Based on your request, it seems you are working with a video file titled and looking to "create a piece" (likely to trim, edit, convert, or extract a portion).
path and settings (choose "Keep original" or "Passthrough" for video/audio to avoid quality loss). Click "Start" to create the new, smaller piece. Based on your request, it seems you are
If you need only the audio or specific subtitle tracks, MKVToolNix is the industry standard for demuxing (separating) the tracks from the .mkv container. Open your software (MKVToolNix or HandBrake). Based on your request