Audiofy bookchip is a proprietary form of distributing audio books on SD cards, most notably used for Pimsleur language courses. The cards can be played with Audiofy's battery-powered player, or by a computer that can run the software on the card.
Contents
Technical details
Content files are generally named Bcctt.asc where cc is a 2-digit "CD number" and tt is a 2-digit track number. These .asc files use the Ogg container and the Speex codec (generally in ultra-wideband mode), but with a non-standard header marker. A file toc.mau, in a proprietary binary format, indexes these files. The player will attempt to play only files that are mentioned in the toc.mau, and these are checked for integrity; attempts to substitute other Speex-coded audio into their audio sections will result in the spoken message "The bookchip or card you have inserted could not be authenticated" in place of that track, which suggests that the company did not wish to allow end users to load their own content.
Limitations
At this time there is no way for third parties or end users to author bookchips.