What is an AAX file?
The .aax file extension designates a specialized format for digital audiobooks, developed and pioneered by Audible—a leading American online audiobook and podcast service owned by Amazon.com Inc. As the enhanced successor to the older AA file format, AAX files offer a significantly richer, multimedia experience. These files are the standard distribution format for platforms like AAudible; Audible Kids, and the iTunes Store. Unlike basic audio files, AAX files are sophisticated digital multimedia containers that can integrate features such as embedded graphics, video clips, interactive bookmarks, and a precise video timeline. This robust functionality makes the AAX format a particularly engaging and suitable choice for children’s content, including interactive Picture Books and Graphic Novels, providing a more immersive and useful listening and viewing experience.
AAX file format
AAX is an Audiobook file format, which is a M4B file with high quality due to its variable-bitrate and encrypted with DRM (Digital Rights Management) encryption algorithm. Majority of ebooks are encoded at 64 kbit/s, 22.050 kHz, stereo, some are as low as 32k, mono and radio plays are usually encoded at 128kbit/s and 44.1 kHz. The audio of AAX file format is encoded in AAC format (variable quality).
AAX File Format Specifications
The detail about AAX file format quality specs available at audible is shown below:
- Bitrate: 32 - 128 kbit/s
- Sample rate: 22.050 - 44.10 kHz
- Bit Depth: Unknown
- Channel: Mono or stereo
- MBytes/hour: 28.8
- Container: MPEG-4 Part 14
- Quality description: AAC sound
Digital rights management (DRM)
Audible file formats encapsulate the encoded sounds but they also include the prevention for un-authorized playbacks by means of an Audible username and password, which can be used by-default on up to four computers and three smartphones at a time. Schools and libraries may be offered different types of licenses. The DRM is responsible to control:
- The un-authorized user access
- Burn a limited number of CDs for unrestricted playback
- Enable Audible content for limited number of devices But you can still find many other software tools which can easily bypass the DRM control of Audible. Audible is now offering DRM-free titles for content writers. The FFmpeg 2.8.1 or greater versions can play .aax file formats natively.
Chapterized Structure and Rich Metadata
An AAX file is a structured container, not just a long audio stream.
Chapter Markers: The file contains embedded chapter markers, allowing listeners to navigate through the book effortlessly, skipping forward or backward between chapters within any supported app.
Metadata: Detailed information is embedded within the file, including the book title, author, narrator, publisher, copyright information, and cover art. This metadata is displayed by the playback software.
FAQ
Q1: How is an AAX file different from an AA file?
A: AAX is the newer format, offering higher quality audio (AAC codec) and more advanced DRM compared to the older, lower-quality AA format.
Q2: Can I play an AAX file in VLC or Windows Media Player?
A: No, standard media players cannot play AAX files due to the DRM protection. They must be played in authorized apps like the Audible app or iTunes.
Q3: Is it legal to convert an AAX file to MP3?
A: Converting AAX files by removing their DRM protection is a violation of Audible’s Terms of Service and copyright law, as it circumvents the copyright protection measures.
Q4: What do AAX, AAX+, and AAX++ mean?
A: These denote the audio quality level: AAX is standard quality, AAX+ is high quality (~128 kbps), and AAX++ is the highest quality (~256 kbps).
Q5: I bought an audiobook; do I own the AAX file forever?
A: Yes, any audiobook purchased from Audible remains permanently in your library, and you can re-download the AAX file at any time, even if you cancel your membership.
