SMAF stands for "Synthetic music Mobile Application Format", and is a data format specified by Yamaha that defines multimedia content for use on hand-held portable devices, such as mobile phones and PDAs. The most common application of SMAF is the creation of ring tones for mobile phones; however, the full specification defines support for graphics too.
The Yamaha MA-1, MA-2, MA-3, MA-5, and MA-7 sound chips feature in many of today's mobile phones. Any device incorporating one of these chips is capable of playing SMAF sound files.
A variety of hardware and software authoring tools are available to developers of content for mobile phones and other devices. These tools can be used to create SMAF data files (.mmf files). The simplest way of doing this is to convert existing sound files in other formats using a software conversion tool. Files in the .wav or .mid (standard MIDI) formats are two examples of audio files which can be converted in this way.