audiobook_tool README

History

I took a job where I was driving 100 miles every day. The audiobook became my new best friend.

A quick google search showed that there weren't any nice linux tools to create audiobooks, so I started hacking some scripts together. They were hacky, but I only had to use them every few weeks when I wanted a new audiobook.

After listening to dozens of books, I started collecting a list of features that I wanted my authored books to have.

An audiobook-interested coworker knew how to create chapters for mp4 books, and I started adding scripts to get chapter goodness.

There were a mess of scripts and really they were only useful to me. I had different scripts for making books from cds, mp3s, etc, and I eventually combined them into an encompassing tool to make them easier to use. This way I didn't have to re-learn my hacky scripts every time I used them.

Through more and more usage as well as input from the previously mentioned coworker, the tool evolved to something useful for at least one other person.

This other person (we may as well identify him: Joel) started adding cool features so I eventually posted the code to ease collaboration.

Containers / Codecs

For Apple devices, m4b probably works the best. Most Android players will also support m4b.

For internet friendly (ie: no patents/royalties) codecs and containers, mka, ogg, and opus are preferred. I think mka (Matroska) is the best overall generic container, although it's not terribly popular for audiobooks (nor audio only for that matter). Opus works really well for low bitrate speech.

Now that the ogg container has a formal extension for chapters, opus and ogg work pretty well also. But, the tooling for vorbis and opus don't seem to be interchangeable, even though they both use the ogg container (hence the preference for Matroska). Opus is a more versatile codec than vorbis in that it works well for low and high bitrates.

mp3 support could probably be enhanced to support chapters and metadata via ID3v2 tags, but this has not been a priority.

Players

Android

Listen

• m4b: all metadata supported

• mka: does not show up in list

• webm:

  • [-] title
  • [?] author
  • [-] cover art

• opus:

  • title works
  • [?] author
  • [-] cover art

• ogg:

  • title works
  • [?] author
  • cover art

Voice

• m4b: all metadata supported

• mka: all metadata supported (my preferred container/codec)

• webm: all metadata supported

• opus: all metadata supported

• ogg: all metadata supported

Data CD

Many cd players, particularly in automobiles, support playing mp3 files. The recommended layout seems to be to have a "Title" folder containing files. The files can each have metadata tags, which can be displayed.

Easytag is a nice way to set the metadata. For each file:

• Artist: Author
• Album: Title
• Title: Chapter Name

The 2013 Ford Fusion supports mp3 and wma. What other formats are common for automobiles?

Splitting File

Sometimes it's helpful to split an audio file into multiple files. This can be done with Audacity:

https://manual.audacityteam.org/man/splitting_a_recording_into_separate_tracks.html

If the source file is large, exporting to flac works well (ie: wav files seem to have a 6GB filesize max)

Other projects

• http://audiotools.sourceforge.net/ (doesn't seem to handle chapters)