This guide is specifically for optimal Audiobook experience using Plex, which in it's current state only quasi-supports audiobooks. This is my method for processing large libraries with bad/missing tags as quick as possible while getting the most metadata into Plex in the least amount of time. I'll be doing a deep dive into some advanced features of the tools available to us in order to get a nice, clean, and functional UI. This guide is meant to serve as a framework for fully utilizing metadata.  Everything is customizable, and easy to change. While focused on Plex, if you follow the tagging and file processing steps you will also be compatible with Booksonic and AudiobookShelf servers.

Note: This guide targets and has been tested on Windows systems. Most of it also works on Linux/Mac but the Mp3tag Audible WebSource script only works on Windows. For workarounds see issue #2.

• Goal
• Working Folders
• (Optional) Automatically copy untagged Audiobook files to a temp folder
• (Optional) Automatically convert mp3 audiobooks to chapterized M4B
• Configure Mp3tag
  • Set the default folder
  • Download my example configuration files to Mp3tag's Appdata directory
  • Edit the newly copied config files with your specific paths
  • Test
• Configure Plex
  • Install Plex Audiobook Agents
  • Configure Metadata Agent in Plex
  • Create Audiobook Library in Plex
• Workflow
• Tips!
• Tags that are being set
• Players
• Notes

Show as much metadata as possible in Plex & Booksonic.  Filter/browse/search by Narrator, Author, Genre, Year, Series, Rating, or Publisher.  Show Album Covers and Summary's. Make the organizing and tagging as quick and painless as possible. We need to do these 4 general steps:

0. (Optional) Convert mp3's to chapterized m4b.
1. Ensure the ALBUM and ALBUMARTIST (or ARTIST) tags are set and correct.
2. Install the Audnexus Audible Metadata Agent in Plex.
3. Use a 3rd party Audiobook player app such as BookCamp or Prologue.

I plan on having a seprate walkthrough that will take you through backing up your Audible .aax files, and converting them to chapterized .M4B files. This guide will work for both mp3 and m4b files, but I prefer chapterized m4b's. Plex handles M4B metadata better than mp3's, some third party players like Prologue and BookCamp can handle the M4B chapter splits and names, and generally having less files helps plex run smoother.

In the mean time please check out this awesome guide here: http://checkthebenchmarks.com/2019/09/23/why-you-should-manage-your-own-audible-library/

For some more Software resources for Audible-centric audiobook management, including removing DRM from Audible files check out @rmcrackan's AudiobookHub

Now that you have your files, let get them in a format Plex can handle so we can stream our whole library with our firends and family.

I have 3 working directories for my Audiobooks:

• ~/Original Folder where I keep the un-altered original audio Files
• ~/temp Folder where I copy the audio files that need to be processed, this is the folder Mp3tag will open by default
• ~/Audiobooks Folder where I archive my properly tagged files in the proper folder structure, this is the folder I point Plex at

Anywhere these folders are referenced, make sure to update to your specific paths

Best Practice: Tag your files before adding them to Plex.

Optional: This step is only required if you want to preserve the original unedited Audiobook files. This is required if you are seeding torrents, for example from librivox.org. That said, this is a recommended step for everyone, just incase something goes horribly wrong with Mp3tag or copying files.

/original
|
+-- /Book1
|   |
|   +-- book1.mp3 (Date: T-1min)
|   +-- book1cover.jpg (Date: T-1min)
|
+-- book2.m4b (Date: T-2min)
+-- book3.m4b (Date: T-1Hr)

RUN SCRIPT (every 2min)

/temp
|
+-- book1.mp3
+-- book2.m4b

This will automatically copy untagged books from \Original to \temp, which we will set as the default folder Mp3tag opens to, so all you have to do is open Mp3tag and any books that need processing will be automatically loaded. Expand and follow one of the options below for your OS.

#!/bin/sh
find /full/path/to/Original/ -type f \( -iname \*.m4b -o -iname \*.mp3 -o -iname \*.mp4 -o -iname \*.m4a -o -iname \*.ogg \) -mmin -3 -exec cp -n "{}" /full/path/to/temp/ \;

Let's face it, Large Libraries Sink Ships. Everything runs quicker, and smoother, the lower the total number of files there are to scan. Let's say you have 5000 books. If they were mp3's then you would be looking at least 100,000 files, vs 5000 m4b's. M4b's can also hold chapter data, and generally the metadata works better with Plex over mp3's.

If you use both Linux and Windows, I have a Linux script that watches your /original folder for newly added mp3 audiobooks and converts them to M4b files with chapters separated by mp3 file. It's pretty slick.

• Creating and Installing auto-m4b-tool script guide
  • https://github.com/seanap/Auto-M4B-Tool#m4b-tool-automation

• Install, or Upgrade Mp3tag to the latest version

• Tools > Options > Directories
• Put the full path of the \temp directory with your untagged books in Favorite directory:
• CHECK start from this directory
  

• Download my repo by clicking Here.
  • Alternatively, click the green 'Code' dropdown button at the top of this Github page and select “Download Zip”.
• The Mp3tag folder will be located in the zip archive. Unzip the archive.
• Open the Plex-Audiobook-Guide folder
• Copy (or move) the Mp3tag folder to C:\Users\your-username-here\Appdata\Roaming folder
  • Click Yes to merge/overwrite files

• Right click the following provided config files and OPEN WITH Notepad++
  • %APPDATA%\Mp3tag\data\action\&1 Rename Relocate Extras Title.mta Update lines 3, 15, 22 with the path to your Plex \Audiobook folder
  • %APPDATA%\Mp3tag\export\001 Generate.mte Update line 1 with your windows username C:\Users\your-username-here\...
  • %APPDATA%\Mp3tag\export\desc.mte Update line 1 with the path to your Plex \Audiobook folder
  • %APPDATA%\Mp3tag\export\reader.mte Update line 1 with the path to your Plex \Audiobook folder

$filename(desc.txt,utf-8)
%comment%

$filename(reader.txt,utf-8)
%composer%

• Put an audiobook file for testing in your \temp folder
• Open Mp3tag and select all files for that book
• Ctrl-k and set/fix the Track Numbering if applicable
• Click the Web Sources drop down button, select Audible.com > Search by Album
  
• Click the Action drop down button, select the &1 Rename Relocate Extras Title Action
  

Note: After selecting the Web Source manually for the first time we can then use the keyboard shortcut ctrl+shift+i to call it moving forward. Likewise the action script can be called using alt+a 1.

Follow the Instructions here

• https://github.com/djdembeck/Audnexus.bundle

• Go to Settings > Agents > Artist > Audiobooks Put Audnexus above Local Media Assets
  
• Go to Settings > Agents > Albums > Audiobooks Put Audnexus above Local Media Assets
  

• General select Music
• Add folders browse to your Audiobook folders
• Advanced set the following:
  • Agent = Audnexus Agents
  • Keep existing genre's - The new agent pulls 4-6 meaningful genres but if you want to keep your existing CHECK this box
  • Album sorting - By Name (This uses the Albumsort tag to keep series together and in order)
  • UNCHECK Prefer Local Metadata
  • CHECK Store track progress
  • UNCHECK Author Bio
  • Genres = None
  • Album Art = Local Files Only

Now that the hard part of setting everything up is out of the way, this is what your typical workflow will look like moving forward:

Mp3tag can only work on one audiobook at a time.

1. Ctrl-a or, Select All tracks of an Audiobook
2. Ctrl-k Set/fix the track numbers
3. Ctrl-shift-i or Click the Web Source (quick) button
4. Alt-a 1 or Click the Action drop down menu
   
5. This does not set the TITLE tag for multifile books. Plex uses TITLE as the Chapter Name. There are two easy options to set this:
   • Click the Filename - Tag button, Format String= %Title%, this will set the filename as the Chapter name.
   • Click the Action drop down, select Chapter %track% which will give you a generic "Chapter 1, Chapter 2, ..."

• There are two key board shortcuts that call the Audible Web Source script, which one to use depends on if the Album and Artist tags exist or are accurate.
  • Ctrl-i - Use if there are no tags, or if the Album/Artist tags are incorrect or contain junk data that will effect the Audible search. This shortcut will bring up the search and allow you to put exactly what you want to search Audible with, try to keep it as simple as possible with only Album and Author, you can also put the ASIN number in this dialog box to search for a specific book on Audible.
  • Ctrl-Shift-i Use if the Album and Artist tag look to be ok, this will bypass the search input dialog box and bring you straight to the results.
• If the Author is also the Narrator make sure you delete the duplicate entry in the Artist field. The script automatically combines the Author and Narrator (ex. Peter Clines, Ray Porter) in the Artist tag, which Plex uses as a "All Artists on this track" tag. Combining these tags for the Artist helps when searching Plex.
• Try to only keep 1 cover file in the tag, when the script asks if you want to save the existing cover, say "No". If you happen to like the included cover over Audibles, in the Tag Review screen you can click the "Utils" button (bottom left) and UNCHECK "Save Image to Tag", but make sure you remember to recheck this on the next book.

I did a lot of digging into ID3 standards and this was the best way I could come up with to shoehorn Audiobook metadata into mp3 tags. It certainly isn't perfect, but it does work very nicely for Plex and other Audiobook apps. These can be changed to fit your particular style by editing the Audible.com#Search by Album.src file in Notepad++.

*I would prefer Original Pub. year, but Audible is really bad at providing this data
**Custom Tags used as placeholders, To view this tag Tools>Options>Tag Panel>New

• iOS
  1. BookCamp ($12/yr) - Connects to Plex, Cross Platform, NEW! Still in Beta
  2. Prologue ($5) - Connects to Plex,
  3. Play:Sub - Connects to Booksonic
• Android
  1. BookCamp ($12/yr) - Connects to Plex, Cross Platform, NEW! Still in Beta
  2. Chronicle (Opensource) - Connects to Plex, limited functionality but works well
  3. PlexAmp (Plexpass) - Connects to Plex, Official Plex audio app, Music focused player, easy to lose your place.
  4. Booksonic - Connects to Booksonic, has a few quirks but it works
  5. Smart - Local media files only, but tons of great Audiobook specific features

Once you have mp3tag, Audiobook metadata agent, and Plex configured the work flow becomes pretty quick and painless, especially when using keyboard shortcuts.

Following this guide will also give you everything you need for a properly organized AudiobookShelf and Booksonic server. While Plex doesn't really care about your folder structure beyond /Audiobook/Author/Book/book.mp3, Booksonic exclusively uses folder structure for it's organization and it also looks for cover.jpg/desc.txt/reader.txt files (automatically created with the Action script) for additional metadata.

I currently use BookCamp ($12/yr), it is miles better than the Plex app and PlexAmp and works on both iOS and Android, but if you are on iOS then Prologue is the preferred option.