Make Your Own iPod-Compatible Audio Books Using Linux

I like music a lot. I think I always have, and I probably always will. I like to be able to listen to good music wherever I go whenever I want. Thanks to the wonders of technology, we have a myriad of portable media devices to choose from. I personally chose an iPod nano. It's a wonderful little toy.

Anyway, as much as I like music, sometimes I feel that my time could be better used doing things more productive than just listening to music. Once I realized I felt this way, I began looking into ways to get my audio books onto my iPod. At first I simply transfered over the MP3s that came straight from the CDs. But I soon realized that this wasn't the most effective use of the iPod's audio book capabilities. So the hunt was on for some good Windows software to convert my MP3 audio books into M4B format for the iPod.

Now, I'm a pretty cheap guy when it comes to paying for software (which is probably one of the main reasons I started using Linux way back when). I found a bunch of different "free" tools that claimed to be able to convert my MP3's, but few of them actually worked well enough for me to stand using them. Eventually, I found a (very round-about) routine that allowed me to turn everything into something my iPod could understand as an audio book. I followed this routine to convert several audio books and transfer them to my iPod. I never actually finished listening to any of them completely.

Last night I started fooling around with converting my DVDs into a format my iPod could understand. When I finally got The Bourne Identity converted properly, I tried to throw it onto my iPod from my wife's Mac. It told me that I would have to erase everything (because I used my own PC to transfer my files before), and I said it was ok. I didn't have any of my original .m4b files around anymore, and so I began looking for ways of creating those audio books (in Linux this time).

It wasn't long before I stumbled upon a particularly interesting post on this exact topic. It requires the use of mp3wrap, mplayer, and faac. Pretty simple, really. Here's what you do:

# mp3wrap outputfilename *.mp3
# mplayer -vc null -vo null -ao pcm:nowaveheader:fast:file=outputfilename.pcm outputfilename_MP3WRAP.mp3
# faac -R 44100 -B 16 -C 2 -X -w -q 80 --artist "author" --album "title" --title "title" --track "1" --genre "Spoken Word" --year "year" -o outputfilename.m4b outputfilename.pcm

Nice and easy, huh? Now to decipher it all.

# mp3wrap outputfilename *.mp3

This command will stitch a bunch of MP3 files into a single MP3. This makes it easier to have a "real" audio book on your iPod.

# mplayer -vc null -vo null -ao pcm:nowaveheader:fast:file=outputfilename.pcm outputfilename_MP3WRAP.mp3

This command converts that one big MP3 file to PCM (uncompressed) format. Somewhere in the output of this command, you will see something like AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample) which comes in handy for the next command:

# faac -R 44100 -B 16 -C 2 -X -w -q 80 --artist "author" --album "title" --title "title" --track "1" --genre "Spoken Word" --year "year" -o outputfilename.m4b outputfilename.pcm

Finally, this command turns the PCM file into an audio book (m4b) file. The 44100, 16, and 2 right after faac all come from that special line in the output of the mplayer command.

As much as I like the command line, I don't like having to remember all of those parameters and options. So I decided to create a utility script (written in Python, of course) to wrap all of these commands into one simple one:

# mp3s2m4b.py BookName mp3s_directory [--quality=0..100] [--artist="artist"] [--album="album"] [--title="title"] [--genre="genre"] [--year=year] [--track=number]

While this might still seem too complex for pleasure, it does reduce a lot of the typing involved with the other three commands. All of the thingies in square brackets (like [--quality=0..100]) are optional. My script runs the commands mentioned previously in order, and suppresses all of the scary output.

I've used my script 4 or 5 different times so far, and it seems to work great. You may download it here.