MKVToolNix

MKVToolNix is a comprehensive set of tools for creating, editing, and inspecting Matroska (MKV) video files. It provides both command-line utilities and a user-friendly GUI for tasks like merging multiple video, audio, and subtitle tracks into a single MKV file, splitting large files into smaller segments, and extracting specific tracks from existing files. The application is widely used by video enthusiasts, content creators, and media professionals who need to manipulate MKV containers without re-encoding the underlying video streams, preserving quality while performing operations like adding subtitles, changing track properties, or combining multi-part movies. It supports a vast range of input formats and codecs, making it an essential tool for video remuxing and media library management workflows.