The Nintendo Ultra64 Sound Format (USF) is a file format to store sound data (akin to SPC from the Super NES) ripped directly from a Nintendo 64 video game.
USF files are generated manually from the video game's ROM by isolating the program code responsible for playing music, plus the stored music data. The rest of the bits of the ROM are zeroed, and compression is then applied to reduce the file size by a factor of about 10-20. The ripping process is very manual-intensive because the Nintendo 64 has no standard format in which the music playback code and music data are stored in the ROM. USF files can be played back in Winamp through the use of an appropriate plug-in, such as 64th Note .
The USF does not use the standard zlib compression that the other subformats use. It uses a SR64 Sparse Storage Scheme.
The basic USF file structure is a subformat of PSF.
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