 -framerate 4 -f image2 -i "$1" ${FULLALBUM:+-safe 0 -f concat} -i "$2" \
		-t "${TOTALTIME:-$DURATION}" \
		-pix_fmt yuv420p \
		${acopy:--c:a libopus -b:a 256k} \
		-r 4 \
		-b:v 500k \
		-c:v libvpx \
		-cpu-used -5 \
		-deadline realtime \
		"$3"
	errecho "Successfully converted $2"
}

extract_cover() {
	set +e
	tmpimg="$(mktemp -u -t ALBUMSETUP_COVER.XXXX)"
	case ${1##*.} in
		flac) metaflac --export-picture-to="$tmpimg" -- "$1" ;;
		opus) opustags --output-cover "$tmpimg" -- "$1" ;;
		mp3) ffmpeg -i "$1" -map "0:v:0" -c:v copy "$tmpimg" ;;
		*) die 'unknown filetype'
	esac
	printf '%s' "$tmpimg"
	set -e
}

# GET OPTIONS #

SONG="" FULLALBUM="" BANDCAMP=""
OUTDIR="/tmp/albumsetup/${PWD##*/}"
while getopts :ovd:e:p:s:b: OPT; do
	case "$OPT" in
		o) FULLALBUM=1 ;;
		v) VERBOSE="" ;; # can use ${var-rep} for this
		d) cd "$OPTARG" && OUTDIR="${OUTDIR%/*}/${PWD##*/}" ;;
		e) EXT="$OPTARG" ;;
		p) tmpimg="$OPTARG" ;;
		s) SONG="$OPTARG" && OUTDIR="${OUTDIR%/*}" ;; # individual song
		b) BANDCAMP="$OPTARG" ;; # bandcamp link to extract data
		*) die "albumsetup: invalid option: -$OPTARG" ;;
	esac
done
shift "$((OPTIND - 1))"

[ ! -f "$tmpimg" ] && die "Default image not specified!"

mkdir -p "$OUTDIR"

# convert cover image. it has to be wider than 1:1 so youtube doesn't convert it to a short
# if image is wider than 1:1, just resize height. if not, pad with black
DEFAULT_PICTURE="$OUTDIR/ALBUMSETUP_IMG.png"
magick convert "$tmpimg" -resize 1280x720 -background black -gravity center -extent 722x720 "$DEFAULT_PICTURE"

trap 'clean' INT HUP QUIT EXIT
[ "$EXT" = "opus" ] && acopy="-c:a copy" # copy audio codec if opus since output codec is opus

# INDIVIDUAL SONG #
if [ "$SONG" ]; then
	grabinfo "$SONG"
	ffconv "$DEFAULT_PICTURE" "$SONG" "$OUTDIR/SONG ${ARTIST%%/*} - ${TITLE%%/*}.webm" # substitution mods are to not create directories

# CONTINUOUS VIDEO OF WHOLE ALBUM #
elif [ "$FULLALBUM" ]; then
	TOTALTIME=0 # keeping track of timestamps
	IFS="$NL"
	for f in $(fd -d 1 -e "$EXT"); do
		grabinfo "$f"

		# make timestamp
		printf '%02d:%02d:%02d - %s\n' \
			"$((${TOTALTIME%%.*} / 3600))" "$((${TOTALTIME%%.*} % 3600 / 60))" "$((${TOTALTIME%%.*} % 60))" \
			"$ARTIST - $TITLE" >> "$OUTDIR/metadata.txt"
		# add to total time, but this is as a float remember that
		TOTALTIME="$(echo "$TOTALTIME + $DURATION" | bc)"
		# build ffmpeg concat metadata
		sf="$(printf '%s' "$f" | sed "s/'/'\\\\''/g")" # make safe filename for ffmpeg concat; replace all ' with '\''
		echo "file '${PWD}/$sf'" >> "$OUTDIR/ffmpeg_tracklist.txt"
	done
	[ ! -f "$OUTDIR/ffmpeg_tracklist.txt" ] && die "No files found!"
	ffconv "$DEFAULT_PICTURE" "$OUTDIR/tracklist.txt" "$OUTDIR/$ARTIST - $ALBUM.webm"
	rm "$OUTDIR/ffmpeg_tracklist.txt"

# INDIVIDUAL TRACKS FOR FULL ALBUM (default) #
else
	IFS="$NL"
	for f in $(fd -d 1 -e "$EXT"); do
		grabinfo "$f"

		# metadata print
		printf '%s %s - %s - %s\n' "${TRACKNUMBER:-000}" "${ARTIST:-unknown artist}" "${ALBUM:-unknown album}" "${TITLE:-unknown title}" >> "$OUTDIR/metadata.txt"
		# try making auto pic
		tmpimg="$(extract_cover "$f")"
		PICTURE="$tmpimg"
		[ ! -f "$PICTURE" ] && PICTURE="$(fd -e jpg -e png "^track$TRACKNUMBER")"
		[ ! -f "$PICTURE" ] && PICTURE="$DEFAULT_PICTURE"
		errecho "Converting $f"
		ffconv "$PICTURE" "$f" "$OUTDIR/$TRACKNUMBER ${ARTIST%%/*} - ${TITLE%%/*}.webm"
		[ -f "$tmpimg" ] && rm -f "$tmpimg"
	done
	[ ! -f "$OUTDIR/metadata.txt" ] && die "No files found!"
	# sort by correct track numbers then remove track numbers later
	sort -o "$OUTDIR/metadata.txt.sorted" "$OUTDIR/metadata.txt"
	while read -r line; do
		echo "$line" | cut -d ' ' -f 2-
	done <"$OUTDIR/metadata.txt.sorted" >"$OUTDIR/metadata.txt"
	rm "$OUTDIR/metadata.txt.sorted"
	
	# Bandcamp check and info retrieval
	if [ "$BANDCAMP" ]; then
		JSON="$(mktemp -t "ALBUMSETUP_JSON.XXXX")"
		curl -L -s -o - "$BANDCAMP" | pup 'script[type="application/ld+json"]' 'text{}' > "$JSON"
		albumartist="$(jq -r '.byArtist.name' < "$JSON")"
		date="$(jq -r '.datePublished' < "$JSON")"
		date="$(date -d "$date" -u +'%Y-%m-%d')"
		desc="$(jq -r 'if (.description) then .description | gsub("[\\r]"; "") else empty end' <"$JSON")"
		creds="$(jq -r 'if (.creditText) then .creditText | gsub("[\\r]"; "") else empty end' <"$JSON")"
		{
			printf '%s - %s\n\n' "$albumartist" "$ALBUM"
			cat "$OUTDIR/metadata.txt"
			printf '\nReleased %s\nDOWNLOAD: %s\n\n' "$date" "$BANDCAMP"
			[ "$desc" ] || [ "$creds" ] && printf '%s\n' 'Release notes:'
			printf '%s\n\n%s' "$desc" "$creds" | sed -e 's/</‹/g'
		} > "$OUTDIR/metadata2.txt"
		mv "$OUTDIR/metadata2.txt" "$OUTDIR/metadata.txt"
		rm -f "$JSON"
	fi
fi