Convert .m3u to .audpl (Audacious playlist file)

m3u2audpl.sh

#!/bin/bash
############################################################################################
# m3u2audpl.sh
#
# Creates an Audacious playlist,
# pre-indexed faster than Audacious does it over network mounts
# Supported formats: basic m3u, extended m3u.
#
# Usage:
#  1. Create an empty playlist in Audacious
#  2. Shut down Audacious
#  3. Check which filename it got:
#     ls -ltr ~/.config/audacious/playlists | tail -1
#  4. ./m3u2audpl.sh /full/path/to/m3ufile > ~/.config/audacious/playlists/NNNN.audpl
#
# For best results, configure Audacious as follows:
#  - Settings > Song Info > Guess missing metadata from file path
#  - Settings > Song Info > Do not load metadata for songs until played
#
# Known issues:
#  - .audpl song durations are always up to 1 second higher due to lack of m3u ms precision
############################################################################################

set -e

# Source: https://gist.github.com/cdown/1163649
urlencode() {
  # urlencode <string>
  old_lc_collate=$LC_COLLATE
  LC_COLLATE=C

  local length="${#1}"
  for (( i = 0; i < length; i++ )); do
      local c="${1:i:1}"
      case $c in
          [a-zA-Z0-9/.~_-]) printf "$c" ;;
          *) printf '%%%02X' "'$c" ;;
      esac
  done

  LC_COLLATE=$old_lc_collate
}

if [ -z "$1" ]; then
	echo "Usage: $0 /full/path/to/m3ufile" >&2
	exit 1
fi

M3UFILE="$1"

if ! [ -f "$M3UFILE" ]; then
	echo "File not found: $M3UFILE" >&2
	exit 1
fi

IS_EXTM3U=false
if [ "$(head $M3UFILE | grep '^#EXTM3U$')" ]; then
	IS_EXTM3U=true
fi

# OUTPUT: playlist title
echo "title=$(urlencode "Playlist from $(basename $M3UFILE) @ $(date '+%Y-%m-%d %H:%M:%S')")"

NLINES="$(wc -l $M3UFILE | awk '{print $1}')"
LINENUM=0
INFOLINE=

cat "$M3UFILE" | grep -vE '^(#EXTM3U)?$' | while read LINE
do
	# Output progress
	LINENUM=$[$LINENUM +1]
	echo -ne "$LINENUM/$NLINES\r" >&2

	if [ "$IS_EXTM3U" == "true" ] && [ "$(echo "$LINE" | grep '^#')" ]; then
		INFOLINE="$LINE"
		continue
	fi

	AUDFILE="$LINE"
	if [ "${LINE:0:1}" != "/" ]; then
		M3UDIR="$(dirname "$M3UFILE")"
		if [ "$M3UDIR" == "." ]; then
			M3UDIR="$(pwd)"
		fi
		AUDFILE="$M3UDIR/$LINE"
	fi

	PATH_ENCODED="$(urlencode "$AUDFILE")"

	# OUTPUT: audio file path
	echo "uri=file://$PATH_ENCODED"

	if [ "$IS_EXTM3U" == "true" ]; then
		TITLE="$(echo "$INFOLINE" | sed -r 's/^#EXTINF:[0-9]*( [^,]+)?,(.*)$/\2/g')"		
		DURATION="$(echo "$INFOLINE" | sed -r 's/^#EXTINF:([0-9]*).*$/\1/g')"		
	fi
	if ! [ "$TITLE" ]; then
		TITLE="$(basename "$AUDFILE")"
	fi

	# OUTPUT: song title
	echo "title=$(urlencode "$TITLE")"

	# OUTPUT: duration
	[ "$DURATION" ] && echo "length=$((DURATION+1))000"
done