After years of purchasing Kindle books, someone has a collection of hundreds of dollars worth of books that they can only read on Amazon’s apps. Change to a Kobo reader, or want to read on an app Amazon doesn’t support, and that library doesn’t come along. The same restriction is true for Audible — years of audiobooks bought that can only be played within Audible’s app. BookFab fixes that by converting eBooks and audiobooks that you buy into open formats that you can use anywhere you want, and it goes one step further: It can convert any text into an audiobook with AI voices.
As a company with long experience in media-conversion software, DVDFab organized BookFab into a series of individual modules within a single application. One is for Kindle, one for Kobo, one for Audible, and one to create audiobooks from text. They are all connected by a DVDFab account. The conversion process entails removing the digital rights management that restricts commercial books to their platforms, and puts the tool in a legal gray area that differs significantly from country to country and depending on how the user uses the converted files.
The Modules Cover
BookFab does not have a single conversion engine, but rather breaks down its functions into modules that the user can select depending on the source. The Kindle module supports reading Amazon’s AZW3, MOBI and current Kindle formats and writing EPUB or PDF. The Kobo module does the equivalent for Kobo’s eBook format. The Audible module converts Audible audiobooks to DRM-free audio. The AI audiobook module is not for converting audiobooks, but for generating them from text. Each module is independent, and a user who only wants Kindle conversion never touches the rest.
The Kindle Workflow
The conversion of a Kindle book follows a specific process. Kindle for PC will download the purchased titles and manage the authentication of the account, and the titles will be stored on the local machine. BookFab then reads the local library, updates the list of books available and the user chooses which books to process. One conversion action decrypts the selected books and outputs them as EPUB or PDF to a selected folder. From there the files can be opened in Calibre, Apple Books, Adobe Digital Editions and the wide variety of e-readers and apps that support standard formats.
Working Inside Calibre
Calibre users benefit from a tighter integration, with a BookFab plugin in Calibre’s toolbar. BookFab is not a standalone program, and the decryption is done automatically when the Kindle book is added to the Calibre library, with the progress displayed within Calibre. The converted, DRM-free book then resides in the Calibre library, where it can be organized, edited and sent to devices without ever leaving the app that most serious eBook collectors use to manage their eBook shelves.
Creating Audiobooks from Texts
The AI part of BookFab does not just convert formats, it makes an audiobook where there was none before. The user enters plain text, a TXT file, or an EPUB and the text-to-speech engine reads it aloud. Plain text and TXT come out as MP3 or OPUS; EPUB files become M4B audiobooks complete with chapter divisions. The library of over 20 AI voices includes various tones and styles, and the narration controls go beyond just speed: expressivity levels, prosody, pause/silence timing, pitch, loudness, and pronunciation rules that correct the way the engine pronounces specific names or unusual words.
Cloning a Voice
If you want a particular voice, but not a preset, the voice cloning feature creates a custom narrator from a brief audio clip. After cloning, that voice reads the imported text, creating audiobooks in a style of narration that is unique to the user, not one of the pre-recorded options.
Formats and Library
The output formats include reading (EPUB and PDF) and listening (MP3, M4A, M4B, FLAC, WAV, and OPUS). The M4B format is important for audiobooks because it includes chapter markers and can keep track of where you are in the book, which is how audiobook apps resume when you’re listening to an audiobook. A built-in library catalogs all of the content that BookFab creates and works with the integrated player to keep track of how far into each book the listener has progressed.
The Cloud Dependency
Some audio enhancement and AI narration features are not processed locally, but on DVDFab’s cloud servers. The cloud method is also the way DVDFab maintains voice quality, and updates model improvements over time, but it also means that the AI features require an internet connection to function — unlike local format conversion.
