.BCSAR File Extension

While the BCSAR format is similar to the BRSAR format, they are not exactly the same. The two formats have slightly different structures, so not all utilities that can open BRSAR files can open BCSAR files, and vice versa.

BCSAR files are stored in a .CIA file or 3DS cartridge's romfs/​sound directory. They contain audio files saved in the .BCSTM, BCWSD, BCSEQ, and .BCWAV formats.

You can extract the audio files a BCSAR file contains with Citric Composer (Windows), caesar (multiplatform), and BCSAR View (multiplatform). Note that these utilities are player-created, so may have limitations or function incorrectly at times.