Audible to MP3

It's frustrating when you purchase an audio book on Audible but can then only play it back from their apps - which isn't possible if you want to put it on a basic MP3 player to take jogging, cycling, etc.

To get around this you can strip away the DRM using your activation code. So this isn't cracking the code but just removing it, meaning you need to know your own 4bit Audible key.

Steps:

1) download the .aax file from your Audible account

2) use this tool to find your key  (drag the .aax file to this page and copy the key it returns)

https://audible-tools.github.io/ 

3) Install ffmpeg on your PC and then run this command:

ffmpeg -activation_bytes your-key-here -i input.aax -vn -c:a copy output.mp4

where you switch your-key-here to the value you got from the web tool, and the input.aax to the filename of the .aax you downloaded. This generates an output MP4 file in a few seconds which is free from the DRM. 

Now you can move it to any suitable player! 

---

Shell script to chop .aax into mp3 chapters

#!/bin/bash
# Author: http://crunchbang.org/forums/viewtopic.php?id=38748#p414992
# m4bronto
#     Chapter #0:0: start 0.000000, end 1290.013333
#       first   _     _     start    _     end
while [ $# -gt 0 ]; do
ffmpeg -i "$1" 2> tmp.txt
while read -r first _ _ start _ end; do
  if [[ $first = Chapter ]]; then
    read  # discard line with Metadata:
    read _ _ chapter
    
    ffmpeg -vsync 2 -i "$1" -ss "${start%?}" -to "$end" -vn -ar 44100 -ac 2 -ab 128  -f mp3 "$chapter.mp3" </dev/null
  fi
done <tmp.txt
rm tmp.txt
shift
done