MKVtools is used for the creation and editing of MKV videos.

Features:

• Convert from a variety of video file formats like MKV, MP4, OGM and AVI into MKV videos..
• Can convert most videos without having to re-encode the video track and/or the audio track, so processing takes minutes instead of hours and no quality is lost.
• Simplified, intuitive user interface that takes the guess work out of processing MKV videos.
• Ability to convert various surround sound audio to 5.1 AC3 or 5.1 AAC.
• Intuitively select desired video, audio and/or subtitle tracks to process, with the ability to verify the selections using video preview.
• Define presets for one step automated encoding and track selections settings.
• Burn (i.e., hard code) subtitle tracks into the video, or mux (soft subtitles) from internal tracks or from external subtitle files commonly found on the internet.
• Control the font, size and positioning of the embedded subtitles.
• Split MKV videos into segments of a specified file size or by start/end time.
• Turn off an MKV video's header removal compression to allow more compatibility with playback and editing.
• Join MKV videos.
• Extract the selected tracks from MKV videos as individual video and/or audio files.
• Add jobs to a queue either individually or in batches via drag and drop so you can process multiple files overnight (registered copies only).
• Apply one setting to a group of files for easy batch creations (registered copies only).
• Enter a "Watch Mode" for which MKVtools will process all videos place in a defined folder (registered copies only).

Requirements:
OS X 10.9+
64-bit Intel