This example demonstrates how to extract subtitle tracks from Matroska (.mkv) video files using the mkvtoolnix command-line suite. It shows the complete workflow, starting with installing mkvtoolnix via Homebrew, listing the container’s tracks with `mkvmerge -i`, identifying subtitle track IDs by their S_TEXT/UTF8 codec, and then extracting them into standalone .srt files with `mkvextract`. A batch script loops over all .mkv files in a directory using a for loop and sed to rename outputs, though it assumes uniform track IDs across files.