AVCHD (Advanced Video Coding High Definition) is a file-based format for the digital recording and playback of high-definition video. Developed jointly by Sony and Panasonic, the format was introduced in 2006 primarily for use in high definition consumer camcorders.
The maud file extension is associated with the Amiga MAUD audio format, developed by Electronic Arts and Commodore in 1985. The MAUD is used for an 8 or 16 bit Amiga sound format. Most likely obsolete.