The audio quality of the file is in True French, which implies that the audio track is in French, likely with a 5.1 or 7.1 channel layout. The audio codec used in MKV files is often AC-3 (Dolby Digital 5.1) or DTS (DTS 5.1), but without specific information, it's hard to determine the exact codec. However, given that it's a Blu-ray rip, it's likely that the audio quality is high, with clear and immersive sound.