Multiple languages are often embedded as UTF-8 plain text or image-based formats like PGS, which can be toggled on/off.
Modern players use ASICs or hardware-accelerated GPUs to decode these files efficiently.
MKV allows for multiple high-fidelity streams, such as DTS-HD Master Audio or Dolby TrueHD , alongside compressed formats like E-AC-3 (Dolby Digital Plus).