Chapters allow you to skip to key points in a video. This is particularly useful if you are watching a recording of a meeting/conference and want to skip the introductions etc. This tutorial will show you how to easily add chapters to a MKV file using the mkvmerge tool on Ubuntu 16.04.
Firstly, install the mkvmerge command by installing the
sudo apt-get install mkvtoolnix -y
Now use your text editor of choice to create a simple text file using the "simple chapter format" as shown below (self-explanatory):
CHAPTER01=00:00:00.000 CHAPTER01NAME=Intro CHAPTER02=00:02:30.000 CHAPTER02NAME=Baby prepares to rock CHAPTER03=00:02:42.300 CHAPTER03NAME=Baby rocks the house
Now use mkvmerge to add that to your mkv file (this will remove any existing chapters in the file).
mkvmerge \ --chapters chapters.txt \ -o output.mkv \ input-file.mkv
Wait for the processing to complete (shou'dn't take long), and now you will be able to use your video-player's buttons to skip between chapters.
MPV player helpfully shows the chapter names on screen when you do this: