.BCSTM Bestandsextensie

Often, 3DS games loop BCSTM files during gameplay, to provide unbroken background music during a level or repeat a sound effect at certain intervals. For this reason, BCSTM file often contain loop indicators, which tell a game how to loop the sound the file contains. (For example, a game may loop only a portion of a BCSTM file, as specified by an indicator.)

While BCSTM files usually contain official, original game sounds, gamers sometimes create custom BCSTM files, for use in modded 3DS games. For example, Super Smash Bros. players can use Brawl Custom Song Maker to convert WAV, .MP3, .OGG, or .FLAC files into BCSTM files, which they can insert into a game's BCSAR archive(s), using modding utilities.

You can open a BCSTM file and play the audio it contains with Foobar2000, after installing the vgmstream plug-in. You can also open and play BCSTM files with BrawlBox (Windows).

You can use Foobar2000 with the vgmstream plug-in installed to convert BCSTM files to .WAV and other common audio formats. You can also use BrawlBox to convert BCSTM files to WAV.

Game modders who want to convert BCSTM files to other proprietary Nintendo audio formats, including .BFSTM, BFSTP, .BFWAV, and .BCWAV, can use BCFSTM-BCFWAV-Converter (Windows) to do so.