A simple shell script for downloading audio from YouTube and saving to MP3 format, with ID3 information.

yt2mp3

#!/bin/bash
# Simple shell script for downloading audio from YouTube as .mp3 file
# Requires:
#     * youtube-dl (http://rg3.github.io/youtube-dl/)
#     * id3tag (Ubuntu libid3 package, based on http://id3lib.sourceforge.net/)

if [ -z "$1" ]; then
  echo "Usage: yt2mp3 <file>"
  echo "File supplied must have a list of URLs to YouTube videos and ID3"
  echo "information, comma-separated."
  echo "For example: http://youtube.com/whatever,Title,Artist,Album"
  exit
fi

IFS=$'\r\n'
VIDEOS=($(cat $1))
for LINE in "${VIDEOS[@]}"
do
        # Parse the song file:
        URL="$(echo ${LINE} | sed -ne 's/^\(.*\),\(.*\),\(.*\),\(.*\)/\1/p')"
        TITLE="$(echo ${LINE} | sed -ne 's/^\(.*\),\(.*\),\(.*\),\(.*\)/\2/p')"
        ARTIST="$(echo ${LINE} | sed -ne 's/^\(.*\),\(.*\),\(.*\),\(.*\)/\3/p')"
        ALBUM="$(echo ${LINE} | sed -ne 's/^\(.*\),\(.*\),\(.*\),\(.*\)/\4/p')"
        FILE="${ARTIST} - ${TITLE}"

        # Download the file:
        echo -ne "Downloading ${TITLE}..."
        x=~/.youtube-dl-$RANDOM-$RANDOM.flv
        youtube-dl --output=$x --format=18 "${URL}"  > /dev/null 2>&1

        # Convert to MP3:
        echo -ne "Converting to mp3..."
        avconv -i $x -acodec libmp3lame -ac 2 -ab 128k -vn -y "${FILE}.mp3"  > /dev/null 2>&1
        rm $x

        # Add ID3 info:
        echo -ne "Adding ID3 info..."
        id3tag -s "${TITLE}" -a "${ARTIST}" -A "${ALBUM}" "${FILE}.mp3" > /dev/null 2>&1
        echo "Done!"
done