ADX (file Format)

ADX (file Format)

ADX is a lossy proprietary audio storage and compression format developed by CRI Middleware specifically for use in video games, it is derived from ADPCM. Its most notable feature is a looping function that has proved useful for background music in various games that have adopted the format, including many games for the Sega Dreamcast as well as some PlayStation 2, GameCube and Wii games. One of the first games to use ADX was Burning Rangers, on the Sega Saturn. Notably, the Sonic the Hedgehog series from the Dreamcast generation up to at least Shadow the Hedgehog have used this format for music and voice recordings.

On top of the main ADPCM encoding, the ADX toolkit also includes a sibling format, AHX, which uses a variant of MPEG-2 audio intended specifically for voice recordings and a packaging archive, AFS, for bundling multiple ADX and AHX tracks into a single container file.