MKV is a popular container format used for video files. Sometimes, I need to change the headers of a file. For example, to set a different audio channel as default or to disable it and so on. All such header operations are easy to perform using the GUI tool of MKVToolNix.
To install the GUI tool:
$ sudo apt install mktoolnix-gui
mkvtoolnix-gui and click the Edit Headers section.
Open the MKV video file whose headers you want to edit. This section will be populated with all the video, audio, subtitle and other such header information. It can be expanded by clicking on the plus symbols.
To edit a particular header field, drill down to it and click on it. The right side of the GUI will show its current value. You can add, remove or edit the default values.
After you are done, we need to make sure that the resulting header is valid. To check this choose from above Header editor → Validate values.
If validation passes, choose from above Header editor → Save.
Tried with: MKVToolNix 8.8.0 and Ubuntu 16.04