Playing Audiobooks on a Car Stereo using Linux

Although there are a few good free sources of shorter audio stories, they're limited, so one quickly starts looking for commercial offerings. The best one I've found so far is Audible.com, or rather, Audible.de. I now have a monthly subscription to Audible, and have bought about ten audiobooks from them.

My car stereo can play CD's and .mp3 files (on usb key or cd-rom), which poses a challenge, since Audible's books are delivered in a proprietary format not handled by most audio devices. Fortunately, The Man has not yet tightened his grip enough to make it impossible to convert from the fully closed proprietary .aax format to a more open one like .mp3.

While there are probably simpler methods out there, the method I'm using is as follows.

• On an Ubuntu system, install wine, and use that to install Audible Manager (not Audible Download Manager), e.g. with 'winetricks audible'.
• Import or download your .aax books with Audible Manager, and verify it can play them. It should, as long as you don't try to pause or rewind or anything... it's good for a straight through play of a book at high quality.
• Install sox and lame, then use a script like the following to begin recording the speaker output to a file:

  #!/bin/sh
  # Parameters - change these to match your book
  NAME=percy2
  LEN_HR=5
  LEN_MIN=11
  # Approximate length in minutes you want it split into pieces of
  # Anything shorter than 20 yields way too many pieces for big books
  TRACK_MIN=20
  
  # find the output channel to record from
  MONITOR=$(pactl list | grep -A2 '^Source #' | grep 'Name: .*\.monitor$' | awk '{print $NF}' | tail -n1)
  # record from it, save result in file $NAME.pcm
  parec --device="$MONITOR" --verbose $NAME.pcm &
  # let the recording go for the desired length
  pid2=$!
  len=`expr '(' $LEN_HR '*' 60 + $LEN_MIN ')' '*' 60`
  sleep $len
  kill $pid2
  # convert from .pcm format to .wav format
  sox -t raw -r 44100 -sLb 16 -c 2 - $NAME.wav < $NAME.pcm
  # convert from .wav format to .mp3 format
  NAME=percy2
  lame $NAME.wav $NAME.mp3
  # Split into tracks, adjusting length slightly for silence
  # (If this were music, with good track breaks, you would
  # use something other than -t -a here.)
  mp3splt -t $TRACK_MIN.00 -a $NAME.mp3
  

• Transfer the .mp3 files to a usb key, insert in car stereo, and enjoy. But please don't share the .mp3 files with anyone else - you paid for them, but you only get to use one copy.

My car stereo can't fast forward or reverse in .mp3 files, so I chop the recordings up into 20 minute segments with mp3splt

I also play on an ipod; that required building eyeD3 0.6.18 (the version that comes with Ubuntu is 0.6.17, which is too old) and using -n %d -N %d to set the track number, and -d 1 -D 1 to set the disc number; without those settings, the ipod will play in random order rather than track order. e.g.

for i in `seq 1 16`
do
   /usr/local/bin/eyeD3 -n $i -N 16 -d 1 -D 1 percy2_$i.mp3
done

Annoyingly, none of the tools on Ubuntu 11.10 seem to be able to initialize or sync to my 3rd gen 4gb ipod shuffle. I had to use iTunes on Windows for that.

Even more annoyingly, iTunes doesn't come with a signed driver, and win 7 64 bits refuses to load unsigned drivers. TS1369 is the appropriate Apple support page, and says "Note: During installation, if a message appears stating that the software you are installing 'has not passed Windows Logo testing' click Continue Anyway to continue installing the drivers." That no longer works; Windows refuses to load the driver. Apple, you suck.

http://www.freeotfe.org/docs/Main/impact_of_kernel_driver_signing.htm describes one's options; the only one that works is pressing F8 at reboot time and selecting "Disable Driver Signature Enforcement". With that, iTunes was able to recognize the iPod.