1  #!/bin/bash
 2  #
 3  # convert-song - Convert an mp3 file to m4a format with reduced bitrate
 4  #
 5  # Converts an mp3 to an m4a (AAC) and reduces the bitrate to 128 kbps.
 6  # Drops video streams (useful for mp3s with embedded artwork).
 7  #
 8  # Usage: convert-song <input.mp3>
 9  #
10  # Requirements: ffmpeg
11  
12  set -euo pipefail
13  
14  input="$1"
15  if ! [ -r "$input" ]; then
16    if ! [ -z "$input" ]; then
17      echo "[error] File not found: $input"
18    else
19      echo "usage: $0 <input mp3>"
20      echo
21      echo "Converts an mp3 to an m4a (AAC) and reduces the bitrate to 128 kbps."
22    fi
23    exit 1
24  fi
25  
26  # -vn drops video on the floor, required for source mp3s with artwork
27  ffmpeg -i "$input" -vn -c:a aac -b:a 128k "${input%.mp3}.m4a"