.brstm

A Binary Revolution Stream (.brstm) file is a file containing music and sounds. BRSTM files are used in many Wii games, such as NSMBW, Mario Kart Wii, and many more! The music inside the files can have defined loop points, to allow it to loop endlessly, used for stage songs, such as the Grassland or Underground theme.

Opening BRSTM Files
You can open BRSTM files using BrawlBox or BrawlCrate. Both tools also support playing these files.

File Header
The file begins with the header, which is 0x64 bytes. All lengths are written in Hexadecimal.

Sections
The rest of the file is written like an Adaptive differential pulse code modulation (ADPCM) file.

HEAD
The HEAD section is typically 256 bytes long.

It contains what appears to be a ADPCM Table, followed by a a YN1 & YN2 twice, which may control looping. The byte at 0x23 describes the number of channels.

The rest is unknown.

ADPC
The ADPC section contains what looks like another table.

DATA
The DATA section contains the ADPCM data, the sounds the file makes.