What you need: MKVToolNix Time required: Depends on length of video
By Nick Peers
HOW TO...
When it comes to your media-streaming toolkit, make sure you leave space for MKVToolNix. You’ve got MakeMKV (www.makemkv.com) for ripping discs, and HandBrake (https://handbrake.fr) for converting them to space-saving (and universally compatible) formats, but what happens when you want to perform major surgery on a video file? That’s when you need MKVToolNix.
Despite the name, MKVToolNix can import most popular video formats, not just MKV. You can use it to combine files into one single video, split a video into separate files, and edit their properties. You can also rename commentary and subtitle tracks, so they’re easier to identify and select in compatible media players.
You can remove unwanted tracks from your video to save space (or even splice in a track from another source), and even construct your own chapter structure to help you navigate a lengthy clip quickly. It can also fix problems with files due to incorrect aspect ratio settings. Here we’ll explain the best ways to use it.
1Download MKVToolNix and add files
Go to www.snipca.com/47942 where you’ll find download links for all major operating systems. Click the blue Windows link below the Downloads heading to reveal installer and portable versions for both 32bit and 64bit.
When installed, open the program and you’ll find yourself at its primary screen, called the multiplexer. This lets you carry out all kinds of edits on your media files.
Start by right-clicking inside the ‘Source files’ box ( 1 in our screenshot) and choosing ‘Add files’. MKVToolNix may only export video files in MKV format, but you can import a wide range of media files into it. Click the ‘All supported media files’ dropdown menu next to the ‘File name:’ field to see just what it can work with – a mixture of video, audio and subtitle formats 2 .
Once you’ve opened a file, you’ll see information about its tracks (video, audio and subtitle) appear in the panel below it, split into multiple columns (right-click the column header to customise what’s shown). Available information includes the track type, the codecs used, whether it’s the default track chosen for playback, and a Properties field providing a summary about what’s in that track – the number of channels and bitrate if audio, or display resolution in pixels if video.
